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Gestating gilts [n = 27; body weight (BW) = 158 ± 5.5 kg] were used to determine the effect of standardized ileal digestible (SID) sulfur amino acid (SAA) intake during late gestation on whole-body nitrogen (N) retention and subsequent litter performance. Gilts were assigned to one of two experimental diets that provided SAA at 60 or 200 % of estimated requirements during late gestation (0.29 and 0.92 % SID SAA, respectively; n = 15 and 12, respectively; Table 1 and 2). Each gilt received 2.53 kg of the assigned diet between gestation d 90 and farrowing; standard lactation and nursery diets were provided to gilts after farrowing and offspring after weaning, respectively. Gilt whole-body N balance was determined between d 107 and 109 of gestation using total urine collection and fecal grabsampling. After farrowing, litters were standardized to 13 piglets and were not offered creep feed. Wholebody N retention was greater in gilts fed the diet containing 0.92 vs. 0.29 % SID SAA in late gestation (27.2 vs. 19.3 ± 1.8 g/d; P < 0.05; Table 3), but the number of piglets born alive, litter birth weight, subsequent piglet growth rates, and litter size at weaning were not different between treatment groups. The post-weaning growth performance of offspring was also not influenced by maternal dietary treatment in late gestation (Table 4). At farrowing, the post-absorptive plasma concentration of Cys tended to be less (P = 0.072) and taurine was greater (P < 0.01) for gilts fed 0.92 vs. 0.29 % SID SAA in late gestation; however, there were no differences in plasma SAA metabolites concentrations for gilts at weaning or offspring at birth (Table 5. At weaning, offspring from gilts fed 0.92 % SID SAA had greater plasma homocysteine (P < 0.05) and plasma Cys concentrations (tendency; P = 0.072) vs. offspring from gilts fed 0.29 % SID SAA in late gestation. Three weeks after weaning, plasma taurine concentration was less (P < 0.05) for offspring from gilts fed 0.92 vs. 0.29 % SID SAA in late gestation (Table 6). Six weeks after weaning, plasma glutathione concentration tended to be less (P = 0.057) for offspring from gilts fed 0.92 vs 0.29 % SID SAA in late gestation. When SAA were fed below estimated requirements during late gestation, whole-body N retention was reduced, but fetal growth appeared to be maintained, likely at the expense of maternal N retention. Such divergences in dietary SAA supply in late gestation had no effect on subsequent offspring growth performance, but it appeared that offspring SAA metabolism was impacted until at least 6 wk after weaning. The influence of differences in sulfur AA metabolites on offspring performance beyond the nursery phase remains unknown. Therefore, carry-over effects of maternal SAA supply in late gestation should be considered when developing feeding recommendations for gestating gilts. [ABSTRACT FROM AUTHOR]

Twenty-eight mixed-parity sows (Line 241; DNA) and their offspring were used to evaluate live yeast supplementation during lactation with or without a pre/probiotic combination during the nursery period on lactation performance, lifetime growth performance, and immune response. On day 110 of gestation, sows were allotted to a lactation diet with or without a live yeast probiotic (0.10% Actisaf Sc 47 HR+; Phileo by Lesaffre, Milwaukee, WI). At weaning, their offspring (350 pigs; initially 6.1 ± 0.02 kg) were randomly assigned in a 2 × 2 factorial with main effects of sow treatment and nursery treatment consisting of a control diet or a diet with a yeast cell wall prebiotic and Bacillus subtilis probiotic (0.10% YB; Phileo by Lesaffre, Milwaukee, WI) fed for 42 d followed by common diets fed until marketing. Two nursery pens were combined into 1 finishing pen, such that there were 5 and 10 pigs per pen with 17 or 18 and 8 or 9 replications per treatment during the nursery and finishing periods, respectively. There were no significant effects of yeast supplementation on lactation performance (P  ≥ 0.079). There was a sow × nursery diet interaction (P  = 0.024) on nursery ADG. Pigs from yeast-fed sows had increased ADG when fed control nursery diets compared to pigs from control sows fed the control nursery diet with pigs fed pre/probiotic nursery diets intermediate, regardless of sow diet. Pigs from yeast-fed sows tended (P  = 0.067) to have greater final body weight (BW) (day 165). A subset of pigs was sampled throughout their lifetime to determine serum porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae antibody sample-to-positive (S/P) ratios and percentage inhibition of Lawsonia intracellularis. There was a tendency for a PCV2 S/P ratio sow diet × day interaction (P  = 0.097) where progeny from yeast-fed sows had higher PCV2 S/P ratios at 101 d of age compared to control sow progeny (P  = 0.046). There was a PCV2 S/P ratio nursery diet × day interaction (P  = 0.036) where pigs fed a pre/probiotic combination had reduced S/P ratios at 66, 78, and 162 d of age (P  ≤ 0.022); however, at 22 d of age pigs fed a pre/probiotic combination tended to have an increased S/P ratio (P  = 0.051). In conclusion, the effects of combining a yeast probiotic in lactation diets and a pre/probiotic in nursery diets were not additive. However, feeding a live yeast probiotic during lactation resulted in tendencies (P  ≤ 0.10) for increased progeny final BW and hot carcass weight. [ABSTRACT FROM AUTHOR]

Two experiments evaluated the effects of precision feeding standardized ileal digestible (SID) Lys during lactation. Sows were blocked by parity and allotted to treatment on day 2 of lactation. In both experiments, sow body weight (BW), backfat (BF), loin depth (LD), and estimated N excretion were evaluated as well as litter growth performance. In experiment 1, 95 sows and litters were used. Three dietary treatments were provided using 2 diets: a low (0.25% SID Lys) and high Lys diet (1.10% SID Lys). Treatments included a control diet (1.10% SID Lys) fed throughout lactation, and NRC or INRA treatment curves for Lys intake. Sows fed NRC or INRA treatment curves received blends of low and high Lys diets using a computerized lactation feeder (Gestal Quattro Opti Feeder, Jyga Technologies, St-Lambert-de-Lauzon, Quebec, CA) to target a specific Lys intake each day of lactation based on NRC and INRA models for parity and litter size. In experiment 2, 56 sows and litters were used with 3 treatments, a control diet (1.10% SID Lys fed throughout lactation) and either a static or dynamic blend curve. For both curve treatments, low (0.40% SID Lys) and high Lys (1.10% SID Lys) diets were blended to reach target Lys intake. The difference between the static and dynamic curves was that the dynamic curves were adjusted based on actual Lys intake and static curves were not. Lysine intake curves were based on NRC model estimates, but targets were increased by 20% to target average Lys intake of 60 g/d across parities based on results of experiment 1. In both experiments, no differences (P  > 0.05) in sow average daily feed intake or sow BW, BF, or LD change were observed. Sows fed the control diets had greater Lys intake (grams per day; P  < 0.05) compared to sows fed either of the blended treatment curves. In experiment 1, pigs from sows fed the control diet had greater (P  < 0.05) BW at weaning and preweaning average daily gain (ADG) compared to sows fed the INRA treatment curve, with pigs from sows fed the NRC treatment curve intermediate. However, in experiment 2, no differences (P  > 0.05) were observed in pig weight at weaning or ADG. In both experiments, sows fed the blended treatment curves had lower (P  < 0.05) calculated N excretion. In summary, for a litter size of 13.5 weaned pigs, 60 g/d of SID Lys is sufficient to maximize litter weight gain and can be achieved through blending low and high Lys diets. Precision feeding reduced N excretion compared to feeding a single diet throughout lactation. [ABSTRACT FROM AUTHOR]

Postpartum dysgalactia syndrome (PDS) is a condition affecting periparturient sows, characterized by a reduction in milk and colostrum synthesis shortly after farrowing. Insufficient milk production results in substantial economic losses due to increased piglet morbidity/mortality and premature sow culling. Since PDS develops within a few days following farrowing, the study objectives were to determine if periparturient immune cell profiles and circulating biomarkers differ in sows affected by PDS. We hypothesized differences in immune cells, circulating analytes, and inflammatory markers would exist at farrowing in sows that subsequently developed PDS compared to healthy herd-mates. Thirty-six sows with PDS symptoms were matched by parity and day of lactation with 36 healthy control (CON) sows. Diagnosis of PDS (timepoint 2) occurred on average 9.25 ± 2.67 d after farrowing. Blood samples and litter weights were collected at farrowing (timepoint 1) and at the onset of clinical PDS (timepoint 2). Piglets from PDS sows had lower average daily gain and higher mortality than piglets from CON (P  < 0.01). Aspartate aminotransferase was increased (20%; P  ≤ 0.06) in PDS sows compared to CON at both timepoints. Additionally, blood urea nitrogen was increased in PDS sows at timepoint 1 and timepoint 2 (13%; P  = 0.08 and 16%; P  = 0.01, respectively). At timepoint 2, total protein, globulin, magnesium, and cholesterol were increased (P  ≤ 0.03) while γ-glutamyl transferase and albumin were decreased (P  ≤ 0.02) in PDS sows. Lipopolysaccharide-binding protein, an inflammatory biomarker, was increased (48%; P  = 0.07) at timepoint 2 in PDS compared to CON sows. Collectively, these data indicate PDS sows have altered metabolism and appear immune activated compared to healthy herd-mates, and further investigation is needed to determine if PDS can be predicted at farrowing. [ABSTRACT FROM AUTHOR]

The immune response varies between pigs, as not all pigs have the same response to a stressor. This variation may exist between individuals due to body weight (BW) or body composition, which may impact the capacity for coping with an immune challenge (IC). Tryptophan (Trp), threonine (Thr), and methionine (Met) requirements might also play a considerable part in supporting immune system activation while reducing variation between pigs; however, the latter has yet to be reported. This exploratory study investigated the effect of initial BW (light vs. heavy-weight) and supplementation of Trp, Thr, and Met above National Research Council (NRC) requirements on feeding behavior and the coping capacity of growing pigs under an IC. Eighty gilts were categorized into 2 groups according to BW: light-weight (LW , 22.5 kg) and heavy-weight pigs (HW , 28.5 kg). Both BW groups were group-housed for a 28-d trial in a good or poor sanitary condition (SC). Pigs within a poor SC were orally inoculated with 2 × 109 colony units of Salmonella Typhimurium, and fresh manure from a pig farm was spread on the floor. Pigs within good SC were not inoculated, nor was manure spread. Two diets were provided within each SC: control (CN) or supplemented (AA+) with Trp, Thr, and Met at 120% of NRC recommended levels. A principal component analysis was performed in R, and a feeding behavior index was calculated in SAS. Results showed that LW and HW pigs were clustered separately on day 0, where LW pigs had a positive correlation with body lipid percentage (r  = 0.83), and HW pigs had a positive correlation with body protein percentage (r  = 0.75). After the IC, the cluster configuration changed, with diets influencing LW more than HW pigs within poor SC. On day 14, LW fed AA + diet in poor SC was clustered separately from LW pigs fed CN diet, whereas LW fed AA + and CN diets in good SC were clustered together. For feeding behavior, in both analyzed periods (period 1: days 7 to 14; period 2: days 21 to 28), LW had lower total feed intake and shorter meals than HW pigs (P  < 0.10), independent of the SC. Furthermore, LW pigs fed AA + diet had a more regular feed intake pattern than those fed CN diet, while a more irregular pattern was observed for HW pigs fed AA + diet than CN diet at period 2. These findings suggest that supplementing Trp, Thr, and Met above requirements may be a nutritional strategy for LW pigs under IC by improving feed intake regularity and reducing the probability of being susceptible to IC. [ABSTRACT FROM AUTHOR]

The objective of the present experiment was to determine the minimum adaptation period for total tract digestibility experiments in gestating and lactating sows using the indigestible index method. Five gestating and 5 lactating sows at parities 3 to 5 were used. An indigestible index of 0.5% chromic oxide was supplemented to a diet based on corn and soybean meal. The daily feed allowance for gestating sows was 2 kg and 2 equal meals were provided to the sows. Lactating sows were fed 6 kg of feed per day in 3 equal meals. After feeding a diet without supplemental chromic oxide for 5 d, index-supplemented diets were provided to the gestating and lactating sows. Feces were collected at 24-h intervals for 9 and 7 d from gestating and lactating sows, respectively. Fecal Cr concentrations increased linearly (P  < 0.001) and quadratically (P  < 0.001) with collection time in both gestating and lactating sows. Minimum adaptation periods were estimated by one-slope broken-line model. The break point of Cr concentrations in feces was day 7.2 (SE = 0.3) in the gestating sows and day 4.2 (SE = 0.2) in the lactating sows, respectively. Apparent total tract digestibility of dry matter, organic matter, and energy on day 4 was less (P  < 0.001) than that on days 8 to 9 in gestating sows fed the experimental diet with a 2-kg feed allowance. In lactating sows fed the experimental diets with a 6-kg feed allowance, the apparent total tract digestibility of dry matter, organic matter, and energy on day 3 was less (P  < 0.05) than that on days 5 to 7. In conclusion, at least 8 d of adaptation period are required for gestating sows to determine total tract digestibility using Cr as the indigestible index method whereas 5 d of adaptation period are required for lactating sows. An insufficient adaptation period results in lower digestibility values. [ABSTRACT FROM AUTHOR]

A total of 480 newly weaned pigs (PIC 337 × 1050; Genus, Hendersonville, TN) with an initial body weight (BW) of 6.20 ± 0.61 kg were used in a dose–response study to investigate the impact of increasing standardized ileal digestible (SID) Arg:Lys on nursery pig growth performance. At weaning, pigs were placed into 48 pens with 5 barrows and 5 gilts per pen. Pens were randomly assigned to 1 of 6 dietary treatments. The experimental diets were formulated with increasing SID Arg:Lys, achieved by substituting corn starch, glycine, and l -alanine with l -arginine, resulting in SID Arg:Lys ranging from 45% to 145%. Diets were sublimiting in SID Lys and exceeded all other essential amino acid requirements. The experimental diets were fed across two feeding phases from days 0 to 10 and 10 to 27, with adjustments made to account for the Lys requirement of the pigs. All pens were placed on a common diet for the remaining 14 d of the study to evaluate carryover effects. Pigs and feeders were weighed at the start and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed according to a linear regression model, which included the linear and quadratic effects of SID Arg:Lys and initial BW. Pen was the experimental unit, and results were considered significant at P  ≤ 0.05 and a tendency at 0.50 <  P  ≤ 0.10. From days 0 to 27, Arg:Lys tended to have a quadratic effect on ADFI (P  = 0.058), where 97.00 ± 7.631% SID Arg:Lys maximized feed intake. Similarly, Arg:Lys had a quadratic impact on ADG (P  = 0.046), where ADG was maximized at a SID Arg:Lys of 95.65 ± 7.165. Correspondingly, Arg:Lys had a quadratic effect on pig BW on day 27 (P  = 0.014). These effects were carried through the end of the study, where Arg:Lys quadratically impacted days 0 to 41 ADFI (P  = 0.006), ADG (P  = 0.077), and day 41 BW (P  = 0.028). There was no evidence of an effect of SID Arg:Lys on G:F throughout the study (P  ≥ 0.315). In conclusion, SID Arg:Lys quadratically impacted ADFI and ADG in 6- to 13-kg nursery pigs, where ADFI was maximized at a SID Arg:Lys of 97.00% (95% CI [81.6%, 112.4%]), and ADG was maximized at a SID Arg:Lys of 95.65% (95% CI [81.2%, 110.1%]). Together, these data suggest that the SID Arg:Lys requirement of nursery pigs is at least 81%, based on the lower bounds of the 95% CI for maximum ADG and ADFI, and excessive Arg supplementation may negatively affect growth performance. [ABSTRACT FROM AUTHOR]

Gestating sows are often fed a single diet throughout their gestation cycle, leading to situations of nutrients deficiency or excess at the individual level. The purpose of this study was to characterize, over 3 consecutive cycles, the impact of a precision feeding (PF), i.e. dietary supplies adjusted at individual level in terms of quantity (energy intake) and quality (standardized ileal digestible (SID) lysine (Lys) intake), on gestating sows' productive performance, feeding behavior, environmental outputs, and health status compared with sows fed a conventional feeding (CF , i.e. fixed SID Lys intake). At the start of the trial, 2 batches of 20 Landrace × Large White gestating sows were allocated to one of the 2 feeding strategies (PF vs. CF), based on their parity (1, 2, or 3 and more), body weight, and backfat thickness (BT) 3 days after insemination. The PF strategy consisted in mixing with automatic feeders 2 iso-energetic diets (9.8 MJ/kg of net energy with 3.3 and 8.5 g SID Lys/kg, respectively) in variable proportions at individual and daily levels, whereas for the CF strategy these proportions remained constant throughout gestation (73% and 27%, respectively, resulting in an SID Lys concentration of 4.7 g/kg). Sows were followed over 3 consecutive gestations and the sows remained allocated to the same strategy throughout the study. Some sows were culled before the end of the study and were replaced by other sows who therefore performed only 1 or 2 gestations during the study. Thus, 106 gestations and lactations from 51 sows were fully studied and their data analyzed. The PF strategy allowed the sows to reach more closely the expected BT values at farrowing across cycles than the CF strategy (P  < 0.001). The PF sows consumed 16% less SID Lys per gestation than the CF sows (P  < 0.001), resulting in a 4% improvement in N efficiency (P  < 0.001), with no impact on performance at farrowing (P  > 0.10). The sows consumed their daily ration in a single visit whatever the feeding strategy (P  = 0.41), but CF sows spent more time in the feeder in cycles 2 and 3 (P  < 0.001). Thus, compared to the CF strategy implemented by farmers, the individual and daily nutritional supplies implemented with the PF strategy were more efficient in enabling sows to achieve body condition objectives at farrowing over the long term, also with a reduced SID Lys intake and an improved N efficiency without negative impact on farrowing performances. [ABSTRACT FROM AUTHOR]

Fifty gilts (initial body weight [BW] 190.7 ± 4.2 kg) were recruited on day 85 of gestation and were used until day 19 of lactation to assess the dose–response of inactivated yeast via hydrolyzation (HY) inclusion on offspring growth and immunoglobulin (Ig) transfer prior to weaning. Gilts were assigned to one of the 5 experimental diets: a control with no HY (HY0) or inclusion of 0.25% (HY0.25), 0.5% (HY0.5), 1.0% (HY1.0), or 1.2% (HY1.2) HY. Gilts were weighed on days 85 and 110 of gestation and days 1 and 19 (weaning) after farrowing. Offspring were weighed on days 1 and 19 of age. On lactation day 1 (approximately 24 h after farrowing), colostrum, gilt plasma, and plasma from 2 median BW piglets were collected and on day 19, plasma from each gilt and 2 median BW piglets per litter were collected for determination of Ig concentrations. Contrast statements were used to assess the linear, quadratic, cubic, and quartic effects of HY inclusion. The inclusion of HY had minimal effects on gilt BW or litter characteristics at birth (total number born and born alive, piglet birth weight). Lactation average daily feed intake of the gilts tended to increase then decrease with increasing HY inclusion (quadratic; P  = 0.085). Piglet preweaning average daily gain (linear, quadratic, and quartic; P  < 0.05) and BW at weaning (quadratic and quartic; P  < 0.05) increased then decreased with increasing HY inclusion. On lactation day 1, colostrum and gilt plasma Ig concentrations were not affected by dietary treatment (P  > 0.10) but piglet IgA and IgM decreased then increased with HY inclusion level (cubic; P  < 0.05). On lactation day 19, piglet plasma IgG tended to increase with HY inclusion (linear; P  = 0.099). In summary, increasing HY inclusion in late gestating and lactating gilt diets improved immune transfer in the first 24 h after birth and piglet preweaning growth rates and BW at weaning. Therefore, maternal feeding of HY could be used as a strategy to improve offspring immunocompetence and BW at weaning, with possible carryover benefits for the postweaning phase. [ABSTRACT FROM AUTHOR]

This study evaluated the ability of 2 penetrating captive bolt (PCB) types (PISTOL, INLINE) to reach and disrupt the thalamus when applied in 2 placements (FRONTAL, BEHIND EAR) to chilled cadaver heads (N  = 60) from sows >200 kg. Heads were randomly distributed across 6 treatments (n  = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR-PISTOL, and BEHIND EAR-NO SHOT. The FRONTAL shot was placed 3.5 cm superior to the optic orbits at the midline; the BEHIND EAR shot was placed directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For INLINE treatments, a Jarvis PAS—Type C 0.25R Super Heavy Duty PCB with a Long Bolt and 6.0 GR power loads was used. For PISTOL treatments, a Jarvis PAS—Type P 0.25R Pistol PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 GR power loads was used. Heads were split along the bolt with a band saw. Tissue depth measurements are reported as Mean ± SE followed by 97.5% one-sided upper reference limit (URL). Total tissue thickness was less (P  < 0.0001) at the FRONTAL (56.31 ± 1.76 mm; URL: 73.17 mm) than the BEHIND EAR placement (95.52 ± 3.30 mm; URL: 126.53 mm). Thalamic depth was less (P  < 0.0001) at the FRONTAL (78.31 ± 1.32 mm; URL: 88.19 mm) than the BEHIND EAR placement (111.86 ± 3.22 mm; URL: 135.99 mm). The effective angle was greater (P  < 0.0001) at the FRONTAL (4.72 ± 0.20°) than the BEHIND EAR placement (3.22 ± 0.17°). Potential for bolt-brain contact was not different (P  = 1.0000) between FRONTAL-INLINE (10/10, 100% ± 0.01%), FRONTAL-PISTOL (10/10, 100% ± 0.01%), BEHIND EAR-INLINE (9/10, 90% ± 9.49%), and BEHIND EAR-PISTOL (10/10, 100% ± 0.01%); brain damage (P  = 0.5577) between FRONTAL-INLINE (9/9, 100% ± 0.02%), FRONTAL-PISTOL (10/10, 100% ± 0.02%), BEHIND EAR-INLINE (4/10, 40% ± 15.49%), and BEHIND EAR-PISTOL (1/10, 10% ± 9.49%); potential for bolt-thalamus contact (P  = 0.0683) for FRONTAL-INLINE (2/10, 20% ± 12.65%), FRONTAL-PISTOL (8/10, 80% ± 12.65%), BEHIND EAR-INLINE (7/9, 77.78% ± 13.86%), and BEHIND EAR-PISTOL (9/9, 100% ± 0.02%); or thalamic damage (P  = 0.8041) for FRONTAL-INLINE (1/10, 10% ± 9.49%), FRONTAL-PISTOL (1/10, 10% ± 9.49%), BEHIND EAR-INLINE (2/8, 25% ± 15.31%), and BEHIND EAR-PISTOL (0/9, 0% ± 0.00%). The FRONTAL placement with an INLINE PCB may present the least risk of failure for the PCB euthanasia of mature sows >200 kg body weight due to less total tissue thickness and thalamic depth, greater effective angle, and prevalent brain damage. [ABSTRACT FROM AUTHOR]

The negative effects of heat stress on swine reproduction have been well documented and the recent global warming trend caused by climate change is leading to more days with high temperatures every year. This has caused a reduction in litter trait performance of Landrace sows in Taiwan, a country extending across tropical and subtropical oceanic zones. Therefore, this study developed a modified model to determine which stages of pregnancy, before, early, middle, and late, had the largest impacts of heat stress on litter traits. A reaction norm model (RNM) was used to identify sows with high resilience to heat stress for litter traits followed by analysis of the modified model. Data from Landrace sows were collected from 2 farms in Taiwan between 2008 and 2021. A total of 11,059 records were collected for total number born (TNB), number born alive (NBA), and stillborn rate (STBR). The results showed that the heritabilities of TNB, NBA, and STBR were 0.170, 0.115, and 0.077, respectively. These results were similar between the conventional model and the modified model. In the modified model, the before and early stages of sow pregnancy were the significant periods for TNB and NBA (P  < 0.05), while the early and middle stages were significant for STBR (P  < 0.05). According to the RNM results, the heritability estimates for TNB, NBA, and STBR were 0.23 to 0.11, 0.18 to 0.08, and 0.10 to 0.04, respectively, showing a decrease from low temperature-humidity index (THI) to high THI. The minimum genetic correlations between the highest and the lowest THI for TNB, NBA, and STBR were 0.85, 0.64, and 0.80, respectively. The results of the RNM for breeding value showed re-ranking across THI values. In conclusion, similar results were obtained for heritability when the model was modified for heat stress estimation. Yet re-ranking of breeding values across THI could help farmers to select not only for improved litter trait performance but also for heat stress resilience of Landrace sows in Taiwan. [ABSTRACT FROM AUTHOR]

Variation in feed intake results in nearly 20% of sows consuming less than the recommended lysine (Lys) intake for lactating sows. The Lys requirement for lactating sows is based on litter size and piglet average daily gain which influences milk production. Litter size continues to increase every year causing the need for routine reevaluation of nutrient requirements. If dietary inclusion levels are not continuously adjusted this can lead to inadequate daily Lys and energy intake and may negatively impact sow body condition and litter performance. The objective was to characterize the average daily feed intake (ADFI) of sows and define feed intake patterns and their effects on sow body weight, farrowing performance, litter performance, and subsequent farrowing performance. ADFI during lactation was recorded for 4,248 sows from 7 independent research studies. Data collection occurred from November 2021 through November 2023 at a commercial breed-to-wean facility in western Illinois. Each sow was categorized as: consistently low intake (< 5.5 kg/d) throughout the lactation (LLL); low intakes (< 5 kg/d) in the first week, then gradually increased throughout the rest of the lactation period (LHH); gradual increase in intake throughout lactation with no drop and a peak intake after day 10 of lactation (gradual); rapid increase in intake with no drop and the peak intake met before day 10 (rapid); a major drop in feed intake (> 1.6 kg decrease for ≥ 2 d) any time during lactation (MAJOR); minor drop (≤ 1.6 kg for ≥ 2 d; MINOR). Sows were also separated into low (quartile 1; ≤ 25%), average (quartile 2 through 3), or high feed intake (quartile 4; ≥ 75%) by parity (P1, P2, P3+). Sows in the LLL category were younger in parity, had the greatest preweaned mortality, weaned the lightest average pigs, and experienced the greatest loss in body weight percentage compared with sows in all other feed intake categories. Furthermore, sows in the LLL and LHH categories had one fewer subsequent pig born compared with sows in the other four categories. These data support historical findings that feed intake patterns directly contribute to current litter farrowing performance. Lactation intake patterns also influence subsequent farrowing performance. Identifying under-consuming sows that are likely Lys and energy deficient allows producers opportunities to promote consistent, adequate daily intakes to these groups and mitigate negative impacts on sow and litter performance. [ABSTRACT FROM AUTHOR]

Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, causes endocrine disruption and porcine reproductive dysfunction. Heat stress (HS) occurs when exogenous and metabolic heat accumulation exceeds heat dissipation. Independently, HS and ZEN both compromise swine reproduction; thus, the hypothesis investigated was two-pronged: that ZEN exposure would alter the ovarian proteome and that these effects would differ in thermal neutral (TN) and HS pigs. Pre-pubertal gilts (n  = 38) were fed ad libitum and assigned to either (TN: 21.0 ± 0.1 °C) or HS (12 h cyclic temperatures of 35.0 ± 0.2 °C and 32.2 ± 0.1 °C). Within the TN group, a subset of pigs were pair-fed (PF) to the amount of feed that the HS gilts consumed to eliminate the confounding effects of dissimilar nutrient intake. All gilts orally received a vehicle control (CT) or ZEN (40 μg/kg/BW) resulting in six treatment groups: thermoneutral (TN) vehicle control (TC; n  = 6); TN ZEN (TZ; n  = 6); PF vehicle control (PC; n  = 6); PF ZEN (PZ; n  = 6); HS vehicle control (HC; n  = 7); or HS ZEN (HZ; n  = 7) for 7 d. When compared to the TC pigs, TZ pigs had 45 increased and 39 decreased proteins (P  ≤   0.05). In the HZ pigs, 47 proteins were increased and 61 were decreased (P  ≤   0.05). Exposure to ZEN during TN conditions altered sec61 translocon complex (40%), rough endoplasmic reticulum membrane (8.2%), and proteasome complex (5.4%), asparagine metabolic process (0.60%), aspartate family amino acid metabolic process (0.14%), and cellular amide metabolic process (0.02%) pathways. During HS, ZEN affected cellular pathways associated with proteasome core complex alpha subunit complex (0.23%), fibrillar collagen trimer (0.14%), proteasome complex (0.05%), and spliceosomal complex (0.03%). Thus, these data identify ovarian pathways altered by ZEN exposure and suggest that the molecular targets of ZEN differ in TN and HS pigs. [ABSTRACT FROM AUTHOR]

Fifty-two multiparous sows (average parity 3.1 ± 0.9 and initial BW 245.6 ± 32.5 kg) were used to evaluate the effects of dietary standardized ileal digestible (SID) Lys-to-net energy (NE) ratios on nitrogen (N) utilization throughout a 24-d lactation period. Sows were randomly assigned to one of five isoenergetic feeding programs that provided equally spaced and increasing SID Lys-to-NE ratios between 2.79 and 5.50 g SID Lys/Mcal NE. The feeding programs were generated by blending the two extreme diets in varying proportions and were provided to sows immediately after farrowing (day 1) and until weaning at day 24 ± 1. Nitrogen balances were conducted between days 4 and 7, 12 and 15, and 20 and 23 ± 1 of lactation to represent weeks 1, 2, and 3, respectively, using total urine collection and fecal grab sampling. Contrast statements were used to determine the linear and quadratic effects of increasing Lys-to-NE ratios. Linear and quadratic broken-line and polynomial quadratic (QPM) models were used to determine the optimum dietary Lys-to-NE ratios for N retention in milk. The Bayesian information criterion was used to assess the best fit. Feeding program did not influence sow average daily feed intake (5.8 ± 0.1 kg), BW change (−8.2 ± 3.1 kg), or change in back fat thickness (−2.6 ± 0.7 mm) over the 24-d lactation period, but piglet average daily gain increased with dietary SID Lys-to-NE ratio (linear; P  < 0.05). Sow N intake increased with increasing dietary Lys-to-NE ratio in weeks 2 and 3 (linear; P  < 0.001). Whole-body N retention (N intake − N output in urine and feces) increased with increasing dietary Lys-to-NE ratio in all weeks (linear; P  < 0.05). The N retention in milk tended to increase then decrease with increasing dietary Lys-to-NE ratio in weeks 1 and 2 (quadratic; P  = 0.051 and P  = 0.081) and the QPM showed optimal milk N retention at 4.28, 4.42, and 4.67 g Lys/Mcal NE for weeks 1, 2, and 3, respectively. Maternal N retention (N intake − N output in urine, feces, and milk) decreased and then increased in week 1 (quadratic; P  < 0.01) and increased in weeks 2 and 3 (linear; P  < 0.01) with increasing dietary Lys-to-NE ratio. Therefore, the SID Lys-to-NE ratio necessary to optimize milk N output is dynamic throughout lactation. A two-diet feeding program could be created to match optimal weekly or daily SID Lys-to-NE ratios, which could lead to improved piglet ADG and body weights at weaning. [ABSTRACT FROM AUTHOR]

Penetrating captive bolt (PCB) is a common method of euthanasia for swine but has not been evaluated for mature swine < 200 kg body weight (BW). The objectives were to determine tissue depth, brain contact plane, and visible brain tissue damage (brain damage[BD]) for the common FRONTAL (F) and alternative TEMPORAL (T) and BEHIND EAR (BE) placements for PCB use on sows and boars weighing < 200 kg. Cadaver heads were obtained from 30 sows and 30 boars (estimated BW, mean ± SD; sows: 165.8 ± 22.4 kg; boars: 173.6 ± 21.4 kg) from a slaughter establishment after electrical stunning and exsanguination. Heads were cooled at 2 to 4 °C for approximately 64 h. A Jarvis PAS-Type P 0.25R PCB with a Long Stunning Rod Nosepiece Assembly and a 3.5 GR power load was used for all PCB applications at the following placements: F–3.5 cm superior to the optic orbits at midline, T–at the depression posterior to the lateral canthus of the eye within the plane between the lateral canthus and the base of the ear, or BE–directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For sows, the bolt path was in the brain for 10/10 (100.0%, 95% CI: 69.2% to 100.0%) F, T, and BE heads. In heads that could reliably be assessed for BD, BD was detected in 10/10 (100.0%, 95% CI: 69.2% to 100.0%) F heads, 9/9 (100.0%, 95% CI: 66.4% to 100.0%) T heads, and 0/10 (0.0%, 95% CI: 0.0% to 30.1%) BE heads. For boars, the bolt path was in the plane of the brain for 8/9 (88.9%, 95% CI: 51.8% to 99.7%) F heads, 9/10 (90.0%, 95% CI: 55.5% to 99.7%) T heads, and 11/11 (100.0%, 95% CI: 71.5% to 100.0%) BE heads. In heads that could reliably be assessed for BD, BD was detected in 8/9 (88.9%, 95% CI: 51.7% to 99.7%) F heads, 7/10 (70.0%, 95% CI: 34.8% to 93.3%) T heads, and 4/11 (36.4%, 95% CI: 10.9% to 69.2%) BE heads. Tissue depth was reported as mean ±  SE followed by 97.5% one-sided upper reference limit (URL). For sows, total tissue thickness differed (P  < 0.05) between placements (F: 49.41 ± 2.74 mm, URL: 70.0 mm; T: 62.83 ± 1.83 mm, URL: 76.6 mm; BE: 84.63 ± 3.67 mm; URL: 112.3 mm). Total tissue thickness differed (P  < 0.05) between placements for boars (F: 54.73 ± 3.23 mm, URL: 77.6 mm; T: 70.72 ± 3.60 mm, URL: 96.3 mm; BE: 92.81 ± 5.50 mm; URL: 135.3 mm). For swine between 120 and 200 kg BW, the F placement may have the greatest likelihood for successful euthanasia due to the least total tissue thickness and may present less risk for failure than the T and BE placements. [ABSTRACT FROM AUTHOR]

This paper presents a non-contact method for the detection of changes in sow vulva size in a group pen. The traditional approach to estrus detection is manually pressing down on the back of the sow to elicit standing responses; however, this method causes undue distress for sows not in estrus. When a sow is in estrus, the vulva is red and swollen due to the presence of endocrine. Monitoring changes in vulva size to detect estrus with as little impact on the sow as possible is the focus of this study. This is achieved using a single camera combined with a deep learning framework. Our approach comprises two steps: vulva detection and vulva size conversion. Images of sows of Yorkshire, Landrace, and Duroc breeds were collected in group housing, and the vulva was detected through artificial markers and the network architecture of YOLO v4. Based on the internal and external parameters of the camera, the detected size was converted into millimeters and the results of manual measurement (MM) and automatic calculation combined to calculate the size of the vulva. Analysis of the calculated size compared with MM indicates that the object recognition rate of the system exceeds 97.06%, with a size error of only + 1.70 to −4.47 mm and high-calculation efficiency (>2.8 frames/s). Directions for future research include the automatic detection of pig width. [ABSTRACT FROM AUTHOR]

Gestating gilts (n = 70; 166 ± 13 kg initial body weight at d 31 of gestation) were used to determine the dietary standardized ileal digestible (SID) Methionine (Met) content required to optimize wholebody nitrogen (N) retention versus the appearance of biomolecules derived via Met metabolism. On d 102 of gestation, gilts were randomly assigned to one of seven dietary treatments that provided between 50 and 150% of estimated SID Met requirements for late gestation gilts (0.10 to 0.30% SID Met). All other indispensable amino acids were supplied at least 20% above estimated requirements (NRC, 2012). A N balance (total urine collection and fecal grab sampling) was conducted for each gilt between days 109 and 112 of gestation, blood samples were collected on day 109 after a 24-h fasting period for analyses of plasma amino acids, homocysteine (Hcys), and reduced glutathione (GSH). Contrast statements were used to determine linear and quadratic effects of dietary SID Met levels. Linear and quadratic broken-line and polynomial quadratic models were used to determine the optimum level of SID Met for whole-body N retention and plasma concentrations of Hcys and GSH. Whole-body N retention increased with increasing dietary Met (linear and quadratic; P < 0.001; Table 1). Plasma concentrations of Hcys increased with increasing dietary Met (linear; P < 0.05). Glutathione tended to decrease and then increase at dietary SID Met greater than 0.20% (quadratic; P = 0.061; Table 2). Plasma glutamine increased with increasing dietary SID Met (linear; P < 0.01). Histidine increased then decreased at dietary SID Met greater than 0.20% (quadratic; P < 0.05), other amino acids were not influenced by dietary treatment. Linear and quadratic broken-line models described a lower breaking point for whole-body N retention, plasma Hcys, and plasma GSH compared with the quadratic polynomial model (0.154% and 0.155% vs. 0.226%, 0.185% and 0.188% vs. 0.328%, and 0.114% and 0.124% vs. 0.224% SID Met, respectively). The Bayesian information criterion (BIC) indicated that the quadratic polynomial model best fit the data versus the linear and quadratic brokenline models for plasma GSH (BIC 317.9 vs. 320.3 and 322.6, respectively; Graphic 1). However, the fits were similar among models for whole-body N retention (BIC 385.2 vs. 384.6 and 386.9, respectively; Graphic 2) and Hcys (BIC 465.5 vs. 465.6 and 467.9, respectively; Graphic 3). Based on the best fit (quadratic polynomial) model 0.226% SID Met is required to optimize whole-body N retention for late gestation gilts which is greater than that recommended by the NRC (2012; 0.20% SID Met). It appears that gilts have further capacity for Met transmethylation since the plasma Hcys breakpoint occurred at a greater dietary SID Met level than for whole-body N retention, though the impact on transsulfuration and remethylation pathways cannot be discounted. Therefore, greater feeding levels of SID Met might be required to maximize both protein and non-protein utilization of Met. [ABSTRACT FROM AUTHOR]

Iron deficiency anemia is a significant problem in piglets, as they are born with insufficient iron stores for supporting their rapid body growth. Further, sows' milk contains inadequate iron levels for meeting the demands of piglet rapid growth in the pre-wean stage. The forms of iron present in the milk are essential to understanding bioavailability and potential routes for supplementing iron to mitigate iron deficiency anemia in piglets. Recently, our studies showed that H-ferritin (FTH1) is involved in iron transport to different tissues and can be used as an oral iron supplement to correct iron deficiency in rats and monkeys. In this study, we investigate the FTH1 levels in colostrum and milk in Yorkshires-crossbred sows (n = 27) and collected samples at the 1st, 15th, and 28th days of lactation to measure FTH1. Colostrum and milk were found to have FTH1, but there is no significant difference between the different days of lactation. FTH1 has been observed to be enriched in extracellular vesicles (EVs) of other species, and therefore examined the EVs in the samples. Colostrum-derived EVs were enriched with L-ferritin compared to FTH1, while in milk-derived EVs, only FTH1 was detected (P = 0.04). In milk-derived EVs, FTH1 was significantly higher (P = 0.021; P = 006) than FTH1 in colostrum-derived EVs. Furthermore, FTH1 levels of milk-derived EVs were significantly higher (P = 0.0002; P = 0004) than whole milk and colostrum FTH1. These results indicate that FTH1 is enriched in the milk-derived EVs and suggest that EVs play a predominant role in the FTH1 delivery mechanism for the piglet. The extent to which FTH1 in EVs accounts for the overall iron delivery mechanism in piglets is yet to be determined. [ABSTRACT FROM AUTHOR]

Our previous study found dietary konjac flour (KF) supplementation could improve insulin sensitivity and reproductive performance of sows, but its high price limits its application in actual production. This study aimed to investigate the effects of supplementation of a cheaper combined dietary fiber (CDF, using bamboo shoots fiber and alginate fiber to partially replace KF) from the last 50 days of gestation to parturition on farrowing performance, insulin sensitivity, gut microbiota, and placental function of gilts. Specifically, a total of 135 pregnant gilts with a similar farrowing time were blocked by backfat thickness and body weight on day 65 of gestation (G65d) and assigned to 1 of the 3 dietary treatment groups (n = 45 per group): basal diet (CON), basal diet supplemented with 2% KF or 2% CDF (CDF containing 15% KF, 60% bamboo shoots fiber, and 25% alginate fiber), respectively. The litter performance, insulin sensitivity and glucose tolerance parameters, placental vessel density, and short-chain fatty acids (SCFAs) levels in feces were assessed. The gut microbiota population in gilts during gestation was also assessed by 16S rDNA gene sequencing. Compared with CON, both KF and CDF treatments not only increased the piglet birth weight (P < 0.05) and piglet vitality (P < 0.01) but also decreased the proportion of piglets with birth weight ≤ 1.2 kg (P < 0.01) and increased the proportion of piglets with birth weight ≥ 1.5 kg (P < 0.01). In addition, KF or CDF supplementation reduced fasting blood insulin level (P < 0.05), homeostasis model assessment-insulin resistance (P < 0.05), serum hemoglobin A1c (P < 0.05), and the level of advanced glycation end products (P < 0.05) at G110d, and increased the placental vascular density (P < 0.05) at farrowing. Meanwhile, KF or CDF supplementation increased microbial diversity (P < 0.05) and SCFAs levels (P < 0.05) in feces at G110d. Notably, the production cost per live-born piglet was lower in CDF group (¥ 36.1) than KF group (¥ 41.3). Overall, KF or CDF supplementation from G65d to farrowing could improve the farrowing performance of gilts possibly by improving insulin sensitivity, regulating gut microbiota and metabolites, and increasing placental vascular density, with higher economic benefits and a similar effect for CDF vs. KF, suggesting the potential of CDF as a cheaper alternative to KF in actual production. [ABSTRACT FROM AUTHOR]

Consumption of zearalenone (ZEN) detrimentally affects tissues and systems throughout the body, and these deleterious effects are especially pronounced in swine. The objectives of this project were to determine the effects of short-term consumption of ZEN (at concentrations that could be found on-farm) on growth, carcass weight, liver weight, and reproductive tissues of pubertal gilts, and to determine if the effects are transient or persistent. Cross-bred gilts (107.25 ± 2.69 kg) were randomly assigned to one of three feed treatments: 1) solvent only for 21 d (CON; n = 10), 2) ZEN for 7 d followed by 14 d of solvent (ZEN-7; 6 mg/d; n = 10), and 3) ZEN for 21 d (ZEN-21; 6 mg/d; n = 10). Body weights were collected at the beginning and end of the experiment (189.1 ± 0.8 and 211.1 ± 0.8 d of age, respectively). Carcass weights and tissues were collected at harvest. There were no treatment-based differences in growth, carcass, liver, or reproductive tissue weights. Histological analyses revealed differences based on treatment and the interaction between treatment and luteal status. The thickness of the ampullary muscularis declined with ZEN exposure (P < 0.05), while the isthmic epithelial cell height (P < 0.01) and uterine endometrial thickness (P < 0.02) increased. Interestingly, the thickness of the isthmic muscularis, uterine myometrium, and epithelial cell height only differed in the presence of a corpus luteum. Uterine epithelial cell height in the luteal phase was lowest in ZEN-7 pigs (P < 0.01). The isthmic muscularis in the luteal phase was thinner in pigs from both ZEN treatments (P < 0.01). Conversely, the luteal-stage myometrium was thicker in pigs from both ZEN treatments (P < 0.01). The discovery of these tissue-based differences during the luteal phase is particularly concerning since this corresponds with the time when embryos would be affected by the functional competency of the oviduct and uterus. The results of this work demonstrate that short-term consumption of ZEN produces microscopic, but not macroscopic alterations in reproductive organs which are likely to have negative effects on their subsequent function and that these differences persist even after ZEN consumption ceases. Taken together, these results indicate that it is insufficient to rely solely on outwardly visible symptoms as indicators of zearalenone exposure, as detrimental effects on reproductive tissues were found in the absence of phenotypic and morphologic changes. [ABSTRACT FROM AUTHOR]

Post-weaning fertility failures occur more often in parity 1 (P1) sows due to high metabolic demands for lactation and their inability to meet energy requirements for maintenance, growth, and reproduction. We hypothesized that body condition loss occurs more frequently in P1 sows nursing a large litter, resulting in impairment of ovarian follicle development during lactation and post-weaning, which can negatively impact estrus and subsequent fertility. At 24 h post-farrowing, P1 sows (n = 123) were assigned to treatment (TRT) based on sow weight and the number of functional teats to receive a high number (HN, 15 to 16) or low number (LN, 12) of nursing piglets. At weaning, sows in each TRT were assigned to receive PG600 or None (Control). During lactation, sow body measures were obtained and ovarian follicles were assessed in mid-lactation and post-weaning. Lactation data were analyzed for the effects of TRT, and fertility data after weaning were assessed for TRT x PG600, but there were no interactions (P > 0.10). During lactation, 22.2 % of HN sows lost ≥ 4 piglets due to death or removal, and so these sows were excluded from further analysis. The HN sows were lighter (−6.2 kg), had less backfat (−1.0 mm), had lower body condition score (−0.4), and lost more nursing piglets (−1.2) than LN sows (P < 0.05). However, HN sows weaned more pigs (14.0) than LN sows (11.0). There was no effect of TRT on wean to estrus interval (4.2 d), but the interval was 0.5 days shorter for PG600 (P = 0.004) than control. There were no effects of TRT or PG600 on estrus within seven days after weaning (87.3 %), but PG600 induced smaller (P = 0.002) follicles at estrus (6.7 mm) than control (7.3 mm). In the subsequent parity, there were no effects of TRT or PG600 on farrowing rate (93.9%) and total born (13.2). Overall, HN sows lost more piglets and body condition but still weaned more pigs without any detrimental effects on subsequent reproductive performance. [ABSTRACT FROM AUTHOR]

Eighty-eight gilts [initial body weight (BW) 49.8 ± 0.8 kg] were recruited to determine the effects of moderate energy and protein restriction during the development period on changes in BW and backfat depth (BF) and subsequent lactation performance. Gilts were randomly assigned to one of four feeding programs: 1) standard commercial diet fed ad libitum (CON), 2) standard commercial diet fed 10% or 3) 20% below ad libitum, or 4) a high–fiber diet fed ad libitum [2.5 times more fiber (neutral detergent fiber) than the commercial diet to dilute net energy and crude protein by approximately 20% and 13%, respectively; FIB ]. The gilts were housed individually and received the feeding programs between 90 and 190 (breeding) d of age and standard gestation and lactation diets thereafter. Litters were standardized to 12 ± 1 pigs within 48 h of farrowing; weaning occurred at 20.0 ± 0.4 d of age. Gilts that received the 20% restricted program had lower overall average daily feed intake (ADFI) during the development period (2.64 ± 0.04 kg; P < 0.05) versus all other feeding programs and gilts that received the 10% restricted program had lower ADFI than FIB and CON, which were not different (2.96 vs. 3.44 and 3.47 ± 0.04 kg for 10%, FIB and CON, respectively; P < 0.05). Plasma free fatty acid (FFA) concentrations on day 180 of age were lower for gilts that received the 10% and 20% restricted programs compared to gilts that received the FIB and CON programs, which were not different (97 and 86 vs. 220 and 149 ± 29 µEq/L, respectively; P < 0.05). Plasma concentrations of glucose, urea, prolactin, and IGF-1 were not different among feeding programs on day 180 of age. At breeding, gilts that received the FIB and 10% programs had lower BW and BF versus CON (145.7 and 144.8 vs. 155.2 ± 0.9 kg and 14.4 and 14.8 vs. 16.5 ± 0.2 mm for BW and BF, respectively; P < 0.05) but greater BW than gilts that received the 20% restricted program (137.9 kg; P < 0.05). The BW and BF of gilts did not differ at the end of gestation or at weaning. The ADFI of sows during lactation and offspring birth weight and growth rate during lactation and the 5-wk nursery period were not influenced by gilt development feeding program. Therefore, a high-fiber feeding program could be used in group-housing gilt-development scenarios, where feed is offered ad libitum, to control BW and BF prior to breeding without influencing milk production in the subsequent lactation period. [ABSTRACT FROM AUTHOR]

This study determined the effects of dietary supplementation with creatine to gestating gilts (n = 6) on their ability to form guanidinoacetate (GA) and creatine in placentae and maternal tissues. Gilts were assigned randomly to one of two dietary groups: control and creatine supplementation (Cr; n = 12 gilts/ diet). Once estrus was detected (d 0), gilts were artificially inseminated 12 h and 24 h later. All gilts were individually housed and fed 0.9 kg of a corn- and soybean-based diet containing 14% crude protein (but no creatine or GA) twice daily. Gilts in the control and Cr groups received daily top dressing of 0 or 2 × 15 g Cr either between d 10 and 60 or between d 10 and 90 of gestation. There were 6 gilts per dietary treatment per gestational stage. On either d 60 or 90 of gestation, gilts were euthanized to collect maternal tissues and placentae. Each tissue (~150 mg) was incubated at 37 ℃ for 2 h in 2 mL of oxygenated (95% O2 /5% CO2 ) Krebs bicarbonate buffer with or without a) 2 mM glycine plus 2 mM L-arginine or b) 0.2 mM GA plus 0.5 mM L-methionine (the source of S-adenosylmethionine). After the 2-h period of incubation, 0.2 mL of 1.5 M HClO4 was added to the medium. The acidified medium plus tissue was homogenized and the homogenizer rinsed with 1 mL water, followed by the addition of 0.1 mLl of 2 M K2CO3. The extract was analyzed for GA, creatine, and amino acids using HPLC. Results indicated that on both d 60 and 90 of gestation, a) GA was formed from glycine plus L-arginine by maternal kidneys and pancreas of all gilts, but not maternal liver, placentae, or endometria; b) GA was converted into Cr by both maternal liver and pancreas, but not maternal kidneys, endometria, or placentae; c) dietary supplementation with Cr did not affect (P > 0.05) either the formation of GA from glycine plus L-arginine in maternal kidneys and pancreas or the conversion of GA into creatine in maternal liver and pancreas (Tables 1 and 2). Collectively, these results indicate interorgan cooperation to form creatine in pregnant gilts to support fetal growth and development, as well as the lack of inhibition of this metabolic pathway by dietary supplementation with creatine. [ABSTRACT FROM AUTHOR]

Environmental heat stress (HS) can impair muscle mitochondrial function which may contribute to negative health outcomes, but little is known about potential treatments to rescue mitochondrial function during HS. To test the hypothesis that thyroid hormone (T3) would protect mitochondrial function during HS, samples were collected from the right ventricle (RV) of 3-mo-old, crossbred gilts under 4 different environmental conditions: thermoneutral (TN; 22°C; n = 8); 1 d HS (HS1; 38°C; n = 7); oral supplementation of 1.33 μg kg body weight (BW)-1. d-1 Cytomel (liothyronine sodium) during the 1 d HS (HS1TH; n = 8); and 7 d HS (HS7; n = 8). The oxidative portion of the semitendinosus (ST) was also collected from all groups plus a 5th group: oral supplementation of Cytomel during 7 d HS (HS7TH, n = 8). Mitochondrial volume density was estimated by citrate synthase (CS) activity, and oxidative phosphorylation (OP) and electron transfer (E) capacities were determined via high resolution respirometry. Data were analyzed using mixed linear models in SAS v9.4 with treatment group as a fixed effect and pig (treatment) as a random effect. Within the RV, the contribution of OP supported by complex I (PCI) to maximal E was less in HS1TH gilts compared with all other groups (P ≤ 0.02), and the contribution of E supported by complex II (ECII) to maximal E was greater in TN than HS1 or HS7 (P ≤ 0.02) and tended to be greater in TN compared with HS1TH gilts (P = 0.07). Within the ST, integrative (relative to tissue wet weight) PCI was greatest in TN gilts (vs. HS7 and HS7TH, P ≤ 0.0002; vs. HS1 and HS1TH, P ≤ 0.06) and least in HS7 and HS7TH (vs. HS1 and HS1TH, P ≤ 0.05). Integrative maximal P (PCI+II) was greatest in TN pigs (compared with HS1TH, HS7, and HS7TH, P ≤ 0.05; compared with HS1, P = 0.09). Integrative maximal E (ECI+II) was also greatest in TN gilts than all other groups (P ≤ 0.05) while ECII was greater in TN pigs compared with HS7 and HS7TH (P ≤ 0.009) and tended to be greater than HS1 and HS1TH (P ≤ 0.09). In ST, intrinsic (relative to CS activity) PCI and PCI+II were greater in TN compared with HS1, HS1TH, and HS7 pigs (P ≤ 0.03) and PCI+II tended to be greater in TN than HS7TH (P ≤ 0.06). Intrinsic ECI+II and ECII were greater in TN compared with all other treatment groups (P ≤ 0.04). These results suggest that T3 supplementation did not protect mitochondrial function from negative impacts of HS in skeletal muscle but may have modified electron transfer through complex I in cardiac muscle which may have implications on oxidative stress. [ABSTRACT FROM AUTHOR]

In modern swine production, most of the sows are housed in a cage system in the farrowing unit. Although this system is intended to reduce preweaning mortality, the welfare of the sow might be compromised as it greatly restricts their natural behavior. Free farrowing systems allow sows to move around in the farrowing pen, which might stimulate their nesting behavior, shorten the farrowing duration and improve locomotion score, therefore, optimizing the longevity of the sows. However, the risk of increased preweaning mortality in free farrowing systems is greater compared with cage systems. Previous studies suggested that sow behavior, also known as mothering ability, can influence preweaning mortality as an increased level of posture changes could lead to increased mortality. With grunts, a sow could initiate the suckling of the piglets but also terminate it by hiding her udder from the piglets. However, there is conflicting evidence on what characteristics of maternal ability are correlated with piglet mortality, and most studies relied on limited manual observations, which might be biased. Using computer vision algorithms, the behavior and the movement pattern of a large number of sows could be monitored at a high density and on a continuous basis. Hence, this study intended to investigate the mothering ability of sows in free farrowing systems based on large quantities and unbiased observations using computer vision. Forty cameras were installed above free farrowing pens to observe the behavior of the sow. The dataset is continuously growing and will add data of 8 sows every week, totaling 416 sows on a yearly basis. The performance of the sows and their piglets are recorded, including body weight (BW), backfat, total number born, number weaned, birth weight, and weaning weight. Computer vision algorithms (YOLO) will be trained to estimate the contour and posture of the sow and the position of the piglets. Preliminary results based on a small subset of animals showed that the algorithm is able to detect the sows and their postures accurately, and it is now being extended to detect piglet locations. This will allow us to find beneficial behavior of sow and piglets, estimate genetic parameters for potential implementation in breeding programs, and eventually improve sow performance in a welfare-friendly free farrowing system. [ABSTRACT FROM AUTHOR]

Transition from the sow to nursery pens is a stressful time for pigs and commonly leads to postweaning anorexia and growth check. This can have negative impacts on pig health, welfare, and lifetime performance. The objective of this study was to test the relationship between enrichment use and feeder use immediately post-weaning on final nursery pig body weight (BW). At arrival, 29 mixed-sex pigs (Camborough 1050 X 337, PIC), 19 to 24d of age, were randomly sorted into 3 pens (~0.29 m2/pig) at the Iowa State University Swine Nutrition Farm. Each pen was equipped with a 4-hole, dry self-feeder measuring 0.6 m long. Each pen had two enrichment devices, consisting of one cotton rope and two biscuits, suspended from the feeder at pig height. Biscuits were replaced daily. Total number of interactions with the enrichment and feeder were collected at the individual pig level. All pigs were continually observed for two 1 h periods (h 1 and the h 6 after biscuit replacement) each day over wk 1 (d 0 – d 6). A pig was considered interacting with enrichment if its snout contacted the rope or enrichment biscuit. A pig was considered interacting with the feeder if 1) its head was over the feeder tray, and 2) its nose down in the feeder. Both enrichment and feeder interactions were considered terminated if the pig ceased active interaction for 3 s or more. Behaviors were summed together by time period and day for each pig. Individual BW were taken at the end of the 42-d nursery study. After the nursery trial was completed, the 29 pigs were allocated to a light BW treatment (n = 14) and a heavy BW treatment (n = 15) using the final average BW (24.22 kg) of the. Pigs with a final BW lighter than the group average were assigned to the light treatment, while pigs with a heavier BW than average were assigned to the heavy treatment. T-tests were conducted for enrichment and feeder interactions by final BW group and the pig was the experimental unit. A P ≤ 0.05 was considered significant. There were no observed differences between final pig body weight treatments and the enrichment and feeder interactions over the first week of nursery (P ≤ 0.87). Numerically, there were more overall enrichment interactions than feeder interactions for both BW treatments over wk 1 (Table 1). In conclusion, this enrichment device was of biological interest to the pigs, but other factors impact feeder usage in the first week and need to be considered in future work. [ABSTRACT FROM AUTHOR]

Primiparous sows (n = 50) were used to evaluate the impacts of increasing standardized ileal digestible (SID) Lys-to-net energy (NE) ratios on sow performance and nitrogen utilization during a 24-d lactation period. Sows were assigned to one of five diets with equally spaced and increasing SID Lys-to-NE ratios between 2.85 and 5.51 g SID Lys/ Mcal NE. Desired ratios were achieved by blending the two extreme diets in varying proportions using a feeding system with feed blending capabilities and were provided to sows immediately after farrowing until weaning (d 24 ± 0.3). Litters were standardized to 13 ± 1 piglets within 24 h after birth and were not provided creep feed. Nitrogen balances were conducted between d 4 and 7 (NB1), 12 and 15 (NB2), and 20 and 23 (NB3) of lactation, with total urine collection and fecal grab sampling. Contrast statements were used to assess linear and quadratic effects of increasing the SID Lysto- NE ratio. Linear (LBL) and quadratic broken-line and polynomial quadratic models were used to determine the optimum dietary Lys-to-NE ratios for maternal nitrogen retention. The Bayesian information criterion was used to assess best fit. Sow body weight (BW) and backfat depth losses over lactation decreased with increasing dietary SID Lys-to-NE ratio (linear; -19.0 to -5.9 ± 3.7 kg, P = 0.001 and -3.9 to -2.0 ± 0.7 mm, P = 0.003, respectively). No differences were observed for milk nitrogen output (69.3 ± 4.5, 74.2 ± 6.6, 85.6 ± 6.8 g/day for NB1, NB2, and NB3, respectively), overall piglet average daily gain (219 ± 10 g), and piglet BW at weaning (6.33 ± 0.24 kg). Sow average daily feed intake was not influenced by SID Lys-to-NE ratio (5.3 ± 0.2 kg/day) but sow nitrogen intake (linear; P < 0.001) and total nitrogen excretion (urine + feces; linear; P < 0.001) increased with dietary SID Lys-to-NE ratio in all NB periods. Nitrogen retention (linear; P < 0.001) and maternal nitrogen retention (nitrogen intake – nitrogen excretion – milk nitrogen output; P < 0.05) increased with dietary SID Lys-to-NE ratio in all NB periods (-22.8 to -2.7 ± 6.7, 3.6 to 36.3 ± 8.4, and 9.0 to 34.8 ± 6.8 g/d for maternal nitrogen retention in NB1, NB2, and NB3, respectively). The LBL model showed that maternal nitrogen retention was optimized beyond the SID Lys-to-NE ratio limits in NB1 but breakpoints were observed for maternal nitrogen retention at 4.74 and 4.85 g SID Lys/Mcal NE in NB2 and NB3, respectively. Therefore, optimizing the SID Lys-to-NE ratio during specific weeks of lactation could minimize maternal nitrogen losses of primiparous sows. [ABSTRACT FROM AUTHOR]

Objectives were to determine the effects of reducing dietary nutrient density after the second dose of GnRF immunization (Improvest; Zoetis Inc.) on growth performance and carcass characteristics. Pigs (n = 1,008) were fed in five diet phases during the 102-d grow-finish period. Diets were formulated to meet 100% of recommended SID Lys to net energy established by PIC (2021) for physically castrated (PC) barrows/ non-immunized gilts (regular diet), while diets for GnRF-immunized pigs were formulated with 120% SID lysine than PC barrows/ non-immunized gilts (nutrient-dense diet). During diet phase-4 (2 d after the second GnRF analogue dose), SID lysine and vitamins/ trace minerals for the nutrient-dense diet were either maintained at 100% or reduced to 95% or 90%. During diet phase-5 (18 d after second GnRF analogue dose), SID lysine and vitamins/trace minerals nutrientdense diet were either maintained at 100% or reduced to 90% or 80%. The study consisted of six pen replications (21 pigs/pen) of the following eight treatments: CON-NEG: traditional mixed-sex pigs (PC barrows and non-immunized gilts) that received the regular diet; CON-POS: traditional mixed-sex pigs that received the nutrient-dense diet; I-MALE-100: immunized males (I-MALES) that received the nutrient-dense diet with 100% density; I-MALE-95/90: I-MALES that received the nutrient-dense diet with 95% density during diet phase-4 and 90% density during diet phase- 5; I-MALE-90/80 I-MALES that received the nutrientdense diet with 90% density during diet phase-4 and 80% density during diet phase-5; I-FEM-100: immunized females (I-FEM) that received the nutrient-dense diet with 100% density; I-FEM-95/90: I-FEM that received the nutrient-dense diet with 95% density during diet phase-4 and 90% density during diet phase-5; I-FEM-90/80: I-FEM that received the nutrient-dense diet with 90% density during diet phase-4 and 80% density during diet phase-5. Data were analyzed with PROC MIXED of SAS, with pen serving as the experimental unit. In addition, linear effects of diet dilution for I-MALE and I-FEM pigs were tested using contrast statements. There were not significant linear effects of diet dilution for gain:feed or hot carcass weight in either the I-MALE (P > 0.28) or I-FEM (P > 0.78) pigs. For the overall period, gain:feed was improved by 7.4% for I-MALE pigs compared with the CONNEG pigs and was improved by 1.6% for the I-FEM pigs compared with the CON-NEG pigs. Hot carcass weight was 3.6 kg greater for the I-MALE pigs compared with the CON-NEG pigs and 1.6 kg greater for the I-FEM pigs compared with the CON-NEG pigs. The results would suggest that removing nutrients during the post-second dose period of GnRF immunization does not negatively affect growth performance or carcass characteristics, while both I-MALE and I-FEM pigs are more efficient and heavier when compared with traditional mixed sex pigs. [ABSTRACT FROM AUTHOR]

The practical application of embryo transfer in pigs could benefit from using embryo donors for multiple cycles. Thus, raising the need to investigate feeding strategies for donors which will not be required to recover body condition lost during previous lactation. The objective was to evaluate the effects of temporary feed restriction, from d 6 to 14 of the estrous cycle, on growth, blood variables and reproductive performance in replacement gilts. Replacement gilts (n = 20; TN70, Topigs Norsvin, Oak Bluff, Canada) were assigned equally across 2 feeding regimens following a randomized complete block design where the block was backfat thickness. The feeding regimens were based on the first day of the estrous cycle: CON, recommended feeding levels from d 0 to 14 and a flush feeding (25% above recommended levels) from d 15 until d 21; or RES, CON but with restricted feeding (25% below recommended levels) from d 6 to 14. The CON treatment was based on the recommendations of the Feed Manual TN70 (Topigs Norsvin, 2015). On d 0, 5, 14 and 20 of the cycle, body weight and backfat thickness were measured. On d 21 (detected estrus), gilts were inseminated and on d 27 they were euthanized to collect embryos, ovaries and uterus. The uterus and ovaries were weighed whereas corpora lutea were counted and weighed. Blood serum was collected on d 14, and 20 for chemical analyses. Data were analyzed using the mixed procedure of SAS where each gilt was the experimental unit. Feeding regimens were considered as the fixed effect and backfat block as the random effect. Means were obtained with the LSMEANS statement. No differences (P > 0.05) were observed on growth performance among feeding regimens. However, when comparing the average daily gain (ADG) within feeding regimens between feeding periods, no differences (P > 0.05) were observed among gilts fed CON whereas gilts fed RES showed a decreased (P < 0.05) ADG during d 6 to 14 compared with d 0 to 5 and d 15 to 21. Regarding blood serum variables, gilts fed RES had greater (P < 0.05) total protein and potassium but less (P < 0.05) sodium-to-potassium ratio than gilts fed CON on d 14. On d 20, Gilts fed RES had greater (P < 0.05) cholesterol values than gilts fed CON. No differences (P > 0.05) were observed on the number of corpora lutea, number of embryos collected or on collection efficiency. Similarly, no differences (P > 0.05) were observed on the weight of reproductive organs or on measurements of ovaries among feeding regimens. In conclusion, restricting feed intake of replacement gilts by 25% of the recommendation from d 6 to 14 of the estrous cycle reduced ADG without compromising their reproductive performance. [ABSTRACT FROM AUTHOR]

4-hydroxy-L-proline (Hyp) is an abundant amino acid in the collagen of pigs. The turnover of this protein releases a large amount of Hyp, traditionally considered a metabolic waste. However, results of recent studies documented the conversion of Hyp into glycine in young pigs. Because pregnant gilts are typically fed a soybean meal-based diet that contains insufficient glycine and provides only 35% of the total glycine needed by pregnant gilts, it is possible that the conceptus can form glycine from Hyp. This hypothesis was tested in the present study. Gilts were fed a 1.8-kg corn- and soybean meal-based diet containing 14% crude protein. On d 90 of gestation, gilts (n = 5) were hysterectomized after euthanasia. Slices (~ 100 mg) of placentae or endometria were incubated at 37 °C for 2 h in oxygenated (95% O2/5% CO2) Krebs-Henseleit bicarbonate buffer (pH 7.4, with 5 mM D-glucose) containing 0 or 2 mM Hyp. After a period of 2 h incubation, 200 μL of 1.5 M HClO4 was added into the incubation medium to stop the reaction. The tissues were homogenized and rinsed with 1 mL water, followed by the addition of 100 μL of 2 M K²CO³. The neutralized extract was analyzed for amino acids using HPLC involving derivatization with o-phthaldialdehyde. Tissues that received no incubation time were determined as well. Data were analyzed by the paired t-test. Results indicated that glycine was produced from 2 mM Hyp by the placenta (Table 1). Glycine was subsequently converted into serine by the placenta. The formation of glycine and serine from Hyp was not due to protein breakdown because there were no differences (P > 0.05) in concentrations of tyrosine (an amino acid that is neither synthesized nor degraded by porcine placentae) in the incubation medium plus tissue at the end of a 2-h incubation period. In contrast to placentae, endometria did not form glycine or serine from Hyp. These findings indicate an important role for Hyp in the provision of both glycine and serine in the conceptus, which may be nutritionally and physiologically significant to compensate for a deficiency of glycine in maternal diets for gestating gilts. (Supported by a USDA/NIFA grant # 2022-67015-36376 and USDA multistate Hatch project #7752: S1081) [ABSTRACT FROM AUTHOR]

Gilts [n = 90; initial body weight (BW) = 189.1 ± 3.9 kg] were used to determine the effect of feeding a yeast additive (Saccharomyces cerevisiae inactivated through hydrolyzation; HY) to gestating and lactating gilts and/or the offspring during the nursery period on lifetime offspring growth performance. Gilts were randomly assigned to one of three dietary treatments (n = 30/treatment): standard gestation and lactation diets (GHY0) or supplemented with 0.25% (GHY0.25) or 1% (GHY1.0) HY. Diets were fed between d 85 of gestation until weaning at d 21 (2.6 kg/d in gestation, ad libitum in lactation). At weaning, 8 piglets/litter were placed in nursery pens and pens were randomly assigned to a control (NO) or a HY-supplemented diet (NHY), apart from GHY1.0 offspring who were only provided NO during the nursery period (n = 12). In nursery phases 1, 2 and 3, HY was included at 0.75, 0.50, and 0.25% respectively. Thereafter, pigs received standard grower and finisher rations until slaughter (160 d of age). Data were analyzed in SAS using GLIMMIX with gilt treatment as the main effect (pre-weaning); post-weaning performance used gilt and nursery treatments as the main effects, and interactive effects were tested separately due to the incomplete 3 × 2 factorial design. Mean comparisons were conducted using the Tukey-Kramer test to separate LSmeans. Gilt BW was unaffected by gilt treatment, but gilts fed GHY1.0 had greater total lactation feed intake versus GHY0.25 (128.6 vs. 109.4 ± 7.7 kg; P < 0.01). At birth, GHY0.25 offspring were 70 g heavier than pigs from GHY0 (P < 0.001) with GHY1.0 intermediate. At weaning, GHY0.25 and GHY1.0 offspring were heavier than GHY0 offspring (5.9 vs. 5.6 kg; P < 0.001). After weaning, neither gilt nor nursery diet influenced offspring BW. Pigs fed GHY1.0-NO had greater ADFI versus all other treatments in the nursery (interaction; P < 0.001), GHY0.25-NHY had greater ADFI than GHY0.25-NO and GHY1.0-NO in the grower (interaction; P = 0.005), and NHY consumed more feed than NO in the finisher phase (main effect; P < 0.001). In the nursery, NHY had less average daily feed intake (ADFI) than NO (main effect; P < 0.05), but in grower and finisher, NHY had greater ADFI than NO pigs (main effect; P < 0.001). In the nursery, gain to feed (G:F) was greater for GHY0-NHY versus GHY0.25-NHY and GHY1.0-NO, and greater for GHY0-NO versus GHY0.25-NHY with all other treatments intermediate (interaction; P < 0.05). In the grower phase, G:F was unaffected by maternal or nursery diet, but in the finisher phase, G:F was less for pigs fed NHY versus NO during the nursery phase (main effect; P < 0.05). Slaughter BW, hot carcass weight, and fat and lean percents were not influenced by gilt or nursery diet. Therefore, HY provided to gilts during gestation and lactation, improved pre-weaning offspring growth, but HY supplemented to pigs during the nursery period had greater positive effects on lifetime growth performance. [ABSTRACT FROM AUTHOR]

Feed used for maintenance in sows is around 1% of their live weight, and a 10 kg greater sow body weight (BW) from first lifetime insemination onwards requires 36.5 kg extra feed for maintenance annually, which increases the feed cost for a 1,000-sow operation unit by approximately $15,000 CAD per year. Genetic selection, through emphasis on feed efficiency, changes body development year after year. Phenotypic sow development should allow for adequate litter weight, litter size and longevity for an optimum lifetime production. In this study we wanted to understand sow mature weight and its variation. Sow BW (n = 14,554 of 5,292 sows) around farrowing and litter weights were collected on two crossbred and one purebred farm with industry accepted feeding protocols; that is, limited feeding at the different stages of production. Sow BW were corrected for stage of gestation and realized litter weights to represent empty BW at the day of farrowing. Body weight at the age of first insemination was added. When estimating genetic parameters, the statistical model for sow BW included, in addition to Line and HerdYearSeason, a rate parameter as a covariate (b1 *AGE -1) within Farm. A bivariate analysis applying a repeatability model for the BW of purebred and crossbred animals yielded similar heritabilities (h² = 0.58 ± 0.05 and h2 = 0.55 ± 0.05, for purebred and crossbred, respectively), and greater relevant genetic variances (335 ± 40 and 166 ± 13 kg² ) with a clearly positive, but not significant genetic correlation of 0.49 ± 0.46. The (random) effect of a permanent environment was not significant for either characteristic. A second analysis in which genetic parameters were estimated simultaneously for the plateau and the rate parameter showed that genetic selection based on the repeatability model for BW only, affected both the plateau and the rate parameter. Only crossbreds were included in this analysis because the minimum required BW observations per sow were not met for purebred animals. Selection for mature BW might affect other key traits. The phenotypic correlations between the EBVs for the BW of crossbred sows and litter weight, litter size and longevity were -0.15, -0.02 and +0.02, respectively. Genetically heavier or smaller animals do not have better production with heavier ones possibly having slightly decreased performance. However, if animals are treated as equally and uniformly as possible, it is reasonable to assume that genetically heavier animals use more feed for growth, instead of for reproduction, given equal feeding rations. Heritability estimates point to a clear genetic drive to BW development. This study shows the relevance of weight observations at nucleus level and the necessity to estimate genetic correlations with production traits. [ABSTRACT FROM AUTHOR]

The objective was to determine the genetic factors influencing mobility traits recorded from 5 mo-old gilts. Mobility was measured using a pressuresensing mat (GAIT4) and 7 d of video recorded activity (NUtrack). Gilts (n = 3,659) were evaluated for the study, but only 2,172 gilts had data for both systems. GAIT4 system creates a series of measurements for each foot related to pressure, duration and step length of each foot generating a lameness score for each foot. Traits studied summarized values for all 4 feet: average stride length, average stance time, standard deviation of stance time, lameness score and total scaled pressure. NUtrack measurements were rotations, velocity, and distance walked as well as the time spent eating, sitting, standing, lying sternal and lying lateral. All NUtrack traits were standardized to a mean of zero and standard deviation of 1.0 based on each pen-day subgroup. Mixed model analyses were conducted in R fitting animal as a random effect and fixed effects of breed of sire and contemporary group, with day included for NUtrack data. ssGBLUP analyses were conducted in WOMBAT using animal effects from R models as phenotypes. Three generations of pedigree were included and genotypic data from the NeoGen Porcine 50K beadchip on 3,186 animals representing 60% of gilts with NUtrack data, 67% of gilts with GAIT4 data and most parents (>99%). Single trait analyses were conducted for all traits, gEBVs estimated and then SNP effects estimated by back-solving equations. Significance values were determined by 5,000 permutations and a Bonferroni adjustment factor applied. Estimates of heritability ranged from 0.08 to 0.41 and traits from the NUtrack system tended to have greater heritability than GAIT4 traits. There were 343 significant SNP effects in 39 unique chromosomal regions. There were 133 significant SNP associations located on chromosome 14 between 45-47 Mb associated with rotations, distance and times standing and lying. Pathway analysis identified proteoglycan and apelin pathways to be over-represented based on associations with SNP located at 2:45, 2:51, 13:79 and 14:40 (SSC:Mb). Proteoglycans are a subunit of cartilage and apelins affect blood flow and angiogenesis which make them candidates for the development of osteochondrosis, a leading cause of lameness in pigs. These results will facilitate selection of more robust animals capable of withstanding commercial production environments and group sow housing. USDA is an equal opportunity employer. [ABSTRACT FROM AUTHOR]

Poor outcomes reflect low performance during the farrowing and lactation periods and unanticipated sow removals. Since the period around farrowing has the highest risk for sow health issues, monitoring of sows in that time-period will improve both welfare and productivity. The aim of this study was to identify the most relevant risk factors for predicting poor outcomes and the implication for sow welfare. Identifying these factors could potentially enable management interventions to decrease incidences of compromised welfare or poor performance. Data from 1,103 sows sourced from two nucleus herds were recorded for a range of variables investigated as potential predictors of poor outcomes in the farrowing house. Poor outcomes (scored as binary traits) reflected three categories in a sow’s lifecycle: farrowing, lactation, and removals. Univariate logistic regression was used to identify predictors in the first instance. Predictors from univariate analyses were subsequently considered together in multi-variate models. The least square means representing predicted probabilities of poor outcomes were then reported on the observed scale. Several predictors were significant across two different environments (farms) and for all three categories. These predictors included feed refusal (lack of appetite), crate fit, locomotion score, and respiration rate. Normal appetite compared to feed refusals reduced the risk of farrowing failure (13.5 vs. 22.2%, P = 0.025) and removals (10.4 vs. 20.4%, P < 0.001). Fit in the crate was significant (P < 0.001) for farrowing and lactation outcomes, and was more informative than parity. Sows with sufficient space had two to three times reduced risk of poor outcomes compared to restrictive crates relative to sow dimensions. Sows with good locomotion score pre-farrowing had two to three times less risk of farrowing failure (P = 0.025) and reduced piglet mortality (P < 0.001), weaned two piglets more relative to affected sows (P < 0.001), and were less likely to be removed before weaning (3.24 vs. 12.3%, P = 0.014). Sows with higher respiration rates had a significantly (P < 0.001) reduced risk of poor farrowing outcomes. This study demonstrated it is possible to predict poor outcomes for sows prior to farrowing, suggesting there are opportunities to decrease the risk of poor outcomes and increase overall sow welfare. [ABSTRACT FROM AUTHOR]

Our previous study found that dietary nucleotide supplementation, including adenosine 5ʹ-monophosphate (AMP), could increase AMP content in sow milk and promote piglet growth, but its effects on placental efficiency and piglet vitality remain unknown. This experiment aimed to investigate the effects of dietary AMP or its metabolite adenosine (ADO) supplementation on sow reproductive performance and placental angiogenesis. A total of 135 sows with a similar farrowing time were blocked by backfat and body weight (BW) at day 65 of gestation and assigned to one of three dietary treatment groups (n = 45 per treatment): basal diet, basal diet supplemented with 0.1% AMP or 0.1% ADO, respectively. Placental analysis and the characteristics of sows and piglets unveiled that compared with control (CON) group, AMP or ADO supplementation could improve sow placental efficiency (P < 0.05) and newborn piglet vitality (P < 0.05), increase piglet birth weight (P < 0.05), and reduce stillbirth rate (P < 0.05). More importantly, AMP or ADO supplementation could increase the contents of AMP, ADO, and their metabolites in placentae (P < 0.05). Meanwhile, AMP or ADO supplementation could also increase placental vascular density (P < 0.05) and the expression of vascular endothelial growth factor A (P < 0.05), as well as promote the migration and tube formation of porcine iliac artery endothelial cells (P < 0.05). Overall, maternal dietary AMP or ADO supplementation could increase their contents in the placenta, thereby improving placental angiogenesis and neonatal piglet vitality. [ABSTRACT FROM AUTHOR]

Precision feeding (PF) aims to provide the right amount of nutrients at the right time for each animal. Lactating sows generally receive the same diet, which either results in insufficient supply and body reserve mobilization, or excessive supply and high nutrient excretion. With the help of online measuring devices, computational methods, and smart feeders, we introduced the first PF decision support system (DSS) for lactating sows. Precision (PRE) and conventional (STD) feeding strategies were compared in commercial conditions. Every day each PRE sow received a tailored ration that had been computed by the DSS. This ration was obtained by blending a diet with a high AA and mineral content (13.00 g/kg SID Lys, 4.50 g/kg digestible P) and a diet low in AAs and minerals (6.50 g/kg SID Lys, 2.90 g/kg digestible P). All STD sows received a conventional diet (10.08 g/kg SID Lys, 3.78 g/kg digestible P). Before the trial, the DSS was fitted to farm performance for the prediction of piglet average daily gain (PADG) and sow daily feed intake (DFI), with data from 1,691 and 3,712 lactations, respectively. Sow and litter performance were analyzed for the effect of feeding strategy with ANOVA, with results considered statistically significant when P < 0.05. The experiment involved 239 PRE and 240 STD sows. DFI was similarly high in both treatments (PRE: 6.59, STD: 6.45 kg/d; P = 0.11). Litter growth was high (PRE: 2.96, STD: 3.06 kg/d), although it decreased slightly by about 3% in PRE compared to STD treatments (P < 0.05). Sow body weight loss was low, although it was slightly higher in PRE sows (7.7 vs. 2.1 kg, P < 0.001), which might be due to insufficient AA supply in some sows. Weaning to estrus interval (5.6 d) did not differ. In PRE sows SID Lys intake (PRE: 7.7, STD: 10.0 g/kg; P < 0.001) and digestible P intake (PRE: 3.2, STD: 3.8 g/kg; P < 0.001) declined by 23% and 14%, respectively, and feed cost decreased by 12%. For PRE sows, excretion of N and P decreased by 28% and 42%, respectively. According to these results, PF appears to be a very promising strategy for lactating sows. [ABSTRACT FROM AUTHOR]

Feeding probiotics like live yeast Saccharomyces cerevisiae var. boulardii (SB) in pig diets has been suggested to preserve health and reduce antibiotic use during critical periods like weaning. This study was conducted to determine whether SB added to the diet of sows during the last 2 mo of gestation and the 4 wk of lactation may contribute to support the health and performance of piglets before and after weaning through changes in sow physiology, milk composition, and fecal microbiota. Crossbred sows (n = 45) from parity 1 to 9 were allocated to two dietary treatments: Control (n = 23) and SB (n = 22). Sows in the SB group were fed the same standard gestation and then lactation diet as the Control sows but with the addition of SB at 1 × 109 colony-forming units/kg of feed. Piglets were weaned under challenging conditions consisting of mixing of litters, no pen cleaning, and a 2-h period of nonoptimal temperature exposure. Blood and feces were collected from sows on days 28 and 113 of gestation and days 6 (feces only) and 28 of lactation, and from piglets on days 6 (feces) and 28 of lactation and day 5 after weaning. Colostrum was collected during parturition and milk on day 6 of lactation. Supplementation of sow diets with SB influenced the fecal microbiota of the sows and their piglets. Five days after weaning, the alpha-diversity was lower (P < 0.05) in piglets from SB sows than in piglets from Control sows. Analysis of microbiota with partial least square discriminant analysis discriminated feces from SB sows from that of Control sows at 110 d of gestation (29.4% error rate). Piglet feces could also be discriminated according to the diet of their mother, with a better discrimination early after birth (day 6 of lactation) than after weaning (day 5 postweaning, 3.4% vs. 12.7% error rate). Five days after weaning, piglets had greater white blood cell count, plasma haptoglobin concentration, and oxidative stress than before weaning (P < 0.001). Nevertheless, SB supplementation in sow diets had no effect (P > 0.05) on most of health criteria measured in blood and growth performance of piglets during lactation and the postweaning period. Moreover, dietary supplementation of SB to sows did not elicit any changes (P > 0.05) in their reproductive performance, metabolic and health status, nor in the concentration of immunoglobulins and nutrients in colostrum and milk. In the present experimental conditions, feeding SB to sows influenced sow and piglet microbiota with no consequences on their health and performance. [ABSTRACT FROM AUTHOR]

Heat stress (HS) compromises almost every aspect of animal agriculture including reproduction. In pigs, this infecundity is referred to as seasonal infertility (SI), a phenotype including ovarian dysfunction. In multiple species, HS-induced hyperprolactinemia has been described; hence, our study objectives were to characterize and compare HS effects on circulating prolactin (PRL) and ovarian Janus kinase/signal transducer and activator of transcription (JAK-STAT) signaling during the follicular (FOL) or luteal (LUT) phases of the estrous cycle in postpubertal gilts. Gilts were estrus synchronized using altrenogest and environmental treatments began immediately after altrenogest withdrawal. For the FOL study: postpubertal gilts were allocated to constant thermoneutral (TN ; n = 6; 20 ± 1.2 °C) or cyclical HS (n = 6; 25 to 32 ± 1.2 °C) conditions for 5 d. In the LUT study: postpubertal gilts were assigned to either TN (n = 7; 20 ± 2.6 °C) or cyclical HS (n = 7; 32 to 35 ± 2.6 °C) conditions from 2 to 12 days postestrus (dpe). Blood was collected by jugular venipuncture for PRL quantification on day 5 in the FOL and on day 0 and day 12 in the LUT gilts. Ovaries and corpora lutea (CL) were obtained from euthanized FOL and LUT gilts on day 5 and day 12, respectively. Western blotting was performed to quantify prolactin receptor (PRLR) and JAK/STAT pathway protein abundance. In the FOL phase, no difference (P = 0.20) in circulating PRL between thermal groups was observed. There was no effect (P ≥ 0.34) of HS on PRLR, signal transducer and activator of transcription 3 (STAT3), signal transducer and activator of transcription 5α (STAT5α), and phosphorylated signal transducer and activator of transcription α/β tyrosine 694/699 (pSTAT5α/β Tyr694/699 ) abundance and Janus kinase 2 (JAK2), phosphorylated janus kinase 2 tyrosine 1007/1008 (pJAK2 Tyr1007/1008 ), STAT1, phosphorylated signal transducer and activator of transcription 1 tyrosine 701 (pSTAT1 Tyr701 ), phosphorylated signal transducer and activator of transcription 1 serine 727 (pSTAT1 Ser727 ), and phosphorylated signal transducer and activator of transcription 3 tyrosine 705 (pSTAT3 Tyr705 ) were undetectable in FOL gilt ovaries. Ovarian pSTAT5α/βTyr694/699 abundance tended to moderately increase (4%; P = 0.07) in FOL gilts by HS. In the LUT phase, circulating PRL increased progressively from 2 to 12 dpe, but no thermal treatment-induced difference (P = 0.37) was noted. There was no effect (P ≥ 0.16) of HS on CL abundance of PRLR, pJAK2Tyr1007/1008, JAK2, STAT1, pSTAT1Tyr701, pSTAT1Ser727, pSTAT3Tyr705, STAT5α, or pSTAT5α/βTyr694/699. In LUT phase, CL STAT3 abundance was increased (11%; P < 0.03) by HS. There was no impact of HS (P ≥ 0.76) on levels of pJAK2Tyr1007/1008 and pSTAT5α/βTyr694/699 in LUT gilts; however, the CL pSTAT3Tyr705:STAT3 ratio tended to be decreased (P = 0.10) due to HS. These results indicate an HS-induced estrous cycle-stage-dependent effect on the ovarian JAK/STAT pathway, establishing a potential role for this signaling pathway as a potential contributor to SI. [ABSTRACT FROM AUTHOR]

In livestock, mortality in general, and mortality of the young, is societal worries and is economically relevant for farm efficiency. Genetic change is cumulative; if it exists for survival of the young and genetic merit can be estimated with sufficient accuracy, it can help alleviate the pressure of mortality. Lack of survival is a moving target; livestock production is in continuous change and labor shortage is a given. There is now ample evidence of clear genetic variance and of models able to provide genomic predictions with enough accuracy for selection response. Underlying traits such as birth weight, uniformity in birth weight, gestation length, number of teats, and farrowing duration all show genetic variation and support selection for survival or, alternatively, be selected for on their own merit. [ABSTRACT FROM AUTHOR]

Mixed parity sows (n = 3,451; PIC, Hendersonville, TN; parities 2 through 9) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. Our hypothesis, like observed in earlier research, was that increasing linoleic acid (LA) and α-linolenic acid (ALA) would improve sow and litter performance. At approximately day 112 of gestation, sows were randomly assigned within parity groups to 1 of 4 corn–soybean meal–wheat-based lactation diets that contained 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low LA and ALA in diets with CWG or high LA and ALA in diets that included soybean oil. Sows received their assigned EFA treatments until weaning and were then fed a common gestation and lactation diet in the subsequent reproductive cycle. Average daily feed intake during the lactation period increased (P < 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. However, daily LA and ALA intakes of sows fed the Combination and SO diets were still greater (P < 0.05) than those of sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P < 0.05) piglet weaning weights and greater (P < 0.05) litter ADG when compared with litters from sows fed diets with CWG that provided low EFA. Despite advantages in growth performance, there was no impact of sow EFA intake on piglet survivability (P > 0.10). Additionally, lactation diet EFA composition did not influence sow colostrum or milk dry matter, crude protein, or crude fat content (P > 0.10). However, LA and ALA content in colostrum and milk increased (P < 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P > 0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by soybean oil during lactation increased overall litter growth and pig weaning weights, reduced sow ADFI, but did not affect piglet survivability or subsequent performance of sows. [ABSTRACT FROM AUTHOR]

The physiology during late gestation and the transition period to lactation changes dramatically in the sow, especially during the latter period. Understanding the physiological processes and how they change dynamically as the sow approaches farrowing, nest building, giving birth to piglets, and producing colostrum is important because these processes greatly affect sow productivity. Glucose originating from assimilated starch accounts for the majority of dietary energy, and around farrowing, various organs and peripheral tissues compete for plasma glucose, which may become depleted. Indeed, physical activity increases shortly prior to farrowing, leading to glucose use by muscles. Approximately ½ to 1 d later, glucose is also needed for uterine contractions to expel the piglets and for the mammary gland to produce lactose and fat for colostrum. At farrowing, the sow appears to prioritize glucose to the mammary gland above the uterus, whereby insufficient dietary energy may compromise the farrowing process. At this time, energy metabolism in the uterus shifts dramatically from relying mainly on the oxidation of glucogenic energy substrates (primarily glucose) to ketogenic energy supplied from triglycerides. The rapid growth of mammary tissue occurs in the last third of gestation, and it accelerates as the sow approaches farrowing. In the last 1 to 2 wk prepartum, some fat may be produced in the mammary glands and stored to be secreted in either colostrum or transient milk. During the first 6 h after the onset of farrowing, the uptake of glucose and lactate by the mammary glands roughly doubles. Lactate is supplying approximately 15% of the glucogenic carbon taken up by the mammary glands and originates from the strong uterine contractions. Thereafter, the mammary uptake of glucose and lactate declines, which suggests that the amount of colostrum secreted starts to decrease at that time. Optimal nutrition of sows during late gestation and the transition period should focus on mammary development, farrowing performance, and colostrum production. The birth weight of piglets seems to be only slightly responsive to maternal nutrition in gilts; on the other hand, sows will counterbalance insufficient feed or nutrient intake by increasing mobilization of their body reserves. Ensuring sufficient energy to sows around farrowing is crucial and may be achieved via adequate feed supply, at least three daily meals, high dietary fiber content, and extra supplementation of energy. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to determine the impact of various combinations of yeast-based direct fed microbials (DFM) in diets fed to nursery pigs weaned from sows fed lactation diets with or without yeast additives. In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs. yeast additives) and nursery diets with or without added yeast-based DFM on growth performance and antimicrobial resistance (AMR) patterns of fecal Escherichia coli. Treatments were arranged in a 2 × 2 factorial with main effects of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+ and 0.025% SafMannan, Phileo by Lesaffre, Milwaukee, WI) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+, 0.05% SafMannan, and 0.05% NucleoSaf from days 0 to 7, then concentrations were decreased by 50% from days 7 to 24) with 5 pigs per pen and 17 replications per treatment. Progeny from sows fed yeast additives had increased (P < 0.05) average daily gain (ADG) from days 0 to 24 and days 0 to 45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased days 0 to 45 ADG (P = 0.079). Fecal E. coli isolated from pigs from the sows fed yeast group had increased (P = 0.034) resistance to nalidixic acid and a tendency for increased resistance to ciprofloxacin (P = 0.065) and gentamicin (P = 0.054). Yet, when yeast additives were added in the nursery, there was reduced (P < 0.05) fecal E. coli resistance to azithromycin and chloramphenicol. In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with two different combinations of DFM on growth performance. Treatments were arranged in a 2 × 3 factorial with main effects of sow treatment (same as described in Exp. 1) and nursery treatment (control; YCW, 0.05% of SafMannan from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24; or DFM, 0.10% MicroSaf-S from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24) with 6 pigs per pen and 8 to 10 replications per treatment. From days 0 to 10 post-weaning, progeny of sows fed yeast additives had increased (P < 0.05) ADG and G:F. In conclusion, feeding sows yeast through lactation improved offspring growth performance in the nursery. Although feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1, feeding DFM improved growth later in the nursery period in Exp. 2. [ABSTRACT FROM AUTHOR]

A total of 80 sows (Line 241; DNA, Columbus, NE) across three farrowing groups were used in a study to evaluate the effect of feeding live yeast and yeast extracts to lactating sows on sow and litter performance and antimicrobial resistance (AMR) patterns of sow fecal E. coli. Sows were blocked by farrowing group, BW, and parity on day 110 of gestation and allotted to 1 of 2 dietary treatments. Dietary treatments consisted of a standard lactation diet with or without yeast-based pre- and probiotics (0.10% Actisaf Sc 47 HR+ and 0.025% SafMannan; Phileo by Lesaffre, Milwaukee, WI). Diets were fed from day 110 of gestation until weaning (approximately d 19 post-farrow). A tendency (P = 0.073) was observed for increased feed intake through lactation when sows were fed a diet with yeast additives compared with the control diet. There was no evidence (P > 0.10) that treatment influenced any other sow or litter performance measurements. Fecal samples were collected upon entry into the farrowing house and at weaning from the first farrowing group (27 sows) to determine the resistance patterns of E. coli. E. coli was isolated from fecal samples and species confirmed by PCR detection of uidA and clpB genes. Microbroth dilution method was used to determine the minimal inhibitory concentrations (MIC) of E. coli isolates to 14 antimicrobials. Isolates were categorized as either susceptible, intermediate, or resistant based on Clinical and Laboratory Standards Institute guidelines. An interaction (P = 0.026) of diet × sampling day was observed for cefoxitin where fecal E. coli showed no evidence of treatment differences (P = 0.237) in MIC values at entry, but sows fed the control diet had lower (P = 0.035) MIC values at weaning compared with sows fed yeast additives. There were no diet main effects (P > 0.10) on the resistance of fecal E. coli. There was an increased (P < 0.02) toward resistance for 11 of the 14 antimicrobials over time. Fecal E. coli were resistant to tetracycline and ceftriaxone at weaning. Fecal E. coli were susceptible or intermediate in all sampling days to the remaining antimicrobials. In conclusion, feeding live yeast and yeast extracts tended to increase feed intake during lactation but did not influence either sow or litter performance measurements or the resistance of fecal E. coli during lactation except for cefoxitin, which had a higher MIC at the end of lactation when yeast additives were present in the diet. [ABSTRACT FROM AUTHOR]

The effect of long-term administration of two Bacillus strains was tested on 98 breeding sows and their litters allotted into three treatments: a control group (CON); supplemented with 5 × 108 cfu/kg B. subtilis − 541 (BSU); or with 5 × 108 cfu/kg B. amyloliquefaciens − 516 (BAM). Reproductive and performance variables were recorded over three cycles with 56 dams remaining through the third lactation. Blood and fecal samples were taken longitudinally from 12 sows per treatment on days 8 and 21 of the third lactation and milk samples were taken on day 21. Feces from one piglet per litter was sampled on days 21 and 33 and jejunal gene expression was assessed in two piglets on day 21. Changes in fecal microbiota were assessed by 16S rRNA gene sequencing (Illumina MiSeq) and gene expression by Open-Array technology. Metabolomic responses were analyzed in milk by NMR and Ig-G and Ig-A specific antibodies were determined by ELISA. No significant differences were observed on feed intake, body weight, or fat mobilization of the sows. However, a significant increase in the total number of piglets born was observed in supplemented sows. Although the increase was seen from the first cycle with BAM, improvements were not seen with BSU until the third cycle. BAM also increased the number of born-alive and weaned piglets. NMR analysis showed an impact of BAM on milk composition. No differences were found in milk or blood immunoglobulins. A different structure of the fecal microbiota was found in supplemented sows, with changes across phylum, family, and genus. These changes were greater at day 8, suggesting a relevant role of probiotics establishing a new intestinal balance after labor. Shifts in the microbiota were also seen in the piglets, with a clearer impact post-weaning than in suckling. In this regard, correlations between microbial groups of sows and piglets showed a higher link with weaned (d33) than with suckling pigs (d21), reinforcing the idea of an early maternal carry-over. No changes due to treatment in jejunal gene expression were detected; however, piglet size had a clear impact on different genes. In summary, the addition of both probiotics, and particularly Bacillus amyloliquefaciens , demonstrated potential benefits on the prolificacy of sows. Daily feeding of Bacillus amyloliquefaciens resulted in an increase in the number of weaned piglets. The high correlations between the compositions of the microbiota of sows and their piglets are evidence of maternal imprinting, with effects lasting beyond weaning. [ABSTRACT FROM AUTHOR]

Methods for developing incoming replacement gilts can indirectly and directly influence survivability of their offspring. Indirectly, having proper gilt development reduces culling rates and mortality, which increases longevity and creates a more mature sow herd. Older sows are more likely to have greater immunity than gilts and therefore can pass this along to their pigs in both quantity and quality of colostrum and milk, thus improving piglet survivability. Directly, proper gilt development will maximize mammary gland development which increases colostrum and milk production leading to large, healthy pig. As for the developing gilt at birth, increasing colostrum intake, reducing nursing pressure, providing adequate space allowance, and good growth rate can increase the likelihood that gilts successfully enter and remain in the herd. Light birth weight gilts (<1 kg) or gilts from litters with low birth weight should be removed early in the selection process. Gilts should be weaned at 24 d of age or older and then can be grown in a variety of ways as long as lifetime growth rate is over 600 g/d. Current genetic lines with exceptional growth rate run the risk of being bred too heavy, reducing longevity. On the other hand, restricting feed intake at specific times could be detrimental to mammary development. In these situations, reducing diet amino acid concentration and allowing ad libitum feed is a possible strategy. Gilts should be bred between 135 and 160 kg and at second estrus or later while in a positive metabolic state to increase lifetime productivity and longevity in the herd. Once bred, gilts should be fed to maintain or build body reserves without becoming over-conditioned at farrowing. Proper body condition at farrowing impacts the percentage of pigs born alive as well as colostrum and milk production, and consequently, offspring performance and survivability. Combined with the benefit in pig immunity conferred by an older sow parity structure, gilt development has lasting impacts on offspring performance and survivability. [ABSTRACT FROM AUTHOR]

The goal of this project was to determine if standardized ileal digestible (SID) lysine provided at 40% above estimated requirements, with the concomitant increase in protein intake, from days 90 to 110 of gestation would stimulate mammary development in gilts. From day 90 of gestation, Yorkshire × Landrace gilts were fed 2.65 kg of either a conventional diet (CTL , control, n = 19) providing 18.6 g/d of SID Lys or a diet providing 26.0 g/d of SID Lys via additional soybean meal (HILYS , n = 19). Both diets were isoenergetic. Jugular blood samples obtained on days 90 and 110 of gestation were used to measure concentrations of insulin-like growth factor-1 (IGF-1), metabolites, and amino acids (AA). Gilts were necropsied on day 110 ± 1 of gestation to obtain mammary glands for compositional analyses, immunohistochemistry, and analysis of mRNA abundance for AA transporters and markers of cell proliferation and differentiation. The HILYS gilts gained more body weight (P < 0.01) during the experimental period compared with CTL gilts, and had greater fetal weights (1.29 vs. 1.21 ± 0.03 kg, P < 0.05). There was no difference in circulating IGF-1, glucose, or albumin (P > 0.10) between HILYS and CTL gilts on day 110 of gestation, whereas concentrations of urea and free fatty acids were greater (P < 0.01), and those of Trp and Ala were lower (P < 0.05), in HILYS than CTL gilts. The provision of lysine at 40% above estimated requirements increased total mammary parenchymal mass by 44%, as well as total parenchymal fat, protein, DNA, and RNA (P < 0.01). The mRNA abundance of ACACA was greater (P < 0.05) in HILYS than CTL gilts, while only the AA transporter SLC6A14 tended (P < 0.10) to be greater. Results demonstrate that providing dietary Lys above current National Research Council recommendations in late gestation increases mammary development in gilts. Results also indicate that Lys may have been limiting for protein retention. These data suggest that the use of a two-phase feeding strategy during gestation, whereby dietary Lys is increased from day 90, could benefit potential sow milk yield in the subsequent lactation. [ABSTRACT FROM AUTHOR]

Energy demands during lactation greatly influence sow body condition and piglet performance. We hypothesized that primiparous sows or sows with reduced body condition would produce piglets with reduced growth and delayed sexual maturation. Eight weekly farrowing seasons were used to evaluate sow body condition (post-farrowing, PF and weaning, WN) and piglet growth from 157 dams. Body condition was measured at PF and WN using sow calipers (last rib and hip) and 10th rib ultrasound. Sows were categorized as thin, moderate, or fat by caliper (PF or WN). Individual pig weights were recorded on approximately 1, 10, WN, 45, 100, and 145 d of age. At 100 and 145 d of age, 10th-rib backfat and loin eye area were measured on 567 pigs and first estrus was monitored in 176 gilts reserved for breeding selection beginning at approximately 170 d of age. Sows had similar (P > 0.10) PF last rib caliper measurements but at WN, first parity sows had the smallest caliper measurements compared to other parities (P < 0.05). Parities 1, 2, and 3 sows had similar (P > 0.10) loin eye area at PF; however, at WN first parity sows had the smallest loin eye area (P < 0.05; 38.2 ± 0.63 cm2). Parity 1 sows had the greatest (P < 0.05) reduction of backfat and loin eye area over the lactation period (−2.9 ± 0.31 mm and −2.6 ± 0.49 cm2, respectively). At 1 d of age and WN, piglets from first parity sows weighed the least (P < 0.05) but were the heaviest (P < 0.05) at 100 and 145 d of age. Pigs from first parity litters had larger (P < 0.05) loin eye area at 100 and 145 d of age and greater backfat (P < 0.05) at 145 d of age. Fat sows at WN (last rib or hip) had the lightest (P < 0.05) piglets at 10 d of age and WN. However, at 45 d of age, piglets from fat sows (last rib or hip) were heavier (P < 0.05) than piglets from moderate and thin sows. Tenth rib backfat at 100 and 145 d of age tended (P < 0.10) to be less in pigs reared by thin sows (PF and WN hip). Tenth rib loin eye area was similar among pigs reared by fat, moderate, or thin sows. Gilts developed in litters from fourth parity sows had (P < 0.05) delayed age at puberty in contrast to gilts from first or third parity sows (200.9 ± 4.96 d vs. 189.0 ± 2.29 d and 187.5 ± 2.84 d, respectively). Although progeny body weights were typically less from first parity dams through 45 d of age, these progeny were similar or heavier at 100 and 145 d of age in contrast to progeny from other parities. Furthermore, gilt progeny from first parity dams did not have delayed pubertal attainment. [ABSTRACT FROM AUTHOR]

Heat stress (HS) decreases lactation output in sows due to an attempt to reduce metabolic heat production. However, this negatively affects litter growth performance. Therefore, the study objective was to determine whether electronically controlled cooling pads (ECP) would improve indirect measures of lactation output (e.g., total heat production [THP]) and litter growth performance in HS exposed sows. Over two repetitions, 12 multiparous (2.69 ± 0.85) lactating sows (265.4 ± 26.1 kg body weight [BW]) and litters were assigned to either an ECP (n = 3/repetition) or a non-functional ECP (NECP; n = 3/repetition) and placed into farrowing crates within indirect calorimeters from days 3.7 ± 0.5 to 18.7 ± 0.5 of lactation. Litters were standardized across all sows (11.4 ± 0.7 piglets/litter), and sows were provided ad libitum feed and water. All sows were exposed to cyclical HS (28.27 ± 0.26 °C nighttime to 33.09 ± 0.19°C daytime). On days 4, 8, 14, and 18 of lactation, indirect calorimetry was performed on each individual sow and litter to determine THP and THP/kg BW0.75. Body temperature (TB) was measured hourly using vaginal implants, and respiration rate (RR; breaths per minute [bpm]) was measured daily at 0700, 1100, 1300, 1500, and 1900 h. Sow feed intake (FI) was assessed daily. Litter weights were obtained at birth, on days 4, 8, 14, and 18 of lactation, and at weaning. Data were analyzed using PROC GLIMMIX with sow and/or litter as the experimental unit. An overall decrease (P < 0.01; 25 bpm) in RR and maximum daily TB (P = 0.02; 0.40 °C) was observed in ECP vs. NECP sows. An increase in THP (P < 0.01; 20.4%) and THP/kg BW0.75 (P < 0.01; 23.1%) was observed for ECP when compared with NECP sows and litters. Litter average daily gain and weaning weight were increased (P < 0.05; 25.0 and 19.2%, respectively) for ECP vs. NECP litters. No FI differences were observed (P = 0.40) when comparing ECP (5.66 ± 0.31 kg/d) and NECP (5.28 ± 0.31 kg/d) sows. In summary, ECPs improve litter growth, thermoregulatory measures, and bioenergetic parameters associated with greater milk production in lactating sows exposed to cyclical HS. [ABSTRACT FROM AUTHOR]

Longevity and reproductive performance are economically important traits in the swine industry that are largely influenced by nutrition and other environmental factors. Reproductive performance and longevity through 4 parities was assessed in gilts of 2 genetic lines developed on ad libitum access to feed or restricted to 75% of ad libitum intake. A total of 661 gilts were used in a 2 × 2 factorial with half of the gilts allocated to an ad libitum diet (AL; n = 330), while the other half were energy restricted by 25% (R; n = 331) from 123 to 235 d of age. All gilts were sired by an industry maternal line. Dams of the gilts were from either a Large White (W) by Landrace (L) industry maternal line or Nebraska Selection Line 45X, producing gilts designated as W × L (n = 355) and L45X (n = 306), respectively. Daily estrus detection began at 140 d of age to obtain age at puberty (AP). Gilts (n = 510) were mated on their second or later estrus, beginning at 240 d of age. Sow weight and backfat were recorded at 110 d of gestation and weaning of each parity. Number of live-born, stillborn, and mummified pigs per litter and piglet birth and weaning weights were recorded through 4 parities. More L45X than W × L and more AL than R gilts reached puberty by 230 d of age (P < 0.01). Dietary treatment did not affect probability to produce parities 1 to 4 or any litter trait analyzed. The L45X females tended to be more likely to produce parities 1 (P < 0.08) and 3 (P < 0.06), while W × L had heavier litters at birth (P < 0.01) and weaning (P = 0.01). Treatment by parity interactions (P < 0.01) existed for weight and backfat prior to farrowing and backfat at weaning, and weight at weaning exhibited a line by treatment by parity interaction (P = 0.04) as R sows had lower weights and backfats in earlier parities, but caught up to AL sows in later parities. A treatment by parity interaction (P < 0.01) was also present for backfat loss from farrowing to weaning as R gilts lost less backfat than AL in parities 1 and 2, but more in parities 3 and 4. No significant differences were detected between lines or treatments for lifetime production traits. The populations of pigs and data presented here provide a framework for a diverse array of further studies. Alternative approaches to restrict energy have been assessed in addition to methods of marker-assisted and genomic selection for improvement of litter size and sow longevity. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the reliability of using Ca to P ratio measured in spot urine samples to assess P intake adequacy in gestating and lactating sows. A total of 36 sows were fed one of six concentrations of dietary total P (0.40, 0.48, 0.56, 0.64, 0.72, 0.80%) from day 7.5 + 1 after breeding until the end of lactation (day 26.6 + 1). Dietary Ca to P ratio was maintained constant across treatments at 1.25. Total 24-hour urine samples were collected in mid and late gestation (days 77.1 + 2 and 112.4 + 1), and early and late lactation (days 4.5 + 1 and 18.2 + 1). In parallel to 24-hour collections, spot urine samples were collected at three different times (early morning, late morning, and late afternoon) in late gestation and late lactation. Urine Ca and P concentrations were measured and Ca to P ratio was calculated. Sows were classified as P-adequate or P-deficient according to dietary P intake. Urine Ca to P ratio was greater in sows fed P-deficient diets than sows fed P-adequate diets (P < 0.001). Receiver operator characteristic (ROC) curves were used to determine the cut-off values for urine Ca to P ratio to predict P intake adequacy. Three different categories of P intake were defined according to urine Ca to P ratio: deficient, adequate, and excessive. The area under the ROC for Ca to P ratio was 0.88 (95% CI 0.81 – 0.95). Best cut-off value of urine Ca to P ratio was 1.5 (sensitivity 94% and specificity 68%) to identify sows fed P-deficient diets and 0.5 for P-excessive diets (sensitivity 82% and specificity 82%). A strong relationship between Ca to P ratio in 24-hour and spot urine samples was determined (r = 0.93, P < 0.01), independent of physiological state and collection time of spot samples (adjusted-R 2 = 0.86, P < 0.01). The degree of agreement between spot and 24-hour urine for P intake adequacy, assessed by Cohen's weighted kappa analysis, was substantial (0.78, 95% CI 0.69 – 0.88). We conclude that urinary Ca to P ratio provides a reliable prediction of the adequacy of P intake in reproducing sows. Urinary Ca to P ratio measurements in random spot urinary offers a practical method to determine dietary P adequacy. [ABSTRACT FROM AUTHOR]