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Genetic selection for improved feed efficiency and lean growth in pigs has resulted in reduced intramuscular fat content. The aim of this study was to evaluate growth performance, carcass traits, and meat quality in genetically lean immunocastrated pigs grouped based on divergent Warner-Bratzler Shear Force (WBSF) values. The WBSF values of the longissimus lumborum (LL) muscle were obtained from a previous trial evaluating 4 diets, 6 replicates per diet, and 3 pigs per pen, summing up to 72 Large White immunocastrated male pigs. Pigs (initial BW = 28.44 ± 2.95 kg) were fed diets containing either 1.5% soybean oil (CON) or 3% soybean oil (SO), canola oil (CO), or fish oil (FO) in a 98-d study. The original dataset was used to segregate pigs into 2 treatments: high (5.4 to 4.3 kg) and low (3.8 to 2.8 kg) WBSF. The SO diet did not show extreme values for WBSF and was not included in the resulting dataset, which comprised 2 treatments (high- and low-WBSF), 3 blocks (CON, CO, and FO), and 6 replicates per treatment (12 experimental units). No significant differences were observed for growth performance between WBSF groups. When compared with low-WBSF pigs, high-WBSF pigs tended to have decreased (P = 0.07) backfat thickness and intramuscular fat content in the LL and greater (P = 0.09) carcass lean percentage and cooking losses. Oleic acid concentration was less (P = 0.05) in the LL intramuscular fat of high-than low-WBSF pigs. There were statistical tendencies for decreased (P = 0.06) total monounsaturated fatty acids and increased (P = 0.09) total polyunsaturated fatty acids concentrations in the LL intramuscular fat of high-than low-WBSF pigs. In conclusion, immunocastrated male pigs with tender meat had improved nutritional attributes of pork, with no effects on feed efficiency and carcass traits. [ABSTRACT FROM AUTHOR]

An approach to the development of the economically optimal dietary concentration of Paylean, duration of the Paylean feeding, and dietary lysine concentration for finishing hog production is presented. A simulation model describing daily growth of hogs under different Paylean and lysine concentration combinations was adapted for optimizing nutrition and marketing when feed is supplemented with Paylean. Net returns per pig space per day under four alternative payment schemes are maximized based on 10-year average price levels and production costs. Profitability of Paylean is investigated, and management strategies for swine production with Paylean are developed for two representative finishing operations. [ABSTRACT FROM AUTHOR]

Lactating sows are especially sensitive to heat stress (HS) due to high metabolic demands resulting from milk output. Therefore, there is a need to develop effective cooling technologies that reduce the impact of HS on lactating sows. The study objective was to determine whether electronically controlled cooling pads (ECP) would allow sows to remain euthermic under HS conditions. Twelve multiparous (2.69 ± 0.85) lactating sows (265.4 ± 26.1 kg) and litters (11.4 ± 0.7 piglets/litter) were assigned to either a non-functional ECP (NECP; n = 6) or an ECP (n = 6), housed in farrowing crates, and tested over two repetitions. Sows were provided feed and water ad libitum and all sows were exposed to HS (28.27 ± 1.42°C nighttime to 35.14 ± 0.70°C daytime). Body temperature (TB), was measured hourly using vaginal implants, and respiration rate (RR) was measured in 30 min intervals from 0600 to 2100 hrs over 2 d representing mid- and late lactation. Mixed model periodic regression equations were fitted to the TB and RR to time. The final model for TB included the effect of replicate, random effect of sow, day of lactation as a covariate, single-phase sine and cosine variables for each treatment and 2-phase sine and cosine periodic regression variables. The final model for RR included the random effect of sow, effect of treatment, replicate, day of lactation, sleeping, and single-phase sine and cosine functions for each treatment. An interaction (P < 0.05) between treatment and sine or cosine was observed for TB. For RR there was no interaction for treatment and cosine (P = 0.07), but an interaction (P < 0.05; -9.94) was observed for sine. The significant treatment by wavelength interactions observed indicate a change in RR and TB patterns when sows are placed on ECPs. [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., metabolic heat production) and litter growth performance in HS exposed sows. Over two repetitions, 12 multiparous (2.69 ± 0.85) lactating sows (265.4 ± 26.1 kg) and litters were assigned to either an ECP (n = 6) or a non-functional ECP (NECP; n = 6) and placed into farrowing crates within indirect calorimeters from d 3.7 ± 0.5 to d 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 ± 1.42°C nighttime to 35.14 ± 0.70°C daytime). On d 4, 8, 14, and 18 of lactation, indirect calorimetry was performed on each individual sow and litter to determine total heat production (THP). Body temperature (TB), was measured hourly using vaginal implants, and respiration rate (RR) was measured daily at 0700, 1100, 1300, 1500, and 1900 h. Litter weights were obtained at birth and weaning. An overall decrease (P < 0.01; 25 bpm) in RR and maximum daily TB (P = 0.02; 0.40°C) was observed in ECP versus NECP sows. An increase in THP (P < 0.01; 20.4%) and THP/kg0.75 (P < 0.01; 23.1%) was observed for ECP when compared to NECP sows and litters. Litter growth rate was increased (P < 0.01; 20.8%) in ECP versus NECP sows. In summary, the use of ECP improves litter growth, thermoregulatory measures, and bioenergetic parameters associated with greater milk production in lactating sows exposed to cyclical heat stress. [ABSTRACT FROM AUTHOR]

Genetic selection for health and welfare-related traits is paramount in livestock breeding. Piglet allergic responses to soybean protein negatively impact animal growth and welfare. The objectives of this study were to estimate the heritability of soybean allergic responses and genetic correlations between soybean and peanut allergies (r1,2) in divergently-selected pig lines. The base population consisted of nine sire lines (primarily Yorkshire and Landrace) and two dam sources (Yorkshire × Chester White-F1 and Landrace × Yorkshire-F1). Soybean and peanut-allergic responses were measured through a skin test (0-6 scale; 0-no allergic responses; 6-severe allergic responses; characterized by wheal and flair) on pigs fed a diet containing soybean meal for 21 d post-weaning. A total of 5,505 animals from nine generations of two contrasting lines (i.e., high and low skin test reaction) were included in the analyses. The statistical model included contemporary group, breeding lines, replication, sex, and weaning weight (linear covariate) as fixed effects (P-value < 0.05), and additive genetic, maternal genetic, and maternal permanent environment as random effects. Threshold and linear Bayesian models were used to estimate genetic parameters, using a pedigreebased relationship matrix containing 9,201 animals. The heritability estimates for the general soybean allergic response were 0.199 ± 0.045 and 0.119 ± 0.025 for the threshold (liability scale) and linear models, respectively, suggesting that soybean allergic responses are heritable and can be improved through selective breeding. A weak negative genetic correlation between allergic responses and birth weight was observed (r1,2 = -0.253 ± 0.192), which shows that the genetic variance of soybean allergy is less dependent on birth weight. However, a high positive genetic correlation was estimated between soybean and peanut-allergic responses (r1,2 = 0.89 ± 0.048), which indicates a potential cross-reactivity of soybean and peanut allergies. Our findings suggest that it is possible to reduce food allergy responses in pigs through selective breeding. [ABSTRACT FROM AUTHOR]

Heat stress (HS) decreases semen quality and production in boars. Therefore, the study objective was to evaluate the use of electronically-controlled cooling pads to reduce the negative effects of HS on semen quality. Boars (n=24) were randomly allotted to two treatment groups: boars housed on a non-functional cooling pad (CON) or pads flushing water every 8 minutes or when the pad reached 28.5°C (FLUSH). For 3 d, boars were subjected to cyclical HS (28 to 32°C; >50% relative humidity). Semen was collected for 7 weeks (2 weeks prior to determine baseline semen parameters, the day after HS, and weekly for 4 weeks post HS), and evaluated for volume, sperm concentration, motility, progressive motility, morphology, viability, and kinematic motion parameters. FLUSH boars had higher semen volumes compared to CON (P=0.011) without a corresponding increase in total sperm produced (P=0.852). Boars in FLUSH had higher motility in all weeks (87.0-90.8%) when compared to CON boars. FLUSH boars had higher motility starting in week 4 after HS compared to CON (P=0.017). No differences in progressive motility or kinematic motion parameters were found. There was a tendency for FLUSH boars to have a higher percent normal morphology compared to CON boars (83.1 vs 77.5%, P=0.083) resulting from decreased proximal and distal droplets in the FLUSH boars (P=0.029 and P=.0014, respectively). During week 2 post HS, there was a tendency for FLUSH boars to have a lower percentage of non-viable cells compared to all other weeks for FLUSH and CON boars (P=0.088). Cooling pads were effective at reducing the negative impacts of HS on semen volume, motility, and morphological abnormalities. [ABSTRACT FROM AUTHOR]

Dacitic tuff breccia (DTB) and poultry by-products (PBP) were added to nursery pig diets to evaluate their effects on growth performance in a 35 d experiment. A randomized complete block design based on BW and sex was used. Newly weaned pigs (N=564, 20.1 d of age, 6.18±0.006 kg initial BW) allotted to four diets (15 replicates/treatment; 9 or 10 pigs/pen): 1) Negative control (NC; no DTB or PBP), 2) NC+DTB (0.5% inclusion), 3) NC+PBP (4% chicken by-product meal + 2% feather meal - replacing fishmeal, corn, and synthetic amino acids in the NC), 4) NC+DTB+PBP. Phase 1-3 were each 7-d and Phase 4 was from d21-35. During week one there were no differences (P >0.10) among treatments. In week 2, pigs fed DTB tended to increase ADG (323 vs. 303 g/d; P=0.068) and ADFI (376 vs. 356 g/d; P=0.055) compared to pigs not fed DTB and pigs fed PBP tended to have increased ADG (P=0.093). In week 3 pigs fed PBP had reduced ADG (460 vs 483 g/d; P=0.011) and G:F (0.689 vs. 0.723; P< 0.001), and there tended to be an interaction for G:F (P=0.083) with DTB improving G:F when fed in combination with PBP but reducing G:F in the control diet. In week 4, feeding PBP decreased ADG (384 vs 415 g/d; P< 0.01) and ADFI (629 vs 666 g/d; P< 0.01) compared to pigs fed no PBP. There were no differences among treatments during week 5. For Phase 4 (d21-35) pigs fed PBP had decreased ADG (479 vs 497 g/d; P=0.041) and tended to have reduced ADFI (P=0.092) compared to pigs fed no PBP. Overall (d 0-35), there were no significant differences among treatments. In conclusion, DTB improved nursery pig growth performance early, however, pigs fed PBP had decreased ADG and feed efficiency late in the nursery period. [ABSTRACT FROM AUTHOR]

Lactating sows (N=140, York x Landrace) were used to evaluate the effects of a liquid prototype (LIQP) and dry (XPC®; Diamond V) Saccharomyces cerevisiae feed additives on sow and litter performance. Sows were fed a common gestation diet (0.55% SID-Lysine) until d112 of pregnancy and then allotted to lactation treatments: 1) Control diet (CON; 1.00% SID-Lysine), 2) CON +15 mL of LIQP from d112 to weaning (LIQ), 3) CON +0.20% of XPC from d112 to weaning (DRY), and 4) DRY +15 mL of LIQP from d112 to d7 post-farrowing (D+L). The LIQP was given once daily using an oral dose gun and XPC was included in the feed. Immunoglobulin concentrations were estimated on colostrum samples using Brix refractometer and piglet d 1 serum immunocrit ratio and plasma IgA and IgG. Daily sow water intake and daily feed intake (DFI) from d112 of gestation to d7 post-farrowing and weekly feed intake (ADFI) were recorded. There were no treatment effects on sow BW, backfat, or loin depth (P >0.05) although sows from LIQ group had numerically smaller BW reductions compared to CON sows (4.9% vs 7.2%, P=0.19). LIQ sows had greater DFI and CON lower DFI during week 1 of lactation (P=0.04) as well as ADFI for weeks 2, 3, and overall lactation period (P< 0.01) with DRY and D+L sows being intermediate. Water intake, immunoglobulins, and litter performance did not differ among treatments (P >0.05) although pigs from LIQ sows, compared to CON, had numerically increased weaning (6.14 vs 5.82kg, P >0.05) and litter weights (63.2 vs 60.1kg, P >0.05). LIQ sows had 0.7 d reduced wean-to-estrus interval (P< 0.001) and tended to have greater conception rates (P=0.07). In conclusion, LIQ supplementation of lactating sows improves feed intake, allowing sows to keep body reserves, and have better subsequent rebreeding performance. [ABSTRACT FROM AUTHOR]

A developmental Bacillus based direct-fed microbial (DFM) was added to nursery pig diets to evaluate the effect on growth and health in two 35-d randomized complete block design experiments blocked on initial BW and sex. Experiment 1 used 315 weaned pigs (20.1 d of age; 6.11 kg initial BW) allotted to one of three diets: 1) Negative Control (NC; no antibiotics but with pharmacological Zn or Cu), 2) NC+DFM 0.55x109CFU, 3) NC+DFM 1.1x109CFU. Experiment 2 used 376 weaned pigs (17.8 d of age; 5.99 kg initial BW) allotted to one of four diets, the same 3 diets from Experiment 1 plus a lower inclusion rate: 4) NC+DFM 0.275x109CFU. Both studies had 15 replicates/treatment, 6-7 pigs/pen. Pigs were budget fed phase 1-3 diets (1.13 kg/pig; 2.72 kg/pig; and 6.35 kg/pig, respectively) and ad libitum fed Phase 4 diet to d35. For Experiment 1, during week 1 pigs fed the DFM tended to linearly decrease ADFI (P = 0.086) and linearly increase G:F (P = 0.085). During day 21-35 of Experiment 1 pigs fed DFM linearly increased ADG (P = 0.035) and quadratically increased ADFI (P = 0.027). Overall for experiment 1, ADG (P = 0.114) and ADFI (P = 0.104) tended to quadratically increase and G:F linearly increased (P = 0.012) with increasing concentrations of DFM. Experiment 2; during week 1 and 3 ADFI (P = 0.084, P = 0.050, respectively) quadratically increased and G:F (P = 0.081; P = 0.022, respectively) quadratically decreased as DFM increased in the diet. During d21-35 of experiment 2, ADG (P = 0.064) quadratically increased and G:F (P = 0.012) quadratically decreased as DFM increased. Overall for Experiment 2 ADFI numerically increased (4.3%) with no increase in ADG, resulting in a quadratic decrease in G:F (P = 0.010) as the DFM increased in the diet. Summarizing these two studies, the DFM product had its greatest effect increasing ADFI while inconsistently impacting gain and efficiency. [ABSTRACT FROM AUTHOR]

Progeny from sows fed diets containing a Bacillus licheniformis direct-fed microbial (DFM), an organic acid blend of medium and short chain fatty acids (OA), DFM+OA, or a control (CON) diet from d80 of gestation until weaning were used to determine if feeding CON, DFM, OA, or DFM+OA to the dam and/or progeny post-weaning improved nursery growth performance. Weaned pigs from 47 dams (n = 384, Initial BW=6.15 kg) were blocked by initial BW and sex and allotted (6 pigs/pen, 8 pens/treatment) to one of 8 nursery treatments. Pigs from CON sows were fed a negative (NC; no antibiotics, pharmacological Zn or Cu) or positive [PC; Neo-Terramycin phases 1 and 2 (827 and 551 ppm) and Carbadox phase 3 (55 ppm)] control diet. Pigs from sows fed DFM, OA, or DFM+OA were fed the NC diet or a diet representative of their dam. Diets with DFM contained 1.6x109 CFU/kg DFM and diets with OA contained 0.5, 0.4, and 0.3% OA in phases 1-3, respectively. Weaning weight was used as a covariate for nursery performance. For all phases and overall, PC fed pigs had greater ADG, ADFI, and G:F (P < 0.05). Feeding DFM or OA in sow diets improved (interaction; P< 0.042) nursery pig G:F, but DFM+OA offspring had no improvement for d7-14, 0-14, and 0-21 G:F. Feeding DFM or OA to sows and their progeny decreased ADFI (interaction; P < 0.042) but improved G:F (interaction; P < 0.028) for d7-14 and 0-14 with DFM+OA having no improvement above CON. For d14-21 and 0-21, feeding DFM or OA to sows and their progeny decreased ADFI whereas DFM+OA increased ADFI above CON (interaction; P < 0.019). In conclusion, feeding DFM or OA to sows or their offspring may improve nursery feed efficiency and feeding DFM+OA diet to sows and their progeny may increase ADFI late in the nursery period. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the effects of electronically controlled cooling pads on measures of physiological responses in HS gilts. The study utilized 12 gilts randomly assigned into one of three treatment groups [Control(CN), flush 2.0 L cool water over 30 s every 4 min(F4), or flush 2.0 L over 30 s every 8 min(F8)] in a Latin Square design and replicated 12 times(2 repetitions/d over 6 d). Gilts were housed in farrowing crates and fed 1.2 kg at 0700 and 1300 h daily. On d 1 to 3(6 repetitions) the room was gradually heated from 18ºC to 32ºC, while on d 4 to 6 the room was gradually heated from 18ºC to 35ºC starting at 0730 or 1330 h. Once the temperature was achieved, cooling pads were turned on and the temperature was maintained for 2.5 h. Two baseline measurements were taken of respiration rates(RR), skin temperature through thermal imaging(IRTemp), and vaginal temperature(VTemp) before room heating began and then recorded every 20 minutes after pads were turned on. Measurements at the end of HS(PostH) and the change in values during the HS period(DIFF) were evaluated using PROC mixed of SAS. Gilts in F4 and F8 had lower RR than CN for PostH for both 32ºC and 35ºC (P< .05). DIFF in RR was less in F4 and F8 than in CN[(32ºC, P=.097) and (35ºC, P=.005)]. There was a tendency for DIFF in Vtemp at 32ºC between treatments (P=.064) but had no effect by treatment for PostH (P=.534). There was no effect in PostH and DIFF for IRTemp between treatments for 32ºC and 35ºC. PostH and DIFF for VTemp were significant at 35ºC (P=.009 and P=.001). PostH for RR was different at 35 ºC and 32 ºC (P=.0074; P=.0472) with F4 and F8 lesser and CN. In conclusion, cooling pads, regardless of flush rate, had positive impacts on physiological indicators of HS. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of a liquid prototype (LIQP) and dry (XPC®; Diamond V) Saccharomyces cerevisiae feed additives on blood and uterine cytokine profiles in sows (n = 40). On d 112 of pregnancy sows were allotted to dietary treatments: 1) Control diet (CON), 2) CON +15 mL of LIQP (LIQ), 3) CON +0.20% of XPC (DRY), and 4) DRY +15 mL of LIQP until d 7 post-farrowing (D+L). Interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were quantified from serum samples collected on d 112 of gestation, d 2 and 6 post-farrowing, and from uterine fluid collected on d 2, 4, and 6 post-farrowing. Serum C-Reactive protein (CRP) and haptoglobin concentrations were evaluated. No interactions between treatments and day of collection were observed (P > 0.13). LIQ and D+L sows had the greatest serum IL-10 concentration (P < 0.001) and sows fed CON tended to have lower concentration of IL-8 (P < 0.06) vs. other treatments. Serum CRP concentrations were greatest on d 2 (P < 0.001), serum IL-10 (P < 0.04) and IL-4 (P < 0.07) linearly decreased while serum haptoglobin (P < 0.02) and INF-γ (P < 0.001) linearly increased post-farrowing. In the uterine fluid, LIQ and D+L sows had greater INF-γ (P = 0.04) concentrations and CON tended to have the least concentration of TNF-α (P = 0.08). Uterine fluid IL-1 tended to linearly increase (P < 0.07) and IL-6 linearly decrease (P < 0.01) post-farrowing. No strong correlations were detected between cytokines in the serum and uterine fluid within day. LIQ sows had the greatest daily feed intake and CON the least during the first week of lactation (P = 0.04). Providing LIQP post-farrowing to sows modified immune response increasing both pro- and anti-inflammatory cytokines in serum and uterine fluid in an independent manner, allowing animals a quicker recovery and increased feed intake. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the effects of electronically-controlled floor cooling pads on thermoregulatory and reproductive parameters in boars during heat stress (HS). Boars (n = 24) were randomly assigned to crates with non-functional pads (CON) or pads that were flushed in either 8-min intervals or when the pad reached 28.5°C (FLUSH). For 3 d, boars were subjected to cyclical HS (28 to 35°C; >65% relative humidity). Boars were fed 2.4 kg/d and daily feed intake was recorded. Respiration rate (RR), rectal temperature (Rtemp) and skin temperature were recorded every 2 h during HS (via IR camera), testicular temperature was recorded twice daily. Semen was collected d7 and d14 before HS, the day following HS and weekly for 6 weeks and evaluated for volume, sperm concentration, motility, progressive motility, morphological abnormalities, and viability. After 2 h of HS, FLUSH boars had reduced RR (P < 0.001) and RTemp (P < 0.001) when compared to control boars, and this difference was maintained throughout HS. Skin and testicular temperature were reduced in FLUSH vs. CON boars after 6 h of HS (P < 0.05). Semen volume was greater in FLUSH vs CON boars (P = 0.01) resulting in a tendency for an increase in total sperm per ejaculate (P = 0.075). From weeks 2 to 5 post-HS, FLUSH boars had increased motility (P = 0.006) and progressive motility (P = 0.001), with corresponding increases in sperm kinematic motion parameters when compared to CON boars. The number of morphologically normal sperm cells were increased (P = 0.006) in FLUSH vs CON boars due to reduced distal droplets (P = 0.033) and proximal droplets (P < 0.001). Abnormal acrosomes were reduced (P < 0.001) in FLUSH vs CON boars at week 3 post-HS. In summary, electronically controlled cooling pads effectively reduced negative thermoregulatory indicators of HS and minimized or removed the negative impacts of HS on semen quality in boars. [ABSTRACT FROM AUTHOR]

Genetically selecting for improved animal resilience has become of great interest in modern livestock breeding. In this context, piglets experience a transitory allergic response to soybean proteins that has a negative impact on their growth and welfare. The main objective of this study was to determine whether soybean allergy response is a heritable trait, using divergently selected pig lines. The base generation pigs were generated from nine sire lines (primarily Yorkshire and Landrace) and two dam sources (Yorkshire × Chester White F1 and Landrace × Yorkshire F1). Soybean allergic response was measured, following a skin test protocol, on pigs that received a diet containing 28% soybean meal for 21 consecutive days post-weaning. The skin test was performed with an intradermal injection of soybean protein. Wheel and flare scores (ranging from 0 to 3) were assigned approximately 60 minutes postinjection. Based on the skin test total scores (i.e., the sum of the wheal and flair scores, ranging from 0 to 6), animals were selected to create two (a high and a low) soybean protein reacting lines, and bred within lines for nine generations. Phenotypes used in this study were measured on a total of 5,505 animals born from generations one to nine, in both high and low reacting lines. Significant systematic effects (P < 0.05) included in the statistical model were birth year, birth season, sex, and weaning weight (as a covariate). Genetic parameters for the skin test were estimated using a pedigree-based relationship matrix containing 9,201 animals, and a threshold animal mixed model. The genetic variance estimated for soybean allergy was 0.091, indicating that there is genetic variability in this trait. The heritability estimated for soybean allergy response was 0.139, which indicates that food allergy response is a heritable trait and can be improved through selective breeding. [ABSTRACT FROM AUTHOR]

The study objective was to evaluate the impact of electronically controlled cooling pads on physiological measurements of heat stress during early lactation. Twelve sows (d 3 to 11 of lactation) were provided with a specially designed cooling pad. Sows randomly received no cooling (CONTROL, n=6) or pads set to flush 2L cool water every 30s when aluminum plate reached 29.5°C (TREAT, n=6). Respiration rates (RR), rectal temperatures (RT) and skin temperatures (ST, 15 cm posterior to the ear) were recorded daily (0700 and 1500 h) for seven days of early lactation. Feed intake (DFI) was measured daily at 0700 h. RR, RT, and ST were fitted to a model that included the effects of day, time, parity, cooling pad treatment, and interactions. DFI was fitted to the same model, excluding time of day. For RR: treatment, day, time, treatment by day, treatment by time, and day by time interactions were significant (P< 0.0004, CONTROL=49, TREAT= 30). Pad treatment had greater impact on RR during the first two days of the trial when the temperature was greater (32°C maximum CONTROL mean=66 vs. TREAT mean=30) than the following five days: 42, and 30 respectively). There was greater treatment impact on RR at 1500 versus 0700 h (0700 h: CONTROL= 35, TREAT= 25; 1500 h: CONTROL= 61, TREAT= 36). For RT: treatment, day, time, parity and interaction of day by time were significant (P< 0.01, CONTROL= 37, treat= 35.). For ST: treatment, day, time, parity and the interactions of time by parity, treatment by time, and day by time were significant (P< 0.0006, mean CONTROL=36.5, TREAT= 35.1). For DFI: day and the interaction of day by treatment were significant. The difference in feed intake between treatments increased as day increased. The use of electronically controlled cooling pads reduced measures of heat stress in early lactating sows. [ABSTRACT FROM AUTHOR]

Pork processors use marketing grids in which carcasses heavier or lighter than specified carcass weights (CW) are discounted in value. In North America most processors discount pigs further from the ideal CW at an increasing rate. To reduce sort loss, most commercial producers visually evaluate the body weight (BW) of each pig and try to identify the heaviest pigs in each pen for marketing on two-to four-day marketing windows. Carcass premiums/discounts are based on a predicted "percent lean" estimated using measurements of backfat depth and loin muscle depth. Usually, the premium for leanness has a nonlinear relationship with predicted percent lean. Optimal marketing maximizes daily return above variable costs including daily feed cost. Implementation requires that producers know: feed efficiency of their pigs relative to BW, variation in growth rates and BW amongst pigs within the herd, and the relationship between carcass leanness and CW. Sorting accuracy for marketing impacts the distribution of CWs, the sort loss, and depending on CW discounts, the optimal market BW's. Thus, sorting decisions are interrelated with marketing decisions. In three large barns, percentages of pigs sold correctly for the first two marketing cuts were 56, 48, and 52%, and differences in sort loss increased to $5.74/pig as mean CW increased. Methods have been developed to evaluate sorting accuracy. Pork processors have an optimal distribution of cut weights and sizes to maximize their daily returns above costs. Current marketing systems provide little incentive for commercial producers to reduce the variation in CW and subsequent cut weights and do not optimize the distribution of CWs. Next steps are to implement the state-of-the-art decision making on test farms, evaluate performance, refine and replicate a successful platform. To satisfy heterogeneous consumer demand at minimum cost joint optimization of farm production with wholesale marketing will be required. [ABSTRACT FROM AUTHOR]

An electronically controlled cooling pad has been developed to remove excess heat from sows using water cooled by flowing through underground pipes. This study was designed to evaluate different water flush rates on physiological measures of heat stress on day 16 to 21 of lactation. Twelve sows were randomly assigned to 3 treatments (control (CN), flush 2.0 L over 30 sec every 2.5 minutes (F2.5), or flush every 5 minutes (F5)) in a Latin square design. Feed intake (FI) was recorded daily at 0700 h. Temperatures were gradually increased from 22°C at 0800 h to 32°C by 0930 h. Then 32°C was maintained until 1500 h, when cooling of the room began. After 1800 h, the cooling pads were flushed every 9 minutes. Rectal temperature (RTemp), skin temperature (STemp), and respiration rates (RR) were measured at 0700, 0730, 0900, 1200, 1500, and 1800 h daily, with thermal imaging (IR) being taken at 1200 and 1500 h. The effects of flush rate (amount of water flushed) on STemp were linear (P=0.023), with means of 35.9, 35.0, and 35.9°C for the CN, F2.5, and F5.0 treatments. Pad flush rate effects of RTemp were linear (P< 0.001) and were greater in CN sows compared to F2.5 and F5 (39.3°, 38.8°, and 38.9°C), P< 0.0001). RR was affected by treatment (60 vs 42 and 50 breaths/min, P< 0.005 for CN, F2.5, and F5.0 treatments). Treatment by time interactions were significant for RR (P=0.0003) and RTemp (P=< 0.0001), with the greatest differences at 1200 and 1500 times (RR = 89, 48, & 65; and RTemp 39.9, 39.0, & 39.2°C for CN, F2.5, and F5.0 treatments). Skin temps measured by thermal imaging were not different among treatments (P=0.38) nor DFI (P=0.41). Cooling pad use with a flush rate of 2.0 L/2.5 min reduced body temperature to euthermia without increasing RR most effectively. This has implications toward reducing energy expenditure for thermoregulatory processes, which can increase nutrient availability for lactation during HS. [ABSTRACT FROM AUTHOR]

Induction can be a useful herd management tool. However, inducing too early can negatively impact critical biological processes for the sow and her piglets. Although inducing at 115 d of gestation is widely accepted for commercial sows, the natural gestation length of purebred lines can exceed 115 days. Therefore, the objective of this study was to estimate the effect of induction at 115 vs. 117 d of gestation on the performance of purebred sows and their piglets. Purebred Landrace females from a commercial multiplier were used for this study. Sows were mated to one of the following genetic lines: A, B, or C. Of the 601 sows placed on test, 264 and 135 sows farrowed as a result of induction at 115 or 117 days of gestation, respectively. From these 399 sows, piglets sired by line C (n=1,715) were used for subsequent analyses. Traits of the sow analyzed included: percent stillborn, sow mortality (from 0 to 24 days post-farrowing), and removal rate (between farrowing and weaning). Traits of the piglet analyzed included: weaning weight, lactation ADG, and pre-weaning mortality. All traits were analyzed using a generalized linear model, except for mortality and removal rate, which were analyzed using a LOGIT model. Piglets from the 117 group had significantly greater weaning weight (P=0.02), significantly greater ADG (P=0.0009), and numerically lower pre-weaning mortality (P=0.16) than piglets from the 115 group. Sows induced at 117 days of gestation had numerically lower percent stillborn, lower mortality, and lower removal rate than sows induced at 115 days of gestation, although not significant (P=0.13, P=0.48, and P=0.50, respectively). In conclusion, there was a numerically or significantly favorable effect of inducing sows at 117 vs. 115 d of gestation on both sow performance and earlylife piglet performance. [ABSTRACT FROM AUTHOR]

A total of 606 sows (PIC 1050) and their progeny (PIC 1050×280) were used to determine if feeding gestating and lactating sows a proprietary strain of Pichia guilliermondi as a whole-cell inactivated yeast product (WCY; CitriStim, ADM Animal Nutrition, Quincy, IL) improves sow and litter performance in a commercial production system. Once confirmed pregnant at d 35 post-breeding pregnancy check, sows were fed either a basal gestation control (CON) diet (0.55% SID Lysine) or the control diet fortified with 0.15% (1.36 kg/ton) of the WCY replacing corn in the CON diet. Dietary treatments were also fed in lactation (1.05% SID Lysine) once sows were moved into farrowing crates on approximately d 112 of gestation until weaning. Sows supplemented with WCY in gestation and lactation had a greater number of total born piglets by 0.45 pigs (P=0.040), born alive (P< 0.04), heavier born alive litter weight (P< 0.001), and greater post cross-foster litter size (P< 0.001) compared to CON fed sows. Litter size at weaning was increased by 0.54 pigs when sows were fed WCY compared to CON (P< 0.001). However, the average piglet weaning weights from CON fed sows were heavier by 0.35 kg compared to WCY (P< 0.001). This increase in body weight of piglets from CON fed sows is partially explained by their 0.93 days longer lactation (P< 0.001), and may also be due to the smaller litter size nursed throughout lactation. The percent of litters treated for scours decreased from 38.3% to 14.2% when sows were fed WCY (P< 0.001). The distribution of birth weights by body weight range was not different (P=0.2461) between treatments. In conclusion, feeding gestating and lactating sows a proprietary strain of Pichia guilliermondi as a whole-cell inactivated yeast product increased the number of piglets born and number weaned as well as decreased the prevalence of scours during lactation. [ABSTRACT FROM AUTHOR]

Inflammatory mediators, such as cytokines, can reduce feed intake and drastically modify the partitioning of nutrients. Thus, it may increase the animal's maintenance requirements, reduce milk production and piglet growth, impact reproductive performance, and reduce sow lifetime productivity. The objective of this experiment was to evaluate a non-invasive method, not tested before in swine, to assess cytokine profiles from post-partum uterine lavage. The uteri of second and third parity sows (n=14) were flushed with sterile saline solution (0.9%) on days 2, 4, and 14 postparturition. An artificial insemination (AI) catheter, in its plastic covering, to avoid vaginal contents, was inserted through the vagina into the cervix. A flexible inner catheter was passed through the outer AI catheter and into the uterine horn. Sterile saline (30-40 mL) was flushed through the inner catheter into one uterine horn. After inner catheter removal, a tube was attached to the end of the outer AI catheter to allow collection of the natural back-flow of uterine lavage fluid (avg 24.7% recovery). Uterine fluid collected was immediately centrifuged and the supernatant stored at -20°C. Samples were freeze-dried, re-suspended in sterile saline (2 mL), and stored at -80°C. Cytokine profiles of the uterine fluid were evaluated using a multiplex ELISA panel including interleukin (IL)-1β, IL-6, IL-8, IL-4, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Cytokine concentrations were calculated relative to protein content (pg/mg of protein). IFN-γ and TNF-α were lower than the limit of detection in most samples (5/38 and 1/38, respectively). IL-4 and IL-10 concentrations did not differ among days of collection (P >0.14). IL-8 was greater on day 4 than on days 2 or 14 (P< 0.05). IL-1β and IL-6 were greater on days 2 and 4 than on day 14 (P< 0.05). Uterine flushing is a novel non-invasive method to access uterine inflammatory cytokines in sows. [ABSTRACT FROM AUTHOR]

Pregnant sows, especially during late-gestation, may be susceptible to heat stress due to increased metabolic heat production and body mass. Therefore, the study objective was to determine the thermoregulatory and physiological responses of sows exposed to increasing ambient temperature (TA) at 3 reproductive stages. In 3 repetitions, 27 multiparous sows (parity 3.22±0.89) were individually housed and had jugular catheters placed 5.0±1.0 d prior to the experiment. To differentiate between reproductive stages, sows were categorized as open (not pregnant, n=9), mid-gestation (59.7±9.6 days pregnant, n=9), or late-gestation (99.0±4.8 days pregnant, n=9). During the experiment, sows were exposed to 6 consecutive 1 h periods of increasing TA (period 1, 14.39±2.14°C; period 2, 16.20±1.39°C; period 3, 22.09±1.87°C; period 4, 26.34±1.39°C; period 5, 30.56±0.81°C; period 6, 35.07±0.96°C), with 1 h transition phases in between each period. Respiration rate (RR), heart rate (HR), skin temperature, and vaginal temperature (TV) were measured every 20 min and the mean was calculated for each period. At the end of each period, blood gases, leukocytes, and red blood cell counts were measured. Overall, RR and HR were greater (P=0.04; 45.6% and 12.9%, respectively) in late-gestation versus mid-gestation sows. Compared to mid-gestation and open sows, TV tended to be greater (P=0.06) during period 4 (0.18°C and 0.29°C, respectively) and period 5 (0.14°C and 0.18°C, respectively) in late-gestation sows. Blood O2 increased (P< 0.01; 18.1%) for all sows with advancing period, regardless of reproductive stage. Late-gestation sows had reduced (P=0.02; 16.1%) blood CO2 compared to mid-gestation sows, regardless of period. In summary, late-gestation sows appear to be more sensitive to increasing TA as indicated by increased RR, HR, TV, and blood O2, and reduced blood CO2 when compared to mid-gestation or open sows. This change in O2 and CO2, due to increasing RR and heat stress sensitivity of late-gestation sows, may suggest an alteration to the acid-base balance, leading to respiratory alkalosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Aggression after mixing has negative effects on growth performance and animal welfare in pigs. To analyze the temporal dynamics of social hierarchy formation and maintenance, a total of 102 weaned pigs (47 females and 55 barrows) were selected and blocked by sex and body weight. The pigs were mixed into 10 single-sex pens (10 to 11 pigs/pen) avoiding original littermates. Their behavior was recorded and observed for 72 h after mixing for the analysis of dominance hierarchy indices in each pen. The three hierarchical indices: I&SI, Elo rating, and Glicko rating, were associated with each other (|r| = 0.681~0.942, p < 0.001). I&SI was associated with the logarithms of frequency of active attack (|r| = 0.65, p < 0.05) and tended to be associated to logarithms of frequency of standoff (|r| = 0.48, p < 0.1). Elo rating, and Glicko rating were associated with logarithms of duration of being bullied (|r| = 0.393~0.401, p < 0.05). In addition, Glicko rating tended to be associated with the logarithms of duration of active attack and frequency of active attack (|r| = 0.416~0.439, p < 0.1). Multiple linear regression analyses of logarithms of dyadic behavior indicators for hierarchical indices indicated the same effects. The rank of pigs became stable earlier (p < 0.001) in females (23.06 ± 4.15 h post mixing) than in barrows (40.55 ± 4.71 h post mixing). The first ranked pig quickly appeared within a few hours after mixing and remained stable. Our study provided new insights into the re-establishment of social hierarchies in weaned pigs after mixing. Pigs are animals that live in groups and have social hierarchies within the group. After mixing, they can re-establish social hierarchies within several days through fighting. Dominance hierarchical indices, such as I&SI, Elo rating, and Glicko rating, have been used to analyze social hierarchies of some social animals but not pigs. I&SI index involves iterative calculations that first minimize the number of inconsistencies (I) in a dominance matrix, and then minimize the strength of those inconsistencies (SI). Elo rating and Glicko rating indices are based on the sequence in which interactions occur, and continuously update ratings by looking at interactions sequentially. To study the temporal dynamics of social hierarchy formation and maintenance in weaned pigs after mixing, a total of 102 pigs (47 females and 55 barrows) were selected by similar body weight and mixed in 10 pens (10 or 11 females or barrows per pen). Their behavior was recorded and observed for 72 h after mixing. Results showed that hierarchical indices I&SI, Elo rating, and Glicko rating were associated with each other (|r| = 0.681 ~ 0.942, p < 0.001). I&SI was associated with logarithms of frequency of active attack (|r| = 0.65, p < 0.05) and tended to associated with logarithms of frequency of standoff (|r| = 0.48, p < 0.1). Elo rating, and Glicko rating were associated with the logarithms of duration of being bullied (|r| = 0.393~0.401, p < 0.05). In addition, Glicko rating tended to be associated with the logarithms of duration of active attack and frequency of active attack (|r| = 0.416~0.439, p < 0.1). Multiple linear regression analyses of logarithms of dyadic behavior indicators for three hierarchical indices indicated the same effects. The time (hours) to achieve social stability of pigs after mixing was lower for females than barrows (23.06 ± 4.15 vs. 40.55 ± 4.71 h; p < 0.001). The most dominant pig (the first ranked) in each pen quickly appeared within a few hours after mixing and remained stable. Overall, our study demonstrated that the ranks calculated by the three dominance hierarchical indices: I&SI, Elo rating, and Glicko rating, were consistent and partially associated with part of the dyadic behavioral indicators in weaned pigs after mixing. [ABSTRACT FROM AUTHOR]

In pig production, pigs often show more aggressive behavior after mixing, which adversely affects animal welfare and growth performance. The Jumonji and structural domain-rich AT interaction domain 2 (JARID2) gene plays an important role in neurodevelopment in mice and various psychiatric disorders in humans. The JARID2 gene may impact the aggressive behavior of pigs. By observing the behavior of 500 weaned pigs during the first 72 h after mixing, the ear tissue samples of the 12 most aggressive and 12 least aggressive pigs were selected for DNA resequencing based on the intensity of their aggressive behavior. Large group correlation analysis indicated that the rs3262221458 site located in the 3′-UTR region of the porcine JARID2 gene has a strong relationship with the aggressive behavior of weaned pigs. Pigs with the mutant TT genotype of rs3262221458 have more aggressive behavior than those pigs with the GG and GT genotypes. The dual luciferase assay indicated that the luciferase activity of the plasmids containing the G allele of rs326221458 was significantly less than that of plasmids containing the T allele of rs326221458 and control groups. The binding ability of miR-9828-3p to sequences containing the T allele was less than that of sequences containing the G allele. The overexpression of miR-9828-3p in porcine neuroglial cells (PNGCs) and PK15 cells significantly decreased the mRNA and protein levels of the JARID2 gene. In addition, miR-9828-3p inhibited the proliferation of PNGCs. After inhibiting miR-9828-3p, the mRNA and protein expression levels of JARID2 increased, and the proliferation of PNGCs showed an opposite trend to the cells that forced the expression of miR-9828-3p. In addition, interference with the JARID2 gene by siRNA can effectively inhibit the proliferation of PNGCs. In summary, we found that the rs326221458 locus regulates the expression of the JARID2 gene by affecting the binding of miR-9828-3p and the JARID2 gene, thereby affecting the aggressive behavior of weaned pigs after mixing. [ABSTRACT FROM AUTHOR]

Lactating sows and their litters are particularly vulnerable to heat stress (HS). HS decreases fertility, feed intake, milk production, and litter growth of sows. Approaches are needed to mitigate the negative effects of HS on animal welfare and oxidative damage to tissues. The objective of this study was to measure the efficacy of conductive heat removal using electronic cooling pads (ECP) and feeding Moringa oleifera (4% of the diet, M), a feedstuff high in antioxidants, to sows from late gestation to weaning on their welfare and production performance. A study was conducted using a 2 × 2 factorial design of treatments, with mixed parity Yorkshire × Landrace sows (n  = 48). The sows were exposed to moderate HS conditions from gestation day 110 to day 21 of lactation. To achieve moderate HS, the farrowing room temperature was increased incrementally daily from 25 °C to 32 °C between 0800 and 1100 hours and decreased from 32 °C to 26 °C between 1700 and 2000 hours. Sows were limit fed during gestation (1.36 kg 2X/d) and fed ad libitum post farrowing. Treatments included HS + control corn–soybean meal (CS)-based diet (HS + CS), HS + M, ECP + CS, ECP + M (n  = 12/treatment). Sow respiration rate (RR) and rectal temperature (RT) were measured four times daily (0600, 1300, 1600, and 1900 hours). The use of ECP decreased lactating sow RR (HS = 66.6 bpm, ECP = 28.3 bpm, P <  0.0001), RT (HS = 39.2 °C, ECP = 38.8 °C, P =  0.003), and lactation body weight (BW) loss (HS = −21.67 kg, ECP = −5.1 kg P =  0.002). ECP by time-of-day interactions (P <  0.01) existed for RR and RT, with ECP having a greater impact from 1300 to 1900 hours, than at 0600 hours. ECP increased the intake of lactation feed (P =  0.02). An ECP by diet interaction (P =  0.0004) indicated that ECP increased the intake of lactation feed for the sows fed the CS diet (6.48 vs. 4.42 kg/d, P =  0.0004), but did not affect the feed intake of sows fed the M diet. The treatment did not affect litter weaning weight (P =  0.14). Moringa increased percent fat in milk (M = 12.28%, CS = 11.06%, P =  0.05). The reduction in sow RR and RT, and increase in feed intake with lower loss of BW indicate that ECP improved sow well-being in the HS environment. Neither ECP nor M affected litter growth, despite M increasing fat content of milk and ECP–CS increasing feed intake. [ABSTRACT FROM AUTHOR]

Overnutrition or undernutrition during all or part of the reproductive cycle predisposes sows to metabolic consequences and poor reproductive health which contributes to a decrease in sow longevity and an increase in perinatal mortality. This represents not only an economic problem for the pig industry but also results in poor animal welfare. To maximise profitability and increase sustainability in pig production, it is pivotal to provide researchers and practitioners with synthesised information about the repercussions of maternal obesity or malnutrition on reproductive health and perinatal outcomes, and to pinpoint currently available nutritional managements to keep sows' body condition in an optimal range. Thus, the present review summarises recent work on the consequences of maternal malnutrition and highlights new findings. [ABSTRACT FROM AUTHOR]

Simple Summary: Fresh pork quality is an important discriminator for consumers making purchasing decisions. As such, this issue deserves significant attention from all sectors of the swine industry. Development of pork quality is a complex process predicated largely on the metabolism that occurs in the muscle after death. Mechanisms driving this biochemistry are not well established but are sensitive to pig genetic line and postmortem handling procedures. We attempted to unravel some of these processes by subjecting three different breeds of pigs to electrical stimulation postmortem in an effort to simulate adverse handling events after stunning. We then described the muscle characteristics of these lines and monitored metabolite accumulation in the tissue over 24 h and related it to ultimate pork quality. Differences in myosin heavy chain (MyHC) and metabolism were detected across genetic lines, but pork quality was generally unaffected. These data show different genetic lines can impact postmortem metabolism but a greater understanding of mechanisms controlling the transformation of muscle to meat is necessary before we can select for tissue parameters to improve fresh pork quality development and consistency. Variations in postmortem metabolism in muscle impact pork quality development. Curiously, some genetic lines are more refractile to adverse pork quality development than others and may regulate energy metabolism differently. The aim of this study was to challenge pork carcasses from different genetic populations with electrical stimulation (ES) to determine how postmortem metabolism varies with genetic line and explore control points that reside in glycolysis in dying muscle. Three genetic populations (GP) were subjected to ES (100 V or 200 V, 13 pulses, 2 s on/2 s off) at 15- or 25-min post-exsanguination, or no stimulation (NS). Genetic population affected relative muscle relative abundance of different myosin heavy chains, glycogen, G6P, and lactate concentrations. Genetic lines responded similarly to ES, but a comparison of ES treatment groups revealed a trend for an interaction between voltage, time of ES, and time postmortem. Higher voltage accelerated pH decline at 20 min up to 60 min postmortem. Trends in color and firmness scores and L* values were consistent with pH and metabolite data. These data show that genetic populations respond differently to postmortem perturbation by altering glycolytic flux and suggest differences in postmortem glycolysis may be partially responsible for differences in meat quality between genetic populations, though not entirely. [ABSTRACT FROM AUTHOR]

Prediction equations for pork carcass lean percentage are widely used in Extension, teaching, and research. Prediction equations using carcass or live animal measurements are used in carcass contests, live animal evaluation, and marketing. Fat--free lean gain is used to estimate the daily lysine requirements for pigs in swine nutrition guides. The use of inaccurate equations has substantial economic impact. Extension specialists must make the effort to confirm the accuracy of the equations they recommend for use. Standards of prediction accuracy and biases must be developed to assure that accurate equations are developed and recommended for industry use. [ABSTRACT FROM AUTHOR]

An accurate understanding of heat stress (HS) temperatures and phenotypes that indicate HS tolerance is necessary to improve swine HS resilience. Therefore, the study objectives were 1) to identify phenotypes indicative of HS tolerance, and 2) to determine moderate and severe HS threshold temperatures in lactating sows. Multiparous (4.10 ± 1.48) lactating sows and their litters (11.10 ± 2.33 piglets/litter) were housed in naturally ventilated (n = 1,015) or mechanically ventilated (n = 630) barns at a commercial sow farm in Maple Hill, NC, USA between June 9 and July 24, 2021. In-barn dry bulb temperatures (TDB) and relative humidity were continuously recorded for naturally ventilated (26.38 ± 1.21 °C and 83.38 ± 5.40%, respectively) and mechanically ventilated (26.91 ± 1.80 °C and 77.13 ± 7.06%, respectively) barns using data recorders. Sows were phenotyped between lactation days 11.28 ± 3.08 and 14.25 ± 3.26. Thermoregulatory measures were obtained daily at 0800, 1200, 1600, and 2000 h and included respiration rate, and ear, shoulder, rump, and tail skin temperatures. Vaginal temperatures (TV) were recorded in 10 min intervals using data recorders. Anatomical characteristics were recorded, including ear area and length, visual and caliper-assessed body condition scores, and a visually assessed and subjective hair density score. Data were analyzed using PROC MIXED to evaluate the temporal pattern of thermoregulatory responses, phenotype correlations were based on mixed model analyses, and moderate and severe HS inflection points were established by fitting TV as the dependent variable in a cubic function against TDB. Statistical analyses were conducted separately for sows housed in mechanically or naturally ventilated barns because the sow groups were not housed in each facility type simultaneously. The temporal pattern of thermoregulatory responses was similar for naturally and mechanically ventilated barns and several thermoregulatory and anatomical measures were significantly correlated with one another (P < 0.05), including all anatomical measures as well as skin temperatures, respiration rates, and TV. For sows housed in naturally and mechanically ventilated facilities, moderate HS threshold TDB were 27.36 and 26.69 °C, respectively, and severe HS threshold TDB were 29.45 and 30.60 °C, respectively. In summary, this study provides new information on the variability of HS tolerance phenotypes and environmental conditions that constitute HS in commercially housed lactating sows. [ABSTRACT FROM AUTHOR]

Disruption of the estrous cycle affects fertility and reproductive health. Follicular dynamics are key to the regularity of the estrous cycle. We identified a novel lincRNA, HEOE, showing significant upregulation in the ovaries during the estrus phase across various pig breeds. Functional analysis revealed that HEOE is responsive to luteinizing hormone (LH) stimulation, modulating transcriptional suppression and alternative splicing in ovarian granulosa cells (GCs). This leads to increased GC apoptosis and inhibition of proliferation. Mechanistically, HEOE inhibits miR-16 maturation in the nucleus, and sequesters miR-16 in the cytoplasm, thereby collectively reducing miR-16's inhibition on ZMAT3, enhancing the expression of ZMAT3, a key factor in the p53 pathway and alternative splicing, thereby regulating follicular development. This effect was validated in both mice and pig follicles. Persistent overexpression or suppression of HEOE throughout the estrous cycle impairs cycle regularity and reduces litter size. These outcomes are associated with HEOE reduced follicular PGF2α levels and modulation of the cAMP signaling pathway. Our data, combined with public databases, indicate that the high expression of HEOE during the estrus phase is crucial for maintaining the estrous cycle. HEOE is a potential therapeutic target for regulating fertility and ensuring estrous cycle regularity in pigs. • HEOE regulates p53 and alternative splicing through miR-16-ZMAT3. • HEOE regulates granulosus cell proliferation and apoptosis. • HEOE reduces follicular PGF2α and affects the cAMP pathway. • HEOE, a novel lincRNA, crucially regulates fertility and estrous cycles in pigs. • High HEOE expression during estrus is essential for maintaining fertility. [ABSTRACT FROM AUTHOR]

Variation in genes of the serotonergic system influences aggressive behavior by affecting serotonin levels in the central and cortical nervous system. SLC6A4 (serotonin transporter) is a master regulator of 5-HT signaling and involved in the regulation of aggressive behavior in humans and rodents. To identify potential functional single nucleotide polymorphisms (SNPs) for the porcine SLC6A4 gene associated with aggressive behavior, a total of 500 pigs (268 barrows and 232 gilts) were selected and mixed in 51 pens. Their behavior was recorded and observed for 72 h after mixing. Based on a composite aggressive score (CAS), the most aggressive and the least aggressive pigs within each pen were selected separately (a total of 204 pigs). Ear tissue was sampled to extract genomic DNA. Eight SNPs in the 5ʹ-flanking region, coding region, and 3ʹ-untranslated region (3ʹ-UTR) of SLC6A4 were genotyped, of which 6 SNPs had significant differences (P  < 0.05) in allele frequency between the most aggressive and least aggressive pigs. Luciferase activity was greater in plasmids of genotype GG than plasmids of genotype CC of rs345058216 (P  < 0.01). Computational analysis nominated MAZ as putative transcription factor (TF) with higher probability to bind the SLC6A4 promoter at the SNP (rs345058216) site. Also, we demonstrated that MAZ overexpression modulates SLC6A4 promoter activity in allele-specific manner with an in vitro assay. In addition, we demonstrated that SLC6A4 was a direct target of miR-671-5p. The dual luciferase reporter gene assay and cell transfection were performed to examine the role of miR-671-5p in regulating SLC6A4 expression. The luciferase assays revealed that the SNP rs332335871 affects regulation of miR-671-5p in SLC6A4 expression. After overexpression of miR-671-5p in porcine primary neural cells, the SLC6A4 mRNA levels can be significantly reduced. In conclusion, we here found that miR-671-5p and MAZ mediated porcine SLC6A4 expression level, which provides the possible molecular mechanism of aggressive behavior. [ABSTRACT FROM AUTHOR]

Porcine 17-hydroxysteroid dehydrogenase type 14 (HSD17B14) and FSH reporter (FSHR) genes play important roles in the metabolism of steroid hormones and the apoptosis of ovarian granulosa cells (GCs). Our bioinformatics analyses and the dual luciferase reporter assays indicated that porcine miR-20b and miR-31 target the 3′-UTR region of HSD17B14 gene, and miR-31 also targets the 3′-UTR region of FSHR gene. Overexpression of porcine HSD17B14 gene promoted the conversion from estradiol (E2) to estrone (E1) and increased the apoptosis of porcine GCs. Overexpression of miR-20b down-regulated the mRNA and protein expression level of HSD17B14 gene, decreased the concentration of progesterone (P4) and E1, increased E2, as well as reduced apoptosis of GCs. Moreover, overexpression of miR-31 also down-regulated the protein expression level of HSD17B14 gene, decreased the concentration of P4 and E1, and increased E2. However, miR-31 promoted apoptosis of GCs by targeting to the 3′-UTR of porcine FSHR gene. Taken together, we found that both porcine miR-20b and miR-31 target HSD17B14 gene, but miR-31 also targets FSHR gene to regulate the metabolism of steroid hormones and the apoptosis of porcine ovarian GCs. These findings expand the epigenetic regulatory mechanism of porcine miR-31 and miR-20b in ovarian GCs. • Both HSD17B14 and FSHR are the target genes of miR-31 in porcine GCs. • HSD17B14 is a target gene of miR-20b in porcine GCs. • Both miR-31 and miR-20b affected steroid hormone metabolism. • miR-31 promoted GC apoptosis, while miR-20b decreased GC apoptosis. [ABSTRACT FROM AUTHOR]

Characterizing the sow physiological response to an increased heat load is essential for effective heat stress mitigation. The study objective was to characterize the effects of a 400-min heating episode on sow heart rate variability (HRV) at different reproductive stages. HRV is a commonly used noninvasive proxy measure of autonomic function. Twenty-seven sows were enrolled in the study according to their gestation stage at time of selection: 1) nonpregnant (NP; n = 7), 2) mid-gestation (MID; 57.3 ± 11.8 d gestation; n = 11), and 3) late-gestation (LATE; 98.8 ± 4.9 d gestation; n = 8). The HRV data utilized in the study were collected from each pig as the dry bulb temperature in the room increased incrementally from 19.84 ± 2.15 °C to 35.54 ± 0.43 °C (range: 17.1–37.5 °C) over a 400-min period. After data collection, one 5-min set of continuous heart rate data were identified per pig for each of nine temperature intervals (19–20.99, 21–22.99, 23–24.99, 25–26.99, 27–28.99, 29–30.99, 31–32.99, 33–34.99, and 35–36.99 °C). Mean inter-beat interval length (RR), standard deviation of r-r intervals (SDNN), root mean square of successive differences (RMSSD), high frequency spectral power (HF), sample entropy (SampEn), short-term detrended fluctuation analysis (DFAα1), and three measures (%REC, DET, LMEAN) derived from recurrence quantification analysis were calculated for each data set. All data were analyzed using the PROC GLIMMIX procedure in SAS 9.4. Overall, LATE sows exhibited lower RR than NP sows (P < 0.01). The standard deviation of r–r intervals and RMSSD differed between each group (P < 0.01), with LATE sows exhibiting the lowest SDNN and RMSSD and NP sows exhibiting the greatest SDNN and RMSSD. Late-gestation sows exhibited lower HF than both MID and NP sows (P < 0.0001), greater DFA values than NP sows (P = 0.05), and greater DET compared to MID sows (P = 0.001). Late-gestation also sows exhibited greater %REC and LMEAN compared to MID (P < 0.01) and NP sows (all P < 0.01). In conclusion, LATE sows exhibited indicators of greater autonomic stress throughout the heating period compared to MID and NP sows. However, temperature by treatment interactions were not detected as dry bulb increased. Future studies are needed to fully elucidate the effect of gestational stage and increasing dry bulb temperature on sow HRV. [ABSTRACT FROM AUTHOR]

The metabolic heat production of modern pigs has increased by an average of 16%, compared with sows of 30 years ago. Therefore, it is likely that temperature recommendations require updating to meet the needs of modern pigs. The objective of this study was to evaluate whether different reproductive stages of sows altered thermal preference and if current recommendations required updating. Twenty multiparous sows (3.4 ± 1.2 parity) in different reproductive stages (nonpregnant: n = 7; mid-gestation: 58.5 ± 5.68 d, n = 6; and late-gestation: 104.7 ± 2.8 d, n = 7) were tested. Thermal preference was individually tested, and sows could freely choose a temperature, using a thermal gradient between 10.4 and 30.5 °C. Sows were given 24 h to acclimate to the thermal apparatus. Before testing began, sows were given daily feed allotment and returned to the apparatus. Video from the 24-h test period was used to record sow behavior (time spent inactive), posture (upright and sternal and lateral lying), and location using instantaneous scan samples every 15 min. Data were analyzed using PROC MIXED procedure in SAS 9.4. A cubic regression model was used to calculate the sow’s most preferred temperature based on the location, or temperature, in which they spent the most time. The preference range was calculated using peak temperature preference ±SE for each sow. The reproductive stage altered where sows spent their time within the thermal gradient (P < 0.01). Late-gestation sows preferred cooler temperatures (14.0 °C) than mid-gestation (14.8 °C; P < 0.01) and nonpregnant sows (14.8 °C; P < 0.01). In summary, sow thermal preferences were within the lower half of the current recommended range (10 to 25 °C). This indicates that temperatures at the higher end of the recommended range could be uncomfortable to sows and that the thermal comfort zone of sows may be narrower than recommendations indicate. [ABSTRACT FROM AUTHOR]

• Thermocouples provide a fastest reacting, accurate sensor for cooling pad work. • The digital thermal probes have significant lag associated with their responses. • A thermal 'offset' may be calculated for differences between sensors or placement. • The horizontal probe orientation was the fastest responding within the cooling pad. Heat stress in domestic animal production consistently alters several physiological, growth, and reproductive metrics within the livestock industry. To increase commercial productivity and general animal husbandry, the agricultural research community has been investigating technologies to combat the effects of heat stress for several decades. A hog cooling pad has been developed at Purdue University through a departmental collaboration between Agricultural & Biological Engineering and Animal Sciences. One of the main points of interest in the hog cooling pad research investigation is the accurate expression of the heat transfer from the sow to the copper coil coolant system. It is vital to obtain accurate temperature data in real time to properly manage the coolant flow in the device. This research project investigated the effect of the temperature probe orientation. Several cooling pad temperature probe orientations were proposed, while trying to keep every other operational aspect of the hog cooling pad the same. Temperature data from two separate collection systems were assessed using analyses that document differences in the selected probe's responsiveness and accuracy. Three placement areas were examined: the blade, center, and ham locations. This research demonstrated conclusively that the type K thermocouple collection system maintained an accurate, rapid, and consistent performance as the calibrated system, and the Hilitchi® digital probes varied substantially in accuracy and responsiveness. Calibration offset values for digital probes were documented in the 4–5 °C range. This was completely unacceptable for the small ranges of interest in the hog cooling pad work. Horizontal orientations were shown to be the most responsive against 45° orientations with: (t H (37.8) = −14.09, p < 0.01), (t C (41.8) = −9.57, p < 0.01), and (t B (44.5) = −15.08, p < 0.01); and against 90° orientations with: (t H (56.0) = −28.46, p < 0.01), (t C (36.9) = −10.14, p < 0.01), and (t B (53.8) = −13.48, p < 0.01). However, none of the test results indicated that the Hilitchi® digital probes performed acceptably enough to be included in any commercial build of the hog cooling units. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of the complex regulatory mechanisms governing estrus and ovulation across multiple tissues in mammals is imperative to improve the reproductive performance of livestock and mitigate ovulation-related disorders in humans. To comprehensively elucidate the regulatory landscape, we analyzed the transcriptome of protein-coding genes and long intergenic non-coding RNAs (lincRNAs) in 58 samples (including the hypothalamus, pituitary, ovary, vagina, and vulva) derived from European Large White gilts and Chinese Mi gilts during estrus and diestrus. We constructed an intricate regulatory network encompassing 358 hub genes across the five examined tissues. Furthermore, our investigation identified 85 differentially expressed lincRNAs that are predicted to target 230 genes associated with critical functions including behavior, receptors, and apoptosis. Importantly, we found that vital components of estrus and ovulation events involve "Apoptosis" pathway in the hypothalamus, "Autophagy" in the ovary, as well as "Hypoxia" and "Angiogenesis" in the vagina and vulva. We have identified several differentially expressed transcription factors (TFs), such as SPI1 and HES2 , which regulate these pathways. SPI1 may suppress transcription in the autophagy pathway, promoting apoptosis and inhibiting the proliferation of ovarian granulosa cells. Our study provides the most comprehensive transcriptional profiling information related to estrus and ovulation events. • A multi-tissue regulatory network for estrus and ovulation was constructed. • Three lincRNAs and two transcription factors related to estrus were identified. • Apoptosis, autophagy, and hypoxia pathways play key roles in ovulation events. • SPI1 promotes apoptosis and inhibits proliferation of ovarian granulosa cells. [ABSTRACT FROM AUTHOR]

In recent years, the concept of animal welfare began to be accepted by the Chinese people. On some intensive pig farms, the stocking density for growing pigs is too great, leading to decreased animal welfare. In order to study the relationships between stocking density and welfare indicators and determine the optimal stocking density for growing pigs, a total of 243 Landrace × Large White cross barrows were randomly regrouped at 1.6 m2, 1.2 m2 or 0.8 m2 per pig at 135 days of age. Behavior percentages, lesions on the body and tail, body surface temperature (BST), manure on the body and concentrations of salivary cortisol were measured during the first 15 days after regrouping. Pigs housed at 0.8 m2 per animal spent more time drinking (1.89 vs. 1.01%, P = 0.0048) and participating in negative social behavior (0.76 vs. 0.26%, P = 0.0063) than those housed at 1.6 m2 per pig. Pigs housed at 1.2 m2 per animal showed more positive social behaviors (1.28 vs. 0.14%, P = 0.04) than those housed at 1.6 m2. Pigs housed at 0.8 m2 per animal had more lesions on the ears (P < 0.01), front (P < 0.01), middle (P < 0.01) and hind-quarters (P < 0.01) regions than those housed at 1.6 and 1.2 m2. Total scores of lesions on the body were gradually increased (P < 0.01) with the increasing stocking density. Pigs housed at 0.8 m2 per animal had more manure on their bodies than pigs at 1.6 and 1.2 m2 at the 7th, 11th, 13th and 15th day after regrouping. Pigs housed at 0.8 m2 per animal had a greater proportion of pigs with an abnormally high BST than those at 1.6 (10 vs. 1.9%, P = 0.009) and 1.2 (10 vs. 4%, P = 0.037) m2 per pig. Altogether, at the first 15 days after regrouping, pigs housed at 1.2 m2 per animal had decreased housing costs compared to those housed at 1.6 m2 and improved indicators of animal welfare compared to those housed at 0.8 m2. [ABSTRACT FROM AUTHOR]