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Serum creatinine (SCr) in humans has proven to be a reliable biomarker of body protein breakdown and/or muscle mass change. This study set out to investigate the potential of SCr to indicate a loss in sow muscle mass over lactation, validated against 3 methyl histidine (3MH) and blood urea nitrogen (BUN), markers of dietary and/or body protein breakdown. A total of 40 sows were allocated to four treatment groups aimed to induce body weight changes by restrictively feeding sows using a stepwise percentage reduction model. Data were pooled and reallocated into three groups representing the 25th , 50th and 75th percentiles based on body weight change over lactation in the range -22.3 to -4.1% (treatment 25), -4.0 to 6.2% (Treatment 50), and 6.3-15.2% (Treatment 75). Indirect measures for the prediction of protein (3MH, BUN) or fat change (caliper, P2) were taken on entry into the farrowing house, day 5 of lactation, and at weaning. Serum was collected on these days, and SCr, 3MH and BUN were analysed. Piglet weaning weight and average daily feed intake did not differ between treatments (p > .05). There were no changes (p > .05) in indirect measures of body composition (sow caliper score, P2) and analytes (SCr, 3MH, BUN) over lactation. By day 20, those sows in treatment 25 had higher (p .05) and did not correlate with SCr change (p > .05) but were highly correlated to BUN change (R2 = 0.691, p < .001). The data suggested that concentrations of SCr and BUN may have been the result of dietary and/or body protein breakdown and/or changes in muscle mass. In the current testing conditions, SCr was not a reliable marker of changes in muscle mass.

Sows undergo physiological stress during gestation and lactation, potentially leading to enteric dysbiosis and reduced reproductive potential. Phytogenic additives (PFs) may improve performance via their antioxidant, anti-inflammatory and antimicrobial properties. This study determined whether the provision of a gestation/lactation diet containing PAs would alter the gastrointestinal microbiota of sows and their piglets, and improve performance. Sows received a commercial diet throughout gestation and lactation (CTR; n = 64), a commercial diet throughout gestation and a diet containing PAs in lactation (CTR-PA; n = 63) or a commercial diet containing PAs in gestation and lactation (PA; n = 90). Sows were weighed and backfat recorded after mating and at entry and exit from the farrowing house and piglets were weighed on days 1 and 21 of life. Faecal samples collected from sows at farrowing house entry and piglets at 21 and 35 d were subjected to 16 S rRNA gene amplicon analysis. The addition of PAs to sow diets resulted in more piglets born (P = 0.03), however, it did not improve the number of liveborn piglets (P = 0.14). There were no differences in sow weight, P2 backfat depth or lactation feed intake observed. PAs had no effect on piglet weight or survival to weaning but did alter the faecal microbiota of sows, and this change was observed in piglets at 21 and 35 d. PA supplementation to sows has the potential to increase litter size, while also potentially influencing gastrointestinal tract health of the sow and piglets reared. Supplementary Information The online version contains supplementary material available at 10.1186/s13568-021-01268-8.

Feeding fibre and branched-chain amino acids (BCAA) to sows during late gestation and lactation, respectively, have been shown to improve litter weights at weaning. Therefore, supplementing primiparous sow diets with lucerne chaff, a feedstuff high in fibre, BCAA and tryptophan, may improve the performance of their progeny. Experiment 1 investigated the effects of feeding primiparous sows (n = 118) either (i) a control diet (CON), (ii) CON with 1 kg of lucerne chaff (LUC), or (iii) a diet formulated to have a similar digestible energy and BCAA content as CON + LUC (SIMLUC 1) until farrowing. The LUC and SIMLUC 1 diets improved day 21 litter weight (p = 0.055). In Experiment 2 primiparous (n = 111) and multiparous sows (parities 2–5, n = 112) were fed either the CON or SIMLUC diet (SIMLUC 2) from day 110 of gestation to farrowing (PreF), or to day 10 post-farrowing (PreF + PostF). The SIMLUC 2 diet tended to be more beneficial to primiparous compared to multiparous sows when fed PreF, as indicated by an interaction between diet and parity on day 21 average piglet weights (p = 0.078). Overall, SIMLUC is most effective in improving primiparous progeny performance as evidenced by their D21 weights.

The aim of the study was to investigate if the application of a synthetic olfactory agonist (SOA) would reduce indicators of stress in sows, in response to a stressor prior to parturition, and if it would improve farrowing house performance of sows and their piglets. Two studies were conducted: an intensive study with 47 sows, either having their first or second litter (Control n = 24, SOA n = 23), and a commercial validation study with 418 sows, either having their first litter or have had multiple litters (Control n = 210, SOA n = 208). Within the intensive study, sows were housed with or without a synthetic olfactory agonist suspended in the creep area of the farrowing crate, whereas within the commercial validation study, sows were housed with or without a synthetic olfactory agonist suspended over the adjoining creep area of two farrowing crates. Within the intensive study, despite a discernible increase in cortisol concentration in response to a stressor (snout rope test), cortisol response was not different between treatments (p &gt, 0.05). Farrowing duration in first-litter sows exposed to the SOA was decreased (p &lt, 0.001) whilst there was no impact on farrowing duration in second litter sows. Piglets were not attracted by the SOA to increase their utilisation of the creep area and spent more time in proximity to the sow (p &lt, 0.05). Within the commercial validation study, no impacts were seen on piglet production measures (p &gt, 0.05). Largely the use of an SOA within the farrowing house did not impact the sow or her piglets in either the intensive study or commercial validation study. Based on these current results, the use of SOA within the farrowing house is not supported.

The aim of this experiment was to determine whether administration of an anti-inflammatory compound to sows prior to farrowing would, via reduced pain and inflammation, increase piglet survival and growth. At day 114 of gestation, multiparous sows were randomly allocated to one of the following treatments: Control (n = 43), which received 10 mL saline, NSAID (n = 55) which received 0.4 mg/kg meloxicam and SAID (n = 54) which received 0.1 mg/kg dexamethasone. Treatments were applied again on day 116 if farrowing had not occurred. There was no treatment effect on piglets born alive or dead from parity two to four sows but in those of parity five and older, NSAID administration reduced the number of piglets born alive and increased the number of piglets born dead (p &lt, 0.05). Sow rectal temperature and incidence of mastitis were unaffected by treatment (p &gt, 0.05). Lactation day two plasma concentrations of cortisol, prostaglandin F2 alpha metabolite and haptoglobin did not differ among treatments (p &gt, 0.05). Treatment effects were not observed in liveborn piglet mortality at any age, or litter weight at day 21 (p &gt, 0.05). Average feed intake during lactation was increased by both NSAID and SAID treatments (p = 0.001). The use of meloxicam prior to farrowing should be avoided as it reduced the number of piglets born alive and did not improve piglet survival and growth.

It is known that gilt progeny performance is reduced compared with sow progeny. Previous research suggests that the presence of maternal feces in early life improves the health and survival of offspring. Therefore, we aimed to determine whether contact with feces from multiparous (MP) sows would improve the growth and survival of piglets born and reared on primiparous (P1) sows and if so, whether these differences are associated with the gut microbiota. Four treatments were applied for 10 days: Donor (n = 29) piglets had limited access to maternal feces as, each morning, sow feces were removed and placed in the crate of a P1 sow (P1-FT; n = 30 piglets) and P1-Con (n = 29) and MP-Con (n = 33) piglets had access to their own mothers’ feces. All piglets were weighed on days 1, 3, 10, and 18. Fecal samples were collected from a subset of sows (n = 10/treatment) 3 days post farrow and from two female piglets/litter on days 10 and 18 (n = 20/treatment) and subject to 16S rRNA amplicon analysis. Escherichia, Clostridium, Campylobacter, and Treponema were more abundant in MP sows, while P1 sows had a higher abundance of Lactobacillus and Prevotella. At 10 days, P1 progeny fecal microbiota differed, and growth and survival were reduced when compared with MP progeny. No treatment effect was observed for P1-FT piglets (P > 0.05). Donor piglets had a different fecal microbiota and improved weight and survival then all other treatments (P < 0.05). Overall, the removal of sow feces from the farrowing crate improved piglet microbiota development, growth, and survival.

Initial enteric microbial colonisation influences animal health and disease, hence an understanding of the first microbial colonisers within the piglet is important. The spiral colon of piglets that were stillborn (n = 20), born-alive (n = 10), and born alive and had sucked (n = 9) were collected from 28 sows to investigate whether initial microbial colonisation occurs pre- or post-partum and how it develops during the first 24 h post-partum. To examine this, DNA was extracted and 16S rRNA amplicon analysis was performed to allow analysis of microbial communities. The results indicate that microbial colonisation of the spiral colon had occurred in stillborn pigs, suggesting microbial exposure prior to birth. Alpha diversity metrics indicated that the number of taxa and community richness were higher in piglets that sucked (p < 0.001) and community evenness was lower in stillborns in comparison to born-alive (p < 0.001) but was not affected by colostrum consumption (p < 0.001). Additionally, when compared with stillborn piglets, the bacteria colonising the spiral colon during the first 24 h post-partum included the potentially pathogenic bacteria Escherichia coli, Clostridium perfringens and Clostridium celatum, and potentially beneficial bacteria Lactobacillus reutueri and Faecalibacterium prausnitzii. The relative presence of Archaea was high in stillborn piglets but decreased with post-natal environmental exposure. It is evident that stillborn piglets have bacteria present within their spiral colon, however further studies are needed in order to determine the time at which colonisation is initiated and the mechanisms determining how colonisation occurs. Additionally, as expected, the immediate post-natal environment largely influences the microorganisms colonising, while colostrum consumption further contributes to the microbial community enrichment.

Sows are strongly driven to build a nest prior to farrowing, and the performance of this behaviour is linked to the environment in which the animal is housed. The aim of this study was to investigate the impact of two nest-building materials, hessian and straw, on peri-parturient sow behaviour, plasma cortisol concentration and piglet survival and performance in farrowing crates. In the first experiment, sows (parity 1.7 ± 0.1) were allocated to four treatments: (n = 15), straw provided in the lead up to farrowing in an open farrowing pen, with the pen closed after farrowing (STRAW OPEN); (n = 14), straw provided in the lead up to farrowing in a closed farrowing pen (STRAW CLOSED); (n = 15), a closed farrowing pen with hessian sacks provided in the lead up to farrowing (HESSIAN) and; (n = 13), a closed farrowing pen with no nesting materials provided (CONTROL). A second experiment was performed on a separate farm to assess the effect of the same four treatments were applied to sows (parity 2.9 ± 0.1): SRAW OPEN (n = 68), STRAW CLOSED (n = 64), HESSIAN (n = 66) and CONTROL (n = 66), at a commercial level. The first experiment revealed that providing conventionally housed sows with straw or hessian in the lead up to parturition stimulated sows to perform nest-building behaviours similar to sows housed in an open pen with access to straw (nosing events; 16 ± 11 (CONTROL); 169 ± 36 (HESSIAN); 118 ± 29 (STRAW CLOSED); 199 ± 53 (STRAW OPEN); P < 0.05). Additionally, crated sows provided with straw had reduced cortisol levels immediately after farrowing compared to all other treatments (21.9 ± 6.1 ng/ml vs CONTROL; 49.3 ± 8.6 ng/ml; P < 0.01). Piglets born to STRAW CLOSED sows displayed the highest colostrum intake levels (404.8 ± 22.7 g vs CONTROL 361.9 ± 21.9 g; P < 0.01). The second experiment demonstrated a reduced incidence of piglet mortality both prior to fostering (0.7 ± 0.2; P = 0.001) and after fostering (0.7 ± 0.2; P = 0.001) in litters born to sows which were housed in conventional farrowing crates and provided with straw compared to CONTROL (prior to fostering 1.3 ± 0.2, and postfostering 1.1 ± 0.2). In conclusion, straw and hessian sacks are a suitable substrate for stimulating sows to exhibit nest-building behaviour under crated conditions. However, only the provision of straw in the crate environment improved piglet survival and positively affected sow welfare.

The ability to accurately estimate fat mass and fat-free mass (FFM) has the potential to improve the way in which sow body condition can be managed in a breeding herd. Bioelectrical impedance spectroscopy (BIS) has been evaluated as a practical technique for assessment of body composition in several livestock species, but similar work is lacking in sows. Bioelectrical impedance uses population-specific algorithms that require values for the apparent resistivities of body fluids and body proportion factors. This study comprised three major aims: (i) to derive apparent resistivity coefficients for extracellular water (ECW) and intracellular water (ICW) required for validation of BIS predictions of total body water (TBW) in live sows against standard reference tracer dilution methods; (ii) to develop predictions of TBW to body composition prediction algorithms, namely FFM, by developing a body geometry correction factor (Kb) and (iii) to compare the BIS predictions of FFM against existing impedance predictors and published prediction equations for use in sows, based on physical measurements of back-fat depth and BW (P2-based predictors). Whole body impedance measurements and the determination of TBW by deuterium dilution and ECW by bromide dilution were performed on 40 Large White x Landrace sows. Mean apparent resistivity coefficients of body fluids were 431.1 Ω.cm for ECW and 1827.8 Ω.cm for ICW. Using these coefficients, TBW and ECW were over-estimated by 6.5 and 3.3%, respectively, compared to measured reference values, although these differences were not statistically different (P > 0.05). Mean Kb was 1.09 ± 0.14. Fat-free mass predictions were 194.9 kg, which equates to 60.9% of total sow weight, and 183.0 kg for BIS and the deuterium dilution method, respectively. Mean differences between the predicted and measured FFM values ranged from − 8.2 to 32.7%, but were not statistically different (P > 0.05). Method validation (leave-one-out procedure) revealed that mean differences between predicted and measured values were not statistically significant (P > 0.05). Of the impedance-based predictors, equivalence testing revealed that BIS displayed the lowest test bias of 11.9 kg (8.2%), although the P2-based prediction equations exhibited the lowest bias and percentage equivalence, with narrow limits of agreement. Results indicate although differences between mean predicted and measured values were not significantly different, relatively wide limits of agreement suggest BIS as an impractical option for assessing body composition in individual sows compared to the use of existing prediction equations based on BW and back fat.

There are sex differences in behaviour with males tending to be more aggressive and less fearful than females. When females are treated with androgens they display more aggressive, male like, behaviours and this suggests that androgen exposure has a role in the development of aggression. Female pigs born into litters that are more than 60% male (male biased) are likely exposed to greater androgen concentrations in utero than female pigs born into litters that are greater than 60% female (female biased). We hypothesise that the proportion of males in the litter in utero affects female pig behaviour. We predict that gilts from male biased litters will be more aggressive and less anxious than gilts from female biased litters. The behaviour of females from male biased (n = 24) and female biased (n = 30) litters was assessed at day 11 and day 21 of life with an arena test, at weaning (28 days of life) by assessing fight number and duration as well as injury scores and at 16 weeks of age with a resident intruder test. In the day 21 arena test, the pigs from female biased litters took longer to emerge into the arena than pigs from male biased litters (1.13 ± 0.05 (42.2 s) vs. 1.32 ± 0.09 (15.5 s) respectively, P = 0.016). At weaning there was a higher scratch score for piglets from male biased litter (0.84 ± 0.2 vs 0.69 ± 0.15, P = 0.015) and this continued as a trend on the day following weaning (1.76 ± 0.10 vs 1.57 ± 0.13, P = 0.080). At 16 weeks of age in the resident intruder test 48% of gilts from male biased litters initiated a fight compared to 24% of gilts from female biased litters (P = 0.08). Our data suggest that the sex ratio of the birth litter can affect behaviour of gilts, potentially having long term implications for sow aggression.

This study tested whether a gradual reduction in sow contact during lactation, achieved through housing the sow in a ‘sow only’ area, would influence piglet stress responses to weaning. Gradual reduction in sow contact was achieved by separating the sow from her piglets (SP, n = 30) for 5, 7, and 9 h per day on days 10–15, 16–20 and 20 to weaning, respectively. Litters from 20 sows were followed as controls (CON), remaining in full contact with one another until weaning. Weaning occurred on day 28 ± 1.3 of lactation. Piglet body weight, injury scores and evidence of creep ingestion were measured throughout lactation and after weaning. Continuous video footage was collected for 6 h on the days following weaning for behavioural analyses. After weaning, SP piglets were lighter than CON piglets (6.8 ± 0.22 versus 7.6 ± 0.16 kg); however, by day 7 post-weaning piglet weights were similar (P > 0.05) for the CON (8.6 ± 0.22 kg) and SP (8.4 ± 0.15 kg) treatments, possibly reflecting a reduced growth check in SP piglets. There was a significant effect of treatment (CON versus SP) on the duration of aggressive (6.5 ± 1.1 versus 4.2 ± 0.8 s) and belly nosing (6.3 ± 2.0 versus 2.4 ± 1.3 s) events post-weaning. Injury scores were higher for CON piglets on almost all days examined (P

Chronic stress response in fearful animals can result in depression of growth and reproductive performance. It is therefore important to be aware of at risk animals in the herd. Thus far ‘hierarchy’ calculations have involved the use of fights won and lost on the day of mixing or successful displacements over a trial period, or a combination, but not analysis of the two separately and then combined. This experiment used 132, multiparous, Large White x Landrace sows. Following artificial insemination, sows were mixed into groups of 6, for 5 days. Salivary cortisol and behaviour were measured on the day before mixing (d-1) and after mixing d0, d1, d3 and d4. ‘Hierarchy’ was assessed using the number of successful displacements for each sow over all 4 days and the number of fights won and lost on the day of mixing. For both parameters, the sows were separated into three groups, 1D or 1F sows were involved in no fights or displacements, 2D and 2F sows lost more than they won and 3D and 3F sows won more than they lost. Sows ranked 1D1F received significantly more aggression [P

Synthetic olfactory agonists mimic odours secreted by mammary glands in several mammal species and their application can reduce anxiety levels in both juvenile and adult animals. This investigation determined the effect of a commercially available synthetic olfactory agonist administration on behaviour, salivary cortisol secretion and level of injury after sows were mixed into groups. Within five days of mating sows were divided between two treatments according to parity: 24 control sows (CON), and 24 that received the synthetic olfactory agonist (SOA) by being housed with diffusing blocks. Sows were mixed in groups of six, with two replicate pens contained within each of the two rooms, allocated a space allowance of 2.4m 2 and offered 2.7kg/day of a dry sow diet. Sow behaviour, injury counts and saliva samples were collected on days 0, 1, 3 and 7 following the mixing event. In the afternoon of day 7, the SOA diffusing blocks were removed and measurements were collected again on days 8 and 14. On day 0, the mean±SEM log 10 average number of aggressive events recorded per sow was reduced in the SOA (1.0±0.08; back-transformed mean 10.6 events) when compared with CON treatment (0.8±0.08; 5.9 events; P 0.05). Sows were also observed to rest for a log 10 longer duration in the SOA treatment than in CON (4.14±0.02; 230.1min versus 4.10±0.02; 209.8min respectively; P 0.05). After the diffusing blocks were removed from the SOA treatment, a rise in aggression was detected in SOA (2.2±1.1 events per sow) but not CON sows (0.38±1.0 events per sow; P 0.05). These findings support the hypothesis that the provision of a synthetic olfactory agonist can reduce aggression in adult sows at mixing, providing a novel strategy to improve the welfare of group housed sows.

In this experiment, we proposed two hypotheses: birth weight variation would increase in litters from sows bred in summer, and dextrose supplementation during the wean to mate period would ameliorate this manifestation of seasonal infertility. Five hundred and ninety-one multiparous sows were allocated to Control, standard diet, or Dextrose, control +5% dextrose diets from weaning until insemination during summer and winter. Dextrose sows farrowed 1.0 and 1.4 more total pigs born and pigs born alive than Control sows, respectively (p &lt, 0.05). There was a tendency for a higher co-efficient of variation (CV) birth weight in summer than winter (16.6 &plusmn, 0.4 versus 15.8 &plusmn, 0.4, p = 0.1), but no effect of treatment or interaction between treatment and season was observed. Piglet average daily gain was unaffected in those born to sows bred in summer, but when born to sows bred in winter, Dextrose piglets grew 23 g per day faster than Control (p &lt, 0.05). This experiment identified evidence for increased birth weight CV in sows bred during the summer months despite the reduced litter size, suggesting that this is another way seasonal infertility can manifest.

Simple Summary Piglets that experience a long labour are more likely to die during birth or immediately following birth, or to grow slowly during life. This is because the longer the piglet experiences contractions during labour, blood supply and oxygen delivery to the brain will be impaired. Even before the first piglet in the litter is born, sows that will have a delayed labour can be identified. This means that the key to saving piglets that are at risk of death because of long labours lies in managing the sow before she gives birth. Abstract The transition from an intra- to extrauterine existence is extremely challenging for the pig. This is evidenced by the fact that conservative estimates place intrapartum piglet death at between 5% and 10%. The main cause of this loss is the parturition process itself, with a long farrowing duration resulting in reduced oxygenation to the piglet via uterine contractions stretching, and in some cases, causing rupture of the umbilical cord. Sows that experience a long expulsive stage of parturition are likely compromised before the birth of the first piglet, and so any strategy to reduce stillbirth should be applied before this. Even in piglets born alive, 15% to 20% will have suffered asphyxiation because of a long cumulative farrowing duration. These individuals are significantly disadvantaged with regards to behavioural progression, colostrum intake, growth and survival extending past the lactation phase, and so require more labour and resources than littermates in order to make them viable. Given these immediate and longer-term impacts, identifying ways to correctly manage the sow before parturition leading to a reduction in farrowing duration should be a priority in order to maximise piglet performance.

When sows are mixed into groups, hierarchies form and resulting aggression and stress can affect production and welfare. This study determined the effect of providing point-source materials on aggressive and play behaviors in gestating sows. Large white cross Landrace sows were mixed after insemination, six pens of 12 sows were housed in &lsquo, standard&rsquo, pens, and six pens of 12 sows were housed in &lsquo, enhanced&rsquo, pens. The &lsquo, pens each contained two rubber mats, eight strands of 24 mm-thick sisal rope and two yellow plastic disks, suspended from the roof. The sows remained in these pens until pregnancy confirmation. Salivary cortisol concentration, injury counts, and sow behaviors were recorded the day before mixing (day 1), mixing (day 0) and post-mixing day 1, day 4, day 7 and day 20. At farrowing, reproductive outcomes were obtained. Play was observed (including locomotor and object play) in the &lsquo, pen, and percentage of time spent playing was greater on d4 (1.48 &plusmn, 0.3 Square root transformed data (2.84% non-transformed adjusted mean) ), d7 (1.43 &plusmn, 0.3 (2.97%)) and d20 (1.64 &plusmn, 0.3 (3.84%)), compared to d0 (0.56 &plusmn, 0.3 (0.70%)) and d1 (0.87 &plusmn, 0.3 (1.67%) (p &lt, 0.05) ). No play was observed in standard housing. Aggression, salivary free cortisol concentrations and injuries were unaffected (p &gt, 0.05). The provision of materials had no impact on aggression, although their presence maintained sow interest and play behavior, suggesting a positive effect.

The aim of this study was to investigate the effect of sow confinement and nonconfinement during parturition and early lactation on the performance of sows and piglets prior to weaning. Sows and their litters were housed in either a conventional farrowing crate (control; 1.7 × 2.4 m) or a swing-sided pen (2.8 × 2.15 m). Sows housed in the swing-sided pen had the crate open (open) or closed (closed) during farrowing and opened on d 3 (LAC3) or 7 (LAC7) of lactation. Data are means ± SEM. The numbers of total and live-born piglets were not different between treatments and averaged 13.1 ± 0.4 and 12.3 ± 0.2 piglets/litter, respectively. Sows housed in a farrowing crate had a greater ( = 0.03) number of stillborn piglets compared with open sows from pens (1.1 ± 0.2 vs. 0.6 ± 0.1 piglets/litter, respectively). Live-born piglet mortality before litter equalization on d 1 was greater ( 0.05). Total live-born piglet mortality from birth until weaning for the control, closedLAC7, closedLAC3, openLAC7, and openLAC3 was 1.86 ± 0.19, 1.95 ± 0.23, 2.10 ± 0.39, 2.45 ± 0.27, and 3.74 ± 0.48, piglets/litter, respectively. Total live-born piglet mortality from birth until weaning was greater in the openLAC3 and openLAC7 treatments compared to control ( < 0.01), and openLAC3 was also greater than openLAC7, closedLAC3, and closedLAC7 ( < 0.01). The current data indicated that reducing sow confinement during parturition decreased stillborn number but increased live-born piglet mortality compared to a farrowing crate, and removing confinement on d 3 of lactation further increased total piglet mortality compared to removing sow confinement on d 7 of lactation in sows that farrowed open. Sows that were confined during farrowing and until d 3 or 7 of lactation in a swing-sided pen had a similar piglet mortality compared to those in a farrowing crate.

Aggression between domestic sows is greatest when sows are first introduced to each other and hierarchies form. The aim of this study was to determine the effect of a spacious "mixing pen" on sow aggression and stress. Sows were mixed into groups of 6 and allowed 2 (LOW; 8 groups and 48 sows), 4 (MED; 7 groups and 42 sows), or 6 m/sow (HIGH; 7 groups and 42 sows) for 4 d after mixing, at which point all pens were equalized to 2 m/sow. Salivary cortisol concentration and injury counts were measured on d -1, 0, 1, 3, and 4 relative to mixing, and behavior was also recorded on each of these days following mixing. Reproductive performance was assessed at farrowing. A linear mixed model was applied to the data. Data are presented as least squares means and standard error of the mean. Where transformations occurred, nontransformed adjusted means are presented in parentheses following the presentation of transformed data. In the primary analyses where measures were considered at the pen level, there were no effect of space allowance on fight number per sow, duration of fights, percentage of total time spent fighting, displacements, bites, knocks, and lunges ( > 0.05). These measures were higher on d 0 (i.e., fight number 1.0 ± 0.1 [13.8]) compared with d 1 (0.4 ± 0.1 [4.2]), 3 (0.7 ± 0.1 [5.3]), and 4 (0.7 ± 0.1 [5.5]; 0.05). There was increased percentage of time spent active (1.5 ± 0.02 [33.7] for LOW, 1.5 ± 0.02 [36.5] for MED, and 1.6 ± 0.02 [43.4] for HIGH) and time spent exploring (1.8 ± 0.1 [3.5] for LOW, 2.0 ± 0.1 [4.0] for MED, and 2.3 ± 0.1 [5.7] for HIGH) and number of nonaggressive sow-sow contacts (0.3 ± 0.09 [2.2] for LOW, 0.4 ± 0.07 [3.2] for MED, and 0.5 ± 0.07 [4.5] for HIGH) in HIGH compared with LOW ( 0.05). A secondary analysis was conducted that examined individual sow behavior within each pen, and this identified increased injury number in the lowest ranked sows (involved in no fights on d 0 and no displacements on d0 to d4) in LOW (9.3 ± 1.2 [107.9] for LOW, 6.2 ± 0.8 [53.0] for MED, and 5.1 ± 0.8 [28.1] for HIGH) and also decreased fight number and duration in HIGH compared with LOW on d 0 and 1 ( < 0.05). Our primary data analysis demonstrates positive exploratory and social behaviors with increased space and suggests that a reduction in space following hierarchy formation is not a significant stressor. Additionally, there is some evidence at an individual sow level that increased space at mixing benefits sow welfare parameters, especially for low-ranked sows.

There is a considerable gap in available literature regarding the use of prepartum steroidal anti-inflammatory drugs (SAIDs) despite their ability to provide a targeted response to pain. The aim of this investigation was to determine whether prepartum administration of dexamethasone to sows would influence farrowing and/or lactation processes, with the prediction that it would affect both sow and piglet performance. Sows were induced to farrow on day 113 of gestation (2 days before their 115 day due date) and were treated with dexamethasone concurrent with induction (DexInd; n = 20), 24 h after induction (Dex24; n = 20), at induction and 24 h later (Dextwice; n = 19) or no steroid treatment (Control; n = 20). Treating with dexamethasone at induction reduced birth and weaning weights (P = 0.001), plasma total protein concentrations (P = 0.001), and colostrum intake of piglets of multiparous sows (P = 0.006). Treating with dexamethasone 24 h after induction did not adversely affect piglet weights or plasma total protein and improved average daily gain in piglets (P = 0.001). Although no differences were observed for farrowing duration or piglet survival (P > 0.05), further investigation is required using higher parity sows to qualify whether glucocorticoids can improve farrowing performance.

Antimicrobial use in animals and the potential development of antimicrobial resistance is a global concern. So, non-antimicrobial techniques for animal disease control are needed. This study aimed to determine whether neonatal ceftiofur (CF) treatment affects piglet faecal microbiomes and whether faecal microbiome transplantation (FMT) can correct it. Two focal piglets per sow were assigned to treatments as follows: cffresh (n = 6) received CF (3 mg/kg intramuscular) at 7 d and fresh FMT at 13 d, cffrozen (n = 7) received CF at 7 d and frozen FMT at 13 d, CF (n = 8) received CF at 7 d and no FMT, and no CF (n = 5) received no CF or FMT. DNA was extracted from faecal samples collected on days 7, 13, and 18 for 16S rRNA amplicon analysis. All faecal blends used for the FMT consisted of pooled donor pig faeces at 1:2 ratio with saline, delivered orally at 3 mL/kg. Alpha and beta diversity metrics increased with age (p &lt, 0.05). However, no effect of antibiotic or FMT treatment was evident in 13 and 18 d old piglets (p &gt, 0.05). Although no effect of treatment was observed, information regarding microbial membership during lactation was gained.

Piglet hypoxia during farrowing is common and can lead to increased stillbirth rates, reduced piglet vitality, and an increased risk of preweaning mortality. Magnesium sulfate (MgSO4) has successfully been used as a neuroprotectant and readily crosses the placenta in humans. Based on this human data, the aim of this study was to determine if maternal dietary supplementation with MgSO4 prior to farrowing would reduce the impact of piglet hypoxia during the peri-natal period. Five days prior to farrowing, Large White &times, Landrace sows were fed either standard lactation sow diet (Cont, n = 30) or lactation diet supplemented to deliver 21 g/day MgSO4 (Mg, n = 31). There was no effect of treatment on the percentage of stillborn piglets (p &gt, 0.05). However, Mg piglets tended to have higher vitality scores immediately after birth (p &lt, 0.10), were quicker to suck, and had higher day one blood glucose concentrations when compared with Cont piglets (p &lt, 0.05). Furthermore, hypoxic piglets born to Cont sows did not gain weight from birth to 24 h, but Mg piglets did (p &lt, 0.05), suggesting improved colostrum ingestion. In conclusion, MgSO4 may reduce the negative impacts of birth hypoxia, improving piglet vitality, and colostrum intake during the peri-natal period.

To reduce piglet mortality from overlay, farrowing crates confine the sow, restricting nest building activities. The aim of this study was to investigate the impact of confinement in the lead up to and during parturition on sow and litter characteristics. Sows (parity 1.6 ± 0.1) were housed in pens the size of a traditional crate with bars that allowed for temporary confinement. Two treatments were applied; OPEN (n = 36): pen was open until the sow stood following parturition, at which point they were closed, and CLOSED (n = 34): pen was closed through parturition. At d 10 of lactation the pens were opened for both treatments. A subset of sows (n = 12 CLOSED, n = 14 OPEN) were observed remotely during parturition and 18 h after parturition for behavioural analyses. Blood samples were collected hourly from −24 h until farrowing completion, and again at 24 h post farrowing. Piglet weights were collected at birth, 24 h and at weaning. OPEN sows displayed a reduced incidence of pain-related behaviours including tail flicks (8.4 ± 0.7 vs 27.6 ± 1.5; P 0.05). Sows from OPEN pens gave birth to fewer stillborn piglets than CLOSED (0.2 ± 0.1 vs 0.4 ± 0.1 piglets/litter respectively; P

Simple Summary The aim of this project was to review previously published research with a focus on the effects of farrowing accommodation on piglet performance. The specific design features were analysed to determine whether animals in loose housed farrowing pens or crates from loading to weaning contribute to differences in litter performance obtained from different farrowing house accommodation types. This was the first systematic review and meta-analysis conducted towards the farrowing performance of crates and pens. The relative risk of piglet mortality was 14% higher in farrowing pens than farrowing crates, which indicated that non-confinement of sows compromises post-natal piglet survival. Overall, the type of farrowing accommodation did not affect the number of stillborn piglets. However, the rate of stillborn piglets was lower in farrowing pens that were not enriched when compared with farrowing crates, also with no enrichment. There was no effect of housing type on the number of piglets born alive or the number of piglets weaned, although the sample size for the later was much smaller. Producers should anticipate an increase in mortality when piglets are reared by sows that are unconfined in the pen designs that are currently available, which supports the wider belief that crates are successful for reducing pre-weaning piglet mortality. Abstract There are conflicting reports regarding the effect of farrowing house accommodation on piglet performance. The aim of this investigation was to use a systematic review and meta-analyses to summarise the results of publications that focused on direct comparisons between full confinement conventional crates and various designs of loose-housed farrowing pens from loading until weaning. Literature searches in Scopus, BIOSIS Previews, Cab Abstracts, and Web of Science identified 6695 articles. Twenty-two publications were retained for the systematic review and individual meta-analyses after screening for inclusion criteria. The random effects meta-analyses were performed on crate versus pen for number of piglets born alive, number of stillborn piglets, pre-weaning mortality, and number of piglets weaned. Additionally, the modifiers of confinement length (no confinement from loading until weaning or partial confinement for shorter periods of time in the early stages post parturition), enrichment (no enrichment or enrichment provided), and pen size (small, medium, or large) were examined. There was a 14% increase in the relative risk of piglet mortality in farrowing pens when they were compared with crates (p = 0.0015). The number of stillborns per litter was not different between the pen and crate. However, when providing enrichment in the pens, there was an increase in stillborns within farrowing crates versus pens (p = 0.009). There was no overall effect on piglets that were born alive or number weaned. As there is no difference between piglets born alive and mortality is significantly higher in farrowing pens, a reduction in the number of piglets weaned was expected but not observed, which was possibly due to the lack of weaning details provided in the publications. This was the first systematic review and meta-analysis conducted on the performance of farrowing accommodation and identified that farrowing pens do compromise post-natal piglet survival. Future efforts should focus on improving sow comfort in the farrowing crate to maximize both piglet and sow welfare.

The aim of this study was to evaluate the effects of parity and space allowance on selected measures indicative of welfare, and on reproductive parameters, in group-housed sows. Selected animals were at first parity or parity three or greater, and were housed with allocated space allowances per pig of 1.4 or 2.8 m 2 . Welfare outcome measures included: injury and lameness scores, plasma cortisol levels, neutrophil:lymphocyte ratios and reproductive performance. These values were recorded at a range of timepoints in the first 24 h after mixing, and at 28 days after the mixing event. In general there were few significant effects of space allowance and parity level on the measured outcomes. However, improved reproduction, as evidenced by increased litter size and born alive figures, was seen as a result of increased space allowance in older animals. A contrary response was observed in gilts. Cortisol responses also indicated that there was a rapid habituation to the stress of mixing with levels returning to baseline within 24 h. Cortisol levels remained low in older animals but unexpectedly showed a peak at 28 days in gilts. It is postulated that this may have arisen as a result of handling events associated with pregnancy testing. Our results suggest that at least at the chosen stocking densities, parity and space allocation have minimal effect on a number of commonly-used welfare measures.

Factors that have been shown to impact the welfare of group-housed sows are discussed in this review. Floor space allowance markedly affects sow welfare. In addition to quantity of floor space, the quality of space is important: spatial separation between sows can be provided with visual or physical barriers and stalls. Whereas 1.4 m/sow is insufficient, further research is required to examine space effects in the range of 1.8 to 2.4 m/sow in more detail. The period immediately after mixing has the most pronounced effects on aggression and stress, and therefore, well-designed mixing pens offer the opportunity to reduce aggression, injury, and stress while allowing the social hierarchy to quickly form. Because hunger is likely to lead to competition for feed or access to feeding areas, strategies to reduce hunger between meals through higher feeding levels, dietary fiber, or foraging substrate should be examined. However, feeding systems, such as full-body feeding stalls, can also affect aggression and stress by providing protection at feeding, but deriving conclusions on this topic is difficult because research directly comparing floor feeding, feeding stalls, and electronic sow feeder systems has not been conducted. Familiar sows engage in less aggression, so mixing sows that have been housed together in the previous gestation may reduce aggression. Although there is evidence in other species that early experience may affect social skills later in life, there are few studies on the effects of early "socialization" on aggressive behavior of adult sows. Genetic selection has the potential to reduce aggression, and therefore, continued research on the opportunity to genetically select against aggressiveness and its broader implications is required. Most research to date has examined mixing sows after insemination and knowledge on grouping after weaning is limited.

Aggression is at its highest when sows are first introduced to new animals and hierarchies are being established. Thus, methods to reduce aggression should focus on this period. The aggression that occurs during mixing results in physiological stress responses, which can have detrimental effects on sow welfare and reproductive parameters. In pigs, the short-term nature of this response means that these effects can be avoided with careful management. Many attempted aggression management techniques, such as sedation and boar presence, only lead to short term reduction of aggression at mixing. Other methods, such as high space allocation at mixing, same parity mixes and small group sizes, highlight that simple factors can reduce aggression, but optimum management has not yet been determined. The objectives of future studies should be to isolate the techniques which can be practically managed on commercial farms and aim to provide further and conclusive information on optimum mixing management. In the interim, management techniques such as providing as much space as practical at mixing and reducing the number of limiting resources can be implemented, until optimum management techniques can be defined.

This study investigated the effects of providing lucerne hay on the behaviour and the performance of sows housed in farrowing crates during farrowing and lactation. Seventy-two mixed parity sows received either 1 kg lucerne hay daily from entry into the farrowing crate (&minus, 2 d from expected farrowing date) until weaning at 17 d (lucerne group, n = 36), or received no additional enrichment (control group, n = 36). In the 18 h prior to farrowing, the sows in the lucerne treatment spent more time performing nest-building behaviour (14.8% lucerne vs 11.1% control, p = 0.0009) and less time sham-chewing (1.0% lucerne vs 1.9% control, p = 0.01) than control sows, and gave birth to fewer stillborn piglets/litter (0.1 lucerne vs 0.4 control, p = 0.027). After farrowing (Day 3), the control sows spent less time lying than the lucerne sows (26% control vs 43% lucerne, p &lt, 0.05). The control sows also spent less time interacting with their piglets during early lactation compared to late lactation (25.5% Day 5 vs 47.3% Day 12, p &lt, 0.05), suggesting reduced maternal behaviour in this group. The lucerne sows continued to interact with the lucerne throughout lactation, indicating that they still found the enrichment rewarding after the nesting period had ceased. Based on these results, lucerne enrichment was considered to improve sow welfare during farrowing and lactation and reduce the number of stillborn piglets.

Simple Summary Piglet preweaning mortality is a major economic loss and welfare concern for the global pork industry, with the industry average sitting at approximately 15%. As such, novel methods for reducing this mortality are needed. Since research into the intestinal microbiota has provided advances in human health, in particular the impact of early life factors, it was the logical next step to synthesise the existing literature to determine the potential relevance to the pig industry. It is evident from the literature that this area of research provides promising results. However, a large gap within the literature currently exists within the lactation period in pigs. Since optimal development within early life is proving to be critical for human infants, it is crucial that further research is invested into understanding the impact of early life events on a piglet’s microbiome. It is hoped that this review will enable access to critical information for those interested in the microbiome and its potential for improving herd health on the farm. Abstract The intestinal microbiota has received a lot of attention in recent times due to its essential role in the immune system development and function. Recent work in humans has demonstrated that the first year of life is the most critical time period for microbiome development with perturbations during this time being proven to have long term health consequences. In this review, we describe the literature surrounding early life events in humans and mice that contribute to intestinal microbiota development and function, and compare this to piglets predominantly during their lactation period, which focuses on the impact lactation management practices may have on the intestinal microbiota. Although extensive research has been conducted in this area in humans and mice, little research exists in pigs during perceivably the most critical time period of development, which is the lactation period. The research reviewed outlines the importance of appropriate intestinal microbiota development. However, further research is needed in order to understand the full extent routine farm practices have on a piglet’s intestinal microbiota.

Investigations were made into the genetics of several temperament traits in Merino ewes, with particular emphasis on those aspects which might be associated with maternal behaviour at lambing and consequently, the postnatal survival of lambs. If a beneficial relationship between ewe temperament and lamb survival could be established, indirect selection for such a trait may result in increased gain in survival when compared to direct selection. Ewe mothering temperament was a subjective score based on the proximity of the ewe whilst her lamb was tagged and measured the ewes affinity to her lamb, agitation score measured the reactivity of a sheep whilst isolated from flock mates and lastly, flight time calculated the time taken for a sheep to cross two points 1.7m apart after release from a weight crate reflecting aversion to human handling. A data set from over 118 sires, approximately 2000 animals and more than 20,000 records was analysed for estimation of the genetic parameters for these traits and a set of economically important wool production traits. The heritability (±SE) of ewe mothering temperament was 0.35±0.02. Agitation score and flight time were less heritable (0.20±0.05 and 0.12±0.05, respectively). The heritability of litter survival was low (0.09±0.01) and the genetic correlations between this trait and ewe mothering temperament, agitation score and flight time were 0.18±0.08, 0.39±0.18 and 0.09±0.27, respectively. Estimated genetic correlations ( r g ) between temperament traits and wool traits overall were negligible, with the exception of staple length (wool growth since last shearing) which was negatively correlated to agitation score ( r g =−0.26±0.03). The relationship between agitation score and litter survival is predicted to result in a smaller increase in lamb survival than compared to direct selection for the trait itself. Further, if selection is practised for low agitation score, the observed positive relationship would suggest that litter survival may be reduced in future generations.

The objective of the present study was to compare two common durations of altrenogest (ALT) feeding during different periods of the year on the fertility of gilts after ALT withdrawal. During a 12-month period gilt replacements that were assumed to be cyclic were subjected to oestrus synchronisation with 15 mg/day ALT administered for 18 days (ALT-18; n = 268) or 14 days (ALT-14; n = 153) whereas 275 non-treated gilts served as controls. Fewer ALT-14 than ALT-18 gilts expressed oestrus by 7 days after last ALT treatment (79.1% vs 88.8%; P < 0.05). Farrowing rate was lower (P < 0.05) for ALT-14 than for the other groups (81%, 91% and 92% for ALT-14, ALT-18, and Control, respectively) but farrowing rates were not affected by time of year. Control litter sizes were not different from ALT-14 except during September to November when Control litter sizes were larger than either ALT treatments (13.6 ± 0.33, 12.3 ± 0.65 and 12.7 ± 0.39 for Control, ALT-14 and ALT-18, respectively; P < 0.05). The ALT-18 gilts had larger litter sizes during January to August. The present data suggest that the appropriate duration of ALT feeding to synchronise oestrus in gilts is 18 days.

This experiment investigated whether allopregnanolone, a neurosteroid metabolite from progesterone, modulates the stress response during early pregnancy. Twenty-five nulliparous sows (Sus scrofa) were allocated to one of three treatments: pregnant, ovariectomized or ovariectomized administered daily intravenously with alfaxalone as a synthetic allopregnanolone analog. On days 5, 12 and 19 of pregnancy, all sows were subjected to social stress by submitting them individually to a resident-intruder test, acting as the intruder. Blood samples were collected to analyze plasma progesterone, allopregnanolone, cortisol and adrenocorticotropic hormone (ACTH) concentrations. On day 26, 10 sows across the three treatments were subjected to a dexamethasone suppression test followed by a corticotrophin-releasing hormone administration to test the functionality of their hypothalamo-pituitary-adrenal (HPA) axis through cortisol release. Pregnant sows returned more rapidly to baseline cortisol concentrations following the resident-intruder test (p = 0.006). However, there were no other differences in cortisol or ACTH concentrations according to treatment or day, or to the HPA responsivity test on day 26. Allopregnanolone concentration in pregnant sows was higher than in ovariectomized sows (p 0.001), but stable during the first third of pregnancy. Allopregnanolone concentration was correlated with longer resident-intruder test duration (pregnant: r = 0.66, p = 0.0003; ovariectomized: r = 0.47, p = 0.03), reflecting lower aggressiveness, and with progesterone concentration (r = 0.25, p = 0.03). Alfaxalone administration raised plasma allopregnanolone concentration in alfaxalone-administered sows but resulted in little behavioral and physiological effects. These findings did not support the hypothesis that the stress response of the female pig changes in the first third of pregnancy. Allopregnanolone was associated with lower aggression in social encounters.

Periconceptional nutrition (PCN) can influence foetal hypothalamo-pituitary adrenal (HPA) axis function and alter cortisol secretion with possible consequences for maturation and growth of major organs, gestation length and behaviour. We examined effects of PCN on phenotype and survival of the neonatal lamb in 466 Merino ewes allocated to treatments providing 70%, 100% and 150% respectively, of maintenance requirements for 17 days prior and 6 days after insemination. Gestation length and birth weight for lambs in PCN treatment groups was similar (P > 0.05) but low PCN decreased the size of the neonate (crown-rump-length and metacarpal length P < 0.05). A subset of lambs euthanased at 5 days of age further showed that low PCN decreased the amount of peri-renal fat (P < 0.05) and increased liver mass (P < 0.05) while high PCN increased neck thymus and ovary mass (P < 0.05). Neonatal lambs from low PCN ewes returned faster to their mothers after release (P < 0.05) and contacted the udder in the shortest time (P < 0.05). Significant interactions between PCN treatment and sex (P < 0.05) and between PCN treatment and ewe age (P < 0.05) were also observed for time lambs took to follow the ewe. Survival of lambs was similar but potential differences may have been masked by favourable weather conditions. In conclusion, this study provides evidence of significant changes in lamb growth and development dependent on PCN and, for the first time, links these changes with significant changes in behaviour of the neonate. The impact of these effects on lamb survival and potential reproductive capacity of female offspring remains to be determined.