The responsiveness of sows to their piglets in relation to the length of parturition and the involvement of endogenous opioids

Piglets' behaviour and performance in relation to sow characteristics

The importance of maternal care in commercial pig production is largely ignored. The sow has little possibility to interact with her piglets, and piglets are often subjected to early weaning or artificial rearing. This study aimed to investigate aspects of physiological and behavioural maternal provisioning that contribute to offspring outcomes. We hypothesised that better maternal care and nutritional provisioning would relate positively to piglet immunity, growth and behaviour. Nineteen sows and their litters were studied in free-farrowing pens. Oxytocin and tumour necrosis factor-α in colostrum/milk and salivary cortisol were sampled from sows throughout lactation. Sows were assessed for dominance rank, response to handling, maternal defensiveness, suckling initiation and termination, posture and sow-piglet contact. Piglets were weighed, measured for body mass index (BMI) and sampled for blood (Immunoglobulin G; at birth). After weaning, they experienced a human approach test (HAT) and novel object test. Correlations were explored between individual sow characteristics, individual piglet outcomes, and between sow characteristics and piglet outcomes averaged by litter. Significant correlations between sow and piglet factors were analysed at the litter level in mixed models with piglet outcomes as response variables and sow characteristics as predictor variables, while accounting for sow parity, litter size and batch. Litters grew faster when their sow had lower cortisol values (P = 0.03), while sows with lower cortisol levels had more successful suckling bouts and engaged in greater amounts of sow-piglet contact. Litters had a lower BMI at weaning when the sow had a higher milk fat percentage at d3. Litters of the most dominant sows took longer to approach the human in the HAT, while litters of sows with higher cortisol at d0 took longer to approach the novel object when assessed on correlations (r = 0.82, P < 0.001) but not when the model accounted for parity and litter size (P = 0.35). Only some of the measured nutritive and non-nutritive sow factors influenced litter performance and behaviour, with parity and litter size also playing a role. Given the continued increase in litter size, but also the interest in loose-housed lactation pens for sows, further research on sows' maternal investment and how it can be optimised is warranted.

Analysis of image-based sow activity patterns reveals several associations with piglet survival and early growth

An activity pattern describes variations in activities over time. The objectives of this study are to automatically predict sow activity from computer vision over 11 days peripartum and estimate how sow behavior influences piglet's performance during early lactation. The analysis of video images used the convolutional neural network (CNN) YOLO for sow detection and posture classification of 21 Large White and 22 Meishan primiparous sows housed in individual farrowing pens. A longitudinal analysis and a clustering method were combined to identify groups of sows with a similar activity pattern. Traits under study are as follows: (i) the distribution of time spent daily in different postures and (ii) different activities while standing. Six postures were included along with three classes of standing activities, i.e., eating, drinking, and other, which can be in motion or not and root-pawing or not. They correspond to a postural budget and a standing-activity budget. Groups of sows with similar changes in their budget over the period (D-3 to D-1; D0 and D1-D7) were identified with the k-means clustering method. Next, behavioral traits (time spent daily in each posture, frequency of postural changes) were used as explanatory variables in the Cox proportional hazards model for survival and in the linear model for growth. Piglet survival was influenced by sow behavior on D-1 and during the period D1-D7. Piglets born from sows that were standing and doing an activity other than drinking and eating on D-1 had a 26% lower risk of dying than other piglets. Those born from sows that changed posture more frequently on D1-D7 had a 44% lower risk of dying. The number of postural changes, which illustrate sow restlessness, influenced piglet growth in the three periods. The average daily gain of piglets born from sows that were more restless on D1-D7 and that changed posture more frequently to hide their udder on D0 decreased by 22 and 45 g/d, respectively. Conversely, those born from sows that changed posture more frequently to hide their udder during the period of D1-D7 grew faster (+71 g/d) than the other piglets. Sow restlessness at different time periods influenced piglet performance.

A dynamic concept of animal welfare: The role of appetitive and adverse internal and external factors and the animal’s ability to adapt to them

Animal welfare is a multifaceted issue that can be approached from different viewpoints, depending on human interests, ethical assumptions, and culture. To properly assess, safeguard and promote animal welfare, concepts are needed to serve as guidelines in any context the animal is kept in. Several different welfare concepts have been developed during the last half decade. The Five Freedoms concept has provided the basis for developing animal welfare assessment to date, and the Five Domains concept has guided those responsible for safeguarding animal welfare, while the Quality of Life concept focuses on how the individual perceives its own welfare state. This study proposes a modified and extended version of an earlier animal welfare concept - the Dynamic Animal Welfare Concept (DAWCon). Based on the adaptability of the animal, and taking the importance of positive emotional states and the dynamic nature of animal welfare into account, an individual animal is likely in a positive welfare state when it is mentally and physically capable and possesses the ability and opportunity to react adequately to sporadic or lasting appetitive and adverse internal and external stimuli, events, and conditions. Adequate reactions are elements of an animal’s normal behavior. They allow the animal to cope with and adapt to the demands of the (prevailing) environmental circumstances, enabling it to reach a state that it perceives as positive, i.e., that evokes positive emotions. This paper describes the role of internal as well as external factors in influencing welfare, each of which exerts their effects in a sporadic or lasting manner. Behavior is highlighted as a crucial read-out parameter. As most animals under human care are selected for certain traits that may affect their behavioral repertoire it is crucial to have thorough ethograms, i.e., a catalogue of specific behaviors of the species/strain/breed under study. DAWCon highlights aspects that need to be addressed when assessing welfare and may stimulate future research questions.

Parturition in Mammals: Animal Models, Pain and Distress

Parturition is a complex physiological process and involves many hormonal, morphological, physiological, and behavioural changes. Labour is a crucial moment for numerous species and is usually the most painful experience in females. Contrary to the extensive research in humans, there are limited pain studies associated with the birth process in domestic animals. Nonetheless, awareness of parturition has increased among the public, owners, and the scientific community during recent years. Dystocia is a significant factor that increases the level of parturition pain. It is considered less common in polytocous species because newborns' number and small size might lead to the belief that the parturition process is less painful than in monotocous animal species and humans. This review aims to provide elements of the current knowledge about human labour pain (monotocous species), the relevant contribution of the rat model to human labour pain, and the current clinical and experimental knowledge of parturition pain mechanisms in domestic animals that support the fact that domestic polytocous species also experience pain. Moreover, both for women and domestic animal species, parturition's pain represents a potential welfare concern, and information on pain indicators and the appropriate analgesic therapy are discussed.

Meloxicam and Dexamethasone Administration as Anti-Inflammatory Compounds to Sows Prior to Farrowing Does Not Improve Lactation Performance

Simple Summary

Sows may experience pain and discomfort whilst giving birth. Additionally, the birthing process is accompanied by an inflammation response. Administering anti-inflammatory compounds prior to birth may provide an opportunity to improve piglet survival and growth. The aim of this experiment was to assess the efficacy of both a non-steroidal (NSAID; meloxicam) and steroidal (SAID; dexamethasone) anti-inflammatory drug for improving farrowing house performance of sows. In younger sows, there was no impact of treatment; however, older sows from the NSAID treatment gave birth to fewer live piglets. Postnatal mortality was unaffected by treatment and no improvement in piglet growth was observed. Feed intake of both NSAID and SAID sows was improved when compared with the control group; however, there was a tendency for a delayed oestrus in the NSAID group. Administering NSAID to sows prior to farrowing is not recommended as it reduces piglet survival and subsequent reproduction.

Abstract

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 < 0.05). Sow rectal temperature and incidence of mastitis were unaffected by treatment (p > 0.05). Lactation day two plasma concentrations of cortisol, prostaglandin F2 alpha metabolite and haptoglobin did not differ among treatments (p > 0.05). Treatment effects were not observed in liveborn piglet mortality at any age, or litter weight at day 21 (p > 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.

Isomaltooligosaccharide and Bacillus regulate the duration of farrowing and weaning-estrous interval in sows during the perinatal period by changing the gut microbiota of sows

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus in perinatal diets on the duration of farrowing and post-weaning estrus, serum reproductive hormone concentrations, and gut microbiota and its metabolites of sows. Multiparous sows (n = 130) were fed diets without IMO (control, CON group), or diets containing only IMO (IMO group), IMO and Bacillus subtilis (IMOS group), IMO and Bacillus licheniformis (IMOL group), and IMO and B. subtilis and B. licheniformis (IMOSL group), respectively. The results indicate that the duration of farrowing and post-weaning estrus was shorter in sows in the IMOS, IMOL, and IMOSL groups, and the weaning-estrous interval was lower in sows in the IMOL greoup. In addition, the lowest fecal score was observed in the IMOL group during d 106 to 112 of gestation. Sows in most of the treatment groups had a higher concentration of serum prolactin and prostaglandin at farrowing, but a lower serum concentration of estradiol, oxytocin, and progesterone on d 18 of lactation than sows in the CON group. The treatment groups had a higher abundance of Candidatus Methanoplasma and Bacillus and a lower abundance of Escherichia-Shigella in their feces at farrowing. Furthermore, the treatment groups had higher concentrations of total short-chain fatty acids (SCFA) in feces at farrowing and a higher concentration of branched fatty acids in feces on d 18 of lactation. Furthermore, the abundance of Bacillus in feces was positively correlated with serum prostaglandin concentrations and fecal total SCFA of sows at farrowing, but was negatively correlated with the duration of farrowing. Overall, dietary IMO and Bacillus supplementation affected the concentration of serum reproductive hormones and the duration of farrowing and post-weaning estrus, and the gut microbiota is a key factor.

Effects of heat stress on posture transitions and reproductive performance of primiparous sows during late gestation

This study aimed to investigate the effects of heat stress on posture transitions of perinatal primiparous sows around the parturition period from 72 h prepartum to 24 h postpartum. The reproductive performance of sows was measured, and the relationship between posture transitions and reproductive performance was also analyzed. Ten primiparous sows were randomly assigned to thermoneutral (TN) (18-22 °C; n = 5) or heat stress (HS) (28-32 °C; n = 5) treatments. Posture transitioning, including the frequency of posture change, duration of dynamic posture (DP), and lateral lying with udder to the piglet creep box (PCB) during three periods (72 h prepartum, sub-partum, and 24 h postpartum, respectively), were recorded. Posture change frequency was significantly increased, starting from 24 h prepartum to the onset of farrowing in both the TN (P < 0.05) and HS (P < 0.01) groups. Moreover, the peak value of posture change frequency in the TN group was concentrated during the 12 h prepartum period, positively correlated with the quantities of head-first birth piglets and sub-partum duration, respectively. DP duration increased during the period of 24 h prepartum and then decreased sharply (P < 0.001 and P < 0.05 for TN and HS groups, respectively). The duration of facing the udder to the PCB increased during sub-partum and postpartum TN (P < 0.001). The duration of sub-partum (P < 0.05) and delivery time of single piglets (P < 0.01) in the HS group was prolonged, and piglets from the HS group had a lower weight gain than the TN group both at d10 (P < 0.001) and weaning time (P < 0.001). In conclusion, HS had obvious adverse effects on nursery behavior and reproductive abilities in perinatal primiparous sows, which resulted in poor growth performance of lactating piglets.

[Clinical, ethologic, endokrinologic, and metabolic aspects of the peripartal period in pigs]

The aim of this review article is to provide an overview of the literature relevant to the peripartal period in swine. As in all other mammals, the farrowing process in pigs is divided into 3 phases (I-III; opening, expulsion, and postnatal stage), during which various essential endocrine and metabolic mechanisms initiate or maintain parturition. These include the hormones progesterone, cortisol, prostaglandin F_2α, oxytocin, estradiol, relaxin as well as electrolytes, enzymes, and metabolites such as calcium, magnesium, inorganic phosphate, glucose, creatine kinase, lactate, non-esterified free fatty acids, and β-hydroxybutyrate. Exogenous or endogenous disruptive factors may result in a delay or even stagnation of labor. For example, the form of husbandry may represent a possible exogenous disruptive factor. Endogenous disruptive factors may arise from insufficient storage and/or distribution of the above-mentioned labor-associated parameters. Subsequent dystocia leads to temporary or permanent consequences for maternal reproductive fitness and impairs piglet vitality at the time of birth, possibly resulting in lower survival rates.

Short Communication: effect of positive handling of sows on litter performance and pre-weaning piglet mortality

Fear and environmental stressors may negatively affect the welfare of farm animals such as pigs. The present study investigated the effects of music and positive handling on reproductive performance of sows (n = 1014; parity 1 to 8) from a commercial pig farm practicing a batch farrowing system. Every 2 weeks, 56 sows were moved from the gestation unit to conventional-crated farrowing houses 1 week prior to expected farrowing. Treated (T; n = 299) and control (C; n = 715) sows were included in the study. In the farrowing houses, auditory enrichment (music from a radio) was provided to sows of T groups daily from 0600 to 1800 h until the end of lactation. Until the day of farrowing, T sows were additionally subjected, for 15 s per day per sow, to continuous back scratching by one member of farm staff. Litter performance and piglet mortality were recorded and analysed between T and C sows using linear mixed regression models. The number of liveborn piglets (C 13.85 v. T 13.26) and liveborn corrected for fostering (C 13.85 v. T 13.43) was significantly higher (P < 0.05) in C groups compared to the T groups. The number of stillborn piglets was 0.60 and 0.72 in T and C groups, respectively (P > 0.05). With regard to piglet mortality, a linear mixed regression model showed a significant overall effect of treatment in reducing piglet mortality (P < 0.01). Yet, the effect of treatment varied according to litter size (number of liveborn piglets) with a diminishing treatment effect in sows with a high litter size (P < 0.01). Pre-weaning survival was improved in the current study by the combined effect of daily back scratching of sows prior to farrowing and providing music to sows and piglets during lactation. Further research is needed to assess the separate effects of both interventions.

Effects of various procedures for synchronisation of parturition in sows

Objective: The effects of various parturition controlling measures in sows on the relevant parameters for parturition were investigated. Material and methods: A total of 1975 study animals were divided into five groups: control group: A (n = 710); trial groups: B (n = 719), C (n = 180), D (n = 175), E (n = 191). The control group (A) included sows that spontaneously farrowed until day 114 of gestation. The remaining sows were administered a PGF2α-analogue (175 µg cloprostenol) on day 114. All sows that farrowed within 24 hours after prostaglandin-medication were summarised in trial group B. Dams that did not farrow until day 115 were either administered oxytocin (20 IU i. m., group C) or carbetocin in two different doses (70 µg, group D or 35 µg, group E). The sows were monitored during the peripartal period over 24 hours. Results: 83.8% of the farrowings were without any complications. The percentage of dystocia varied between the individual groups. Given a complication-free farrowing the expulsion stage began 13.0 hours (group B), 2.4 hours (group C), 1.6 hours (group D) and 1.4 hours (group E) after medication. The expulsion interval of the farrowing of two piglets decreased from 21.1 minutes with spontaneous farrowings (group A) to 18.6 minutes (group E) as a result of the administration of 35 µg carbetocin. The rate of stillborn piglets as well as the incidence of puerperal disorders and the losses of the suckling piglets also gradually, partly even significantly (p 0.05) decreased from group A to E. Conclusion and clinical relevance: The results of this study show that the use of the long-acting oxytocin carbetocin has advantages compared to oxytocin (e. g. shortened duration of birth, reduction of stillbirths). The tested dosages of carbetocin (35 µg or 70 µg) proved to be equally effective. Administration of the lower dose is recommended, since this reduces use of the active ingredient.

Impact of sow prepartum behavior on maternal behavior, piglet body weight gain, and mortality in farrowing pens and crates

In the 24-h period prior to parturition, sows are active and motivated to perform nest-building behavior. The aim of this study was to investigate whether prepartum activity (nesting and postural changes) could predict maternal behavior 24 h postpartum, piglet mortality, and BW gain 24 h postpartum in farrowing pens and crates. Sows were randomly moved either to a farrowing pen ( = 20) or a farrowing crate ( = 18). Prepartum nest-building behavior (PRE-nesting) and prepartum postural changes (prepartum postural changes) were analyzed 24 h before the birth of the first piglet (BFP) and were divided into twelve 2-h intervals. Latency of the first suckling from the litter was observed after the birth of the last piglet. Udder accesses and piglet suckling were noted at 5-min intervals, using 1/0 sampling, during the first 24 h after BFP were counted. Piglet trapping, crushing, and total live-born mortality were measured during the first 72 h after BFP. Piglet BW gain was estimated 24 h after BFP. Increased PRE-nesting observed 2 h before BFP were associated with fewer suckling intervals in crates but not in pens ( < 0.01) as well as an increase in postural changes during parturition ( < 0.001) in both housings. A link between housing and PRE-postural changes was evident. An increase in the number of PRE-postural changes 2 h prior to BFP was associated with lower incidences of udder access in crates but not in pens ( < 0.05). A higher probability of piglet trapping was associated with increased PRE-nesting in the 2 to 4 h before BFP. No significant relationship between either PRE-nesting and postural changes and piglet BW gain and mortality was detected. Our results suggest that increased prepartum activity 2 h before parturition is associated with less suckling and less udder access in farrowing crates but not in farrowing pens. This suggests that the same sow behavior can have different consequences in pens vs. in crates. Future research should focus on nest-building activity, its relationship to endocrine indicators (e.g., oxytocin, cortisol) before parturition, and its potential long-lasting effects on subsequent maternal behaviors and piglet production.

A Review of Pain Assessment in Pigs

There is a moral obligation to minimize pain in pigs used for human benefit. In livestock production, pigs experience pain caused by management procedures, e.g., castration and tail docking, injuries from fighting or poor housing conditions, “management diseases” like mastitis or streptococcal meningitis, and at parturition. Pigs used in biomedical research undergo procedures that are regarded as painful in humans, but do not receive similar levels of analgesia, and pet pigs also experience potentially painful conditions. In all contexts, accurate pain assessment is a prerequisite in (a) the estimation of the welfare consequences of noxious interventions and (b) the development of more effective pain mitigation strategies. This narrative review identifies the sources of pain in pigs, discusses the various assessment measures currently available, and proposes directions for future investigation.

High environmental temperature around farrowing induced heat stress in crated sows

The aim of the experiment was to study the impact of high ambient temperature (25°C) around farrowing on crated sows unable to perform thermoregulatory behavior. Twenty sows were housed in 2 farrowing rooms in conventional farrowing crates. In 1 room (CONTROL) temperature was kept at 20°C. In the other room (HEAT) temperature was initially kept at 20°C and gradually raised until it reached 25°C from d 112 to 115 of gestation. Then the temperature was gradually lowered to 20°C. Sows were continuously video recorded for behavior recording. Sows' respiration rates were recorded from d 3 before farrowing to d 5 after farrowing. Sows' rectal temperatures were recorded from d 1 before farrowing to d 8 after farrowing, and sows' udder surface temperatures were recorded from the day of farrowing to d 3 after farrowing. All measures were recorded daily. Sows' BW were recorded at d 108 of gestation and at weaning. Sows' back fat was recorded on farrowing day, when room temperature was set again at 20°C, and at weaning. Piglets were weighed at d 1, 14, and 21. The HEAT sows spent a higher proportion of time lying in the lateral position than CONTROL sows, both during the 16 h before farrowing and the 24 h after the start of farrowing ( < 0.05), but with no difference in the amount of time spent lying down between groups ( > 0.10). The HEAT sows had higher rectal temperature on d 1 after farrowing ( < 0.05) and had udder surface temperature 0.9°C higher than that of CONTROL sows during the recording period ( < 0.05). The HEAT sows also tended to have longer farrowing duration ( < 0.10). Respiration rate was higher in HEAT sows on d 1 before farrowing and on the day of farrowing. On d 7, 8, and 9, CONTROL sows had higher feed intake ( < 0.05), and piglets from CONTROL sows were heavier at d 21 after farrowing ( < 0.05). High ambient temperature around farrowing altered sows' postural behavior. Sows reacted to the thermal challenge with higher respiration rate around farrowing, but both their rectal and udder temperatures were elevated, indicating that they were not able to compensate for the higher ambient temperature. High ambient temperature negatively influenced sows' feed intake, with negative impact on piglets' weaning weight. High temperatures around farrowing (25°C) compromise crated sows' welfare, with a potential negative impact on offspring performance.

The identification of potential behavioural indicators of pain in periparturient sows

Periparturient pain is a welfare concern and could contribute to piglet losses. This has led to studies investigating post-farrowing analgesia. A clear reduction in pain has not been demonstrated, partly due to a lack of pain indicators. This study quantified behaviours as potential pain indicators (PPIn) in sows: i) before, during and after farrowing, and ii) 2min before and after piglet births. Twenty-five sows were observed during and after, and ten pre-farrowing. Behaviour recorded included: 1) back leg forward (back leg pulled forward and/or in); 2) tremble (movement as if shivering); 3) back arch (leg(s) stretch forming an arched back); 4) paw (leg scraped in pawing motion); and 5) tail flick (tail moved rapidly up and down). Behaviours were analysed using generalized linear models and Spearman's rank correlations. All PPIn were rare or absent pre-farrowing, highest during farrowing, and back leg forward, tremble and back arch were greater in the early post-farrowing period. Several significant positive correlations between PPIn during and post-farrowing were found. Back arch, tail flick and paw were higher before than after a piglet birth, and were more frequent earlier in the birth order. Back leg forward and tremble did not differ before and after births, and tremble increased with birth order. These behaviours, which were absent or rare pre-farrowing, present during farrowing and were lower afterwards, and showed consistent individual variation, may be quantitatively associated with pain. Spontaneous behaviours could be used to test the efficacy of analgesics or identify sows that may benefit.

The influence of sow behaviour on piglet mortality due to crushing in an open farrowing system

The objectives of this study were to establish what changes in posture by sows carried a high risk of piglet crushing in a group farrowing system during early lactation and also to determine what factors influenced the risk of crushing during lying down. A total of 24 Large White ✕ Landrace sows were studied during the first 7 days of lactation in a group farrowing system. Cross-fostering was not carried out so as not to influence behaviour. Dead piglets were removed and cause of death ascertained from external observation and post-mortem examination. Sow and piglet behaviour was video-recorded continuously. A total of 268 piglets were born alive, with 67 liveborn piglets subsequently dying during the 7-day experimental period, 50 as a result of crushing. A total of 7425 posture changes were analysed and 11 types of posture change were identified, the most dangerous being lying down from standing and those involving swapping sides, or rolling over, whilst lying.

Dangerous events during lying down were more likely to occur (1) in the first 24 h after farrowing, (2) when the sow lay down in the middle of the pen, (3) when the sow lay down without carrying out much piglet-directed pre-lying behaviour and (4) when the piglets were spread out but near to the sow. The amount of pre-lying behaviour decreased over time and crushing mortality also decreased. The results confirm that the piglets are most vulnerable to crushing during the first 24 h of life, when they are spending much of their time near the udder and have relatively poor mobility. Co-ordination of behaviour between the sow and her litter is important to reduce the risk of crushing. It is also important that the design of open farrowing systems incorporates knowledge about how crushing deaths occur in order to improve piglet welfare.

Genetic trends in maternal and neonatal behaviors and their association with perinatal survival in French Large White swine

Genetic trends in maternal abilities were studied in French Large White sows. Two lines representing old-type and modern-type pigs were obtained by inseminating modern sows with semen from boars born in 1977 or 1998. Successive generations were produced by inter-se mating. The maternal performance of sows from the second generation was compared in farrowing crates. Video analysis was performed for the 1st h after the onset of 43 and 36 farrowing events, and for the 6 first hours for 23 and 21 events, in old-type and modern-type sows, respectively. Genetic trends were estimated as twice the difference in estimates between the 2 lines. The contribution of behavior to the probability of stillbirth and piglet death in the first 2 days was estimated as the percentage of deviance reduction (DR) due to the addition of behavior traits as factors in the mortality model. Sow activity decreased strongly from the 1st to the 2nd h in both lines (P < 0.001). In the first 6 h, old-type sows sat (1st parity), stood (2nd parity) and rooted (both parities) for longer than modern-type sows, which were less active, especially in 2nd parity. In modern-type sows, stillbirth was associated positively with lying laterally in the first 6 h (4.6% DR) and negatively in the 1st h (9.1% DR). First-parity old-type sows were more attentive to piglets (P = 0.003) than modern-type sows which responded more to nose contacts at 2nd parity (P = 0.01). Maternal reactivity of modern-type sows was associated with a higher risk of piglet death (4.6% DR). Respiratory distress at birth tended to be higher in modern-type piglets than in old-type piglets (P < 0.10) and was associated with a higher risk of piglet death in both lines (2.7–3.1% DR). Mobility at birth was lower in modern-type than old-type piglets (P < 0.0001). Genetic trends show that sow and piglet behaviors at farrowing have changed. Our results indicate reduced welfare in parturient modern-type sows and their newborn piglets.

An association and haplotype analysis of porcine maternal infanticide: a model for human puerperal psychosis?

An association analysis using the Illumina porcine SNP60 beadchip was performed to identify SNPs significantly associated with porcine maternal infanticide. We previously hypothesised that this was a good animal model for human puerperal psychosis, an extreme form of postnatal mood disorder. Animals were selected from carefully phenotyped unrelated infanticide and control groups (representing extremes of the phenotypic spectrum), from four different lines. Permutation and sliding window analyses and an analysis to see which haplotypes were in linkage disequilibrium (LD) were compared to identify concordant regions. Across all analyses, intervals on SSCs 1, 3, 4, 10, and 13 were constant, contained genes associated with psychiatric or neurological disorders and were significant in multiple lines. The strongest (near GWS) consistent candidate region across all analyses and all breeds was the one located on SSC3 with one peak at 23.4 Mb, syntenic to a candidate region for bipolar disorder and another at 31.9 Mb, syntenic to a candidate region for human puerperal psychosis (16p13). From the haplotype/LD analysis, two regions reached genome wide significance (GWS): the first on SSC4 (KHDRBS3 to FAM135B), which was significant (-logP 5.57) in one Duroc based breed and is syntenic to a region in humans associated with cognition and neurotism; the second on SSC15, which was significant (-log10P 5.68) in two breeds and contained PAX3, which is expressed in the brain.

Dietary fibre for gestating sows: effects on parturition progress, behaviour, litter and sow performance

In pig production, parturition progress is a key event for sow's reproductive performance, evaluated by piglet survival and piglets' performance. The aim of this study was to investigate the impact of feeding a high-fibre (HF) diet during gestation on parturition progress and reproductive performance of sows. Forty-two primiparous sows (Large-White × Landrace crossbred) were fed during gestation either a control diet (C diet; 2.40 kg/day, 3.2% crude fibre, in % of dry matter (DM)), or a HF diet (2.80 kg/day, 12.4% crude fibre, in % of DM). All sows received 33 MJ digestible energy per day. Continuous video recordings were done on the parturition day to determine postural changes (standing, sitting, lying) and behavioural activities (nesting behaviour, uterine contractions, restlessness, social behaviour towards piglets) during parturition. Duration of parturition and individual birth intervals were also measured. Piglets' growth was evaluated by weekly weighing from birth until weaning, at 26.5 days of age. Sows were weighed and backfat thickness was measured at mating, on day 105 of gestation, on the 1st day post partum, and at weaning. Durations of parturition and of birth intervals were not affected by the gestation diet and averaged 211 ± 12 min and 16.5 ± 0.9 min (mean ± s.e.), respectively. During the parturition progress, the gestation diet did not affect the frequency and the time devoted to postural and behavioural activities. Dietary treatment during gestation did not influence duration of gestation and weaning-to-oestrus interval, as well as litter size, and number of stillborn and weaned piglets. Piglet weight at birth did not differ between gestation dietary treatments but piglets nursed by HF sows showed a 13.5% greater growth rate during the 1st week of life (P < 0.01) and tended to be heavier at weaning (P = 0.06) compared with C piglets. The HF sows were leaner at the end of gestation (P < 0.05), but variations of sows' weight during gestation and lactation were not affected by the gestation diet. All sows lost the same amount of backfat thickness during lactation. During lactation, the average daily feed intake was not significantly affected by the gestation diet. This study shows that substituting a control diet for a HF diet during gestation has limited effects on farrowing progress and reproductive performance, but improved piglets' growth rate during the 1st week of life and tended to increase their live weight at weaning.

Effects of meloxicam (Metacam®) on post-farrowing sow behaviour and piglet performance

Farrowing is an intrinsically risky process for both the sow and the piglets that can cause welfare and economic problems. The effects of the non-steroidal anti-inflammatory drug meloxicam on post-farrowing behaviour of sows, and the performance of piglets were investigated. A total of 48 sows were randomly allocated at the day of farrowing (day 0) into two homogeneous groups regarding parity, and treated with either meloxicam or saline solution as placebo. For each sow, number of position changes, total time lying and standing or sitting, feed intake and rectal temperature (RT) were recorded during 3 days after farrowing. Piglets were individually weighed at farrowing and at weaning. The number of position changes did not show significant differences between treatments (P = 0.79). Sows spent significantly less time lying during day +3 after farrowing in the meloxicam group than in the placebo group (P = 0.04). Feed intake and RT showed a parity effect (P < 0.001 in both cases); however, no treatment effect was observed (P = 0.67 and P = 0.47, respectively). Pre-weaning mortality rate in piglets was not affected by treatment. In litters from multiparous sows, piglets of low birth weight (defined as percentile 15: BW <1180 g) had an average daily gain significantly higher in the meloxicam group than in the placebo group (196.6 ± 7.2 v. 166.6 ± 9.1 g/day; P = 0.03). Although the administration of meloxicam 90 min after farrowing showed a positive effect on the total time lying of the sows, additional investigations are required to better qualify relevant indicators of pain following farrowing in sows and to specify the analgesic effects of meloxicam on piglet performance.

The effect of nesting material on the nest-building and maternal behavior of domestic sows and piglet production

Nest building is an important part of maternal behavior in domestic pigs. The aim of the study was to assess the effect of nesting material sawdust vs. straw on sow behavior 24 h before and after birth of the first piglet (BFP) and piglet production. Sows, housed in farrowing crates, were randomly divided into 2 treatments: sawdust (n = 12) and straw (n = 13). Sawdust and straw were provided during the pre- and parturient period; after parturition, straw was given to both experimental groups. The prepartum nesting period (the time interval between the first and last nest-building records, including all other activity and resting before BFP), the nesting records (number of nesting records), nesting duration (duration of all nesting records), the start and termination of nesting, and the frequency of prepartum postural changes were collected 24 h before BFP. After BFP, number of nesting records and time to first sucking of the litter were collected. Frequency of postural changes and duration of udder access were collected 24 h after BFP during 3 time periods (during parturition, from the end of parturition to 12 h after BFP, and 12 to 24 h after BFP) and the frequency of nursing during 2 time periods (from the end of parturition to 12 h after BFP, and 12 to 24 h after BFP). Piglet BW gain and mortality were estimated 24 h after BFP. Data were analyzed using PROC MIXED and the probability of the piglet mortality using PROC GENMOD in SAS. Nesting material did not affect (P > 0.10) most of sow prepartum nesting behavior and had no effect (P > 0.10) on the prepartum frequency of postural changes. Sows from the sawdust treatment had a longer nesting period (P < 0.05), and nest building tended to start sooner (P < 0.10) than in the straw treatment. Nesting material had only a small effect on later maternal behavior. Sows from the straw treatment tended to have more nesting records after BFP (P < 0.10). The frequency of postural changes was affected by the interaction (P < 0.01) between treatments and time period: sow from the straw treatment had more postural changes during parturition compared with other time periods and sawdust treatment. No effect (P > 0.10) of the nesting material on piglet BW gain and mortality was found. The results suggest that sawdust compared with straw as nesting material provided to sows before and through parturition does not negatively affect maternal behavior during the 24 h before and after parturition or piglet production. Therefore, sawdust can be recommended as a suitable nesting material for farrowing sows when straw is not available.

A behavioural scale to measure ease of farrowing in sows

Farrowing is one of the most critical phases in pig production, as it has an impact on neonatal pig survival. Assessing the ease of farrowing can improve the management of sows and thus increase litter survival. The aims of this study were: 1) to develop an ease of farrowing score (EFS) in sows based on the behaviour of the sows and their piglets, and 2) to determine the relationship between the EFS and productive, physiological, and subjective parameters. Eighty hybrid (Large White × Landrace) sows from first to seventh parity housed in individual crates were used. An EFS was constructed using the total duration of farrowing, the birth interval, the total time standing or sitting, the number of position changes during the day before and the day of farrowing, the sow posture at birth, the viability and the position of the piglets at birth (head or back born). Moreover, rectal temperature at 90 min after farrowing, a four categorical subjective visual assessment (VA) of farrowing and litter size (piglets born alive, stillborn and mummified foetus) were recorded. A common factor analysis model yielded five factors with an eigenvalue higher than 0.95 that accounted for 75.05% of the total variation between individuals. The three main factors were "farrowing duration", "sow posture", and "sow activity" of sows and explained 23.44%, 15.67%, and 14.23% of the variance, respectively. Primiparous sows had higher values for factor 3 (sow activity) than multiparous sows (P = 0.02). Sows without stillborn or mummification foetus showed higher values of EFS than sows with at least one stillborn or mummification foetus (P = 0.06 and 0.01, respectively). Sows that received a visual assessment of 3 and 4 showed higher values of EFS than sows that received a VA of 1 and 2 (P = 0.0017). The EFS appears to be a good behavioural scale to measure ease of farrowing in sows kept in individual farrowing crates. Duration of farrowing, sow position, and presence of stillborn piglets and mummified foetuses appear to be important ease of farrowing indicators.

Porcine maternal infanticide as a model for puerperal psychosis

Childbirth is a period of substantial rapid biological and psychological change and a wide range of psychotic disorders can occur ranging from mild 'baby blues' to severe episodes of psychotic illnesses. Puerperal psychosis is the most extreme form of postnatal psychosis, occurring in 1 in 1,000 births. In this study, we have used the pig as an animal model for human postnatal psychiatric illness. Our aim was to identify quantitative trait loci (QTL) associated with maternal (infanticide) sow aggression. This is defined by sows attacking and killing their own newborn offspring, within 24 hr of birth. An affected sib pair whole genome linkage analysis was carried out with 80 microsatellite markers covering the 18 porcine autosomes and the X chromosome, with the aim of identifying chromosomal regions responsible for this abnormal behavior. Analysis was carried out using the non-parametric linkage test of Whittemore and Halpern, as implemented in the Merlin software. The results identified 4 QTL mapping on Sus scrofa chromosomes 2 (SSC2), 10 (SSC10), and X (SSCX). The peak regions of these QTL are syntenic to HSA 5q14.3-15, 1q32, Xpter-Xp2.1, and Xq2.4-Xqter, respectively. Several potential candidate genes lie in these regions in addition to relevant abnormal behavioral QTL, found in humans and rodents.