The effect of environment on behavioural activity, ACTH, (β-endorphin and cortisol in pre-farrowing gilts

Effects of Nesting Material Provision and High-Dose Vitamin C Supplementation during the Peripartum Period on Prepartum Nest-Building Behavior, Farrowing Process, Oxidative Stress Status, Cortisol Levels, and Preovulatory Follicle Development in Hyperprolific Sows

Hyperprolific sows often experience increased oxidative stress during late gestation and lactation periods, which can adversely affect the farrowing process and overall lactation performance. This study examines the influence of providing a coconut coir mat (CCM; 1 × 1 m) as nesting material, supplementing high-dose vit-C (HVC; 20% vit-C, 10 g/kg feed) as an antioxidant, or both on maternal behavior, the farrowing process, oxidative status, cortisol levels, and preovulatory follicle developments in sows with large litters. In total, 35 sows (Landrace × Yorkshire; litter size 15.43 ± 0.27) were allocated to the following four treatment groups: control (n = 9, basal diet), vit-C (n = 8, basal diet + HVC), mat (n = 10, basal diet + CCM), and mat + vit-C (n = 8, basal diet + HVC + CCM). A post-hoc analysis showed that compared with sows that were not provided CCM, mat and mat + vit-C groups demonstrated increased durations of nest-building behavior during the period from 24 h to 12 h before parturition (p < 0.05 for both), reduced farrowing durations, and decreased intervals from birth to first udder contact (p < 0.01 for both). The mat group exhibited lower advanced oxidation protein product (AOPP) levels during late gestation and lactation periods than the control group (p < 0.05). Sows with HVC supplementation showed longer farrowing durations than those without HVC supplementation (p < 0.0001). The vit-C group had higher salivary cortisol levels on day 1 after farrowing than the other treatment groups (p < 0.05). Furthermore, the follicle diameters on day 3 after weaning in the vit-C group tended to be smaller than those in the control group (p = 0.077). HVC supplementation prolonged farrowing and increased the physiological stress on postpartum, and no advantageous effects on maternal behavior and developmental progression of preovulatory follicles were observed. Hence, alternative solutions beyond nutritional approaches are required to address increased oxidative stress in hyperprolific sows and secure their welfare and reproductive performance. The present results substantiated the positive impact of providing CCM as nesting material for sows with large litters on nest-building behavior and the farrowing process, which could mitigate the deleterious consequences induced by peripartum physiological and oxidative stress.

Investigating the effects of jute nesting material and enriched piglet mats on sow welfare and piglet survival

Domesticated sows are motivated to perform nesting behavior prior to farrowing, and nesting material can reduce piglet cold stress. However, nesting material may not be practical in most production systems due to the potential for clogging slurry systems. Therefore, the study objectives were to assess an alternative nesting material provided prior to farrowing on sow welfare and piglet survival, and to investigate the effect of the entire nesting environment on piglet survival and growth performance. We hypothesized that the provision of jute nesting material would decrease sow stress and farrowing duration, and that nesting mat provision would allow piglets to remain euthermic and improve survival and growth. Sows (N = 20) were randomly assigned to one of two treatments: a farrowing crate with three pieces of 40.6 × 21.6 cm jute nesting material (Nest; n = 10) and two enriched piglet mats made from an acrylic board (28.0 × 86.4 cm) covered with a microfiber material, or a farrowing crate without nesting material (Control; n = 10) and one standard plastic piglet mat (28.0 × 86.4 cm). Jute pieces were attached to the front of the crate to prevent substrate from falling through the slatted floors. Saliva samples were collected to measure cortisol and immunoglobulin A (IgA), on days -1, 0, 1, and 2 relative to farrowing, and a final sample was collected at weaning (day 16.9 ± 0.18). Blood was collected from four piglets per litter to measure immunoglobulin G (IgG) at 48 h, day 7, and weaning. Piglet skin temperature (TS) was measured on two piglets per litter using an infrared camera for 3 d after birth at 0800, 1200, 1600, and 2000 h. One piglet was randomly chosen from the heat lamp and nonheat lamp side of the crate to measure TS. Video was continuously coded for observations of jute- and crate-directed interactions. Data were analyzed as a mixed model analysis of variance in SAS 9.4. Nest sows performed less crate-directed behavior than Control sows (P = 0.02). Cortisol tended to be reduced in Nest sows (P = 0.08) when compared to Controls, but no differences in IgA concentrations (P > 0.40) were detected. Nest piglets tended to be heavier on day 7 (P < 0.10), had greater IgG concentrations (P = 0.03), and had greater TS (P = 0.02) versus Controls. No farrowing duration or number of stillbirth differences were observed (P > 0.70). The jute material and piglet nests positively impacted sow welfare and piglet measures but did not translate into improved piglet survival.

Welfare of pigs on farm

This scientific opinion focuses on the welfare of pigs on farm, and is based on literature and expert opinion. All pig categories were assessed: gilts and dry sows, farrowing and lactating sows, suckling piglets, weaners, rearing pigs and boars. The most relevant husbandry systems used in Europe are described. For each system, highly relevant welfare consequences were identified, as well as related animal-based measures (ABMs), and hazards leading to the welfare consequences. Moreover, measures to prevent or correct the hazards and/or mitigate the welfare consequences are recommended. Recommendations are also provided on quantitative or qualitative criteria to answer specific questions on the welfare of pigs related to tail biting and related to the European Citizen's Initiative 'End the Cage Age'. For example, the AHAW Panel recommends how to mitigate group stress when dry sows and gilts are grouped immediately after weaning or in early pregnancy. Results of a comparative qualitative assessment suggested that long-stemmed or long-cut straw, hay or haylage is the most suitable material for nest-building. A period of time will be needed for staff and animals to adapt to housing lactating sows and their piglets in farrowing pens (as opposed to crates) before achieving stable welfare outcomes. The panel recommends a minimum available space to the lactating sow to ensure piglet welfare (measured by live-born piglet mortality). Among the main risk factors for tail biting are space allowance, types of flooring, air quality, health status and diet composition, while weaning age was not associated directly with tail biting in later life. The relationship between the availability of space and growth rate, lying behaviour and tail biting in rearing pigs is quantified and presented. Finally, the panel suggests a set of ABMs to use at slaughter for monitoring on-farm welfare of cull sows and rearing pigs.

Review of Temporary Crating of Farrowing and Lactating Sows

Temporary crating (TC) provides lactating sows with the opportunity to move more freely after crate opening a few days after parturition. The aim of this paper was to evaluate whether TC gives overall welfare improvement when compared to permanent crating or free farrowing. This review shows that when pens with TC allow the sows to turn during the majority of time in the farrowing unit, it is the pen design and period of confinement in a crate within it that influence the extent to which different functional and motivated behaviors can be fulfilled. This review also indicates that there are at least short-term benefits to sows when confinement is reduced, as shown by reported increases in motivated behaviors such as exploration and interactions with piglets when not permanently crated. It remains unclear whether there are any longer-term beneficial effects (until or beyond weaning) due to the paucity of studies. Furthermore, it is uncertain whether the observed short-term benefits translate to other welfare indicators. Research findings indicate no reduction in the frequency of stereotypies or body lesions and do not provide a clear answer regarding sow stress response when released from confinement. Compared to free farrowing, TC appears beneficial for reducing piglet mortality. The impact of the time of onset of TC on the farrowing process and piglet mortality have been inconsistent. While confinement before farrowing prevents nest building behavior, consequences of this for sow physiology have been ambiguous. Confining the sow briefly after farrowing may be the best compromise, allowing the sow to perform motivated nest-building behavior, but the risks of crushing during the unconfined farrowing period may increase. Subsequent crate reopening seems to increase piglet mortality but only if done earlier than 3–5 days after farrowing. The review also provides methodological considerations, a proposal for consistent and accurate terminology when describing systems and highlights gaps of knowledge. In conclusion, TC is a step forward to better pig welfare compared to the farrowing crate, as it allows some freedom of movement for sows without impairing piglet welfare. However, more comprehensive research is needed to draw sound conclusions as to whether TC is a viable transition from permanent crating to free farrowing.

Short confinement of sows after farrowing, but not pen type affects live-born piglet mortality

Over the last decades, permanent crating of farrowing and lactating sows has led to serious public concerns with regard to sow welfare. As one alternative, it has been suggested to restrict crating to the period when suckling piglets are at the highest risk to die. Therefore, the aim of this study was to investigate live-born piglet mortality with regard to different confinement periods (CFP) as well as farrowing pen types. On three research farms (A, B and C), four confinement periods were compared: In CFP 0 (control), sows were not confined at all, sows in CFP 3 were crated after the end of farrowing for three days. In CFP 4, sows were confined one day before the due date of farrowing until three days after parturition and sows in CFP 6 were crated one day before expected farrowing until five days after parturition. Furthermore, five different pen types designed for temporary crating (PT; 5.5-7.3 m²) were compared. In total, production data from 638 litters were analysed. For each piglet found dead (n = 1 580), the cause of death was determined by the farm personnel and verified by necropsy (all three farms) and additional video analysis (farms A and B only). Data were analysed using logistic mixed models with CFP 0 and pen type Fluegel as reference categories (CFP 0 was control and this pen type was present on all three farms and the largest number of litters was born in this pen type). Live-born piglet mortality was lower in temporarily crated sows than in sows without confinement (CFP 0; P < 0.015). Pairwise posthoc tests did not reveal differences between CFP 3, CFP 4 and CFP 6 (odds ratios 0.75, 0.59 and 0.69), nor between pen types. Additional factors associated with increasing live-born piglet mortality were larger litter size, higher sow parity as well as the administration of hormones around farrowing. Factors influencing mortality due to crushing were similar to those for total live-born mortality with the exception of CFP 3 not differing significantly from CFP 0. It can be concluded, that confinement of the sow for three days after farrowing is an effective measure to reduce live-born piglet mortality in the pen types tested. An extension of the confinement period to five days after parturition does not result in a further reduction of live-born mortality rate.

Parental Behaviour in Sows

Parental behaviour in sows begins with prepartum nest-building behaviour, which mainly consists of rooting, pawing, and foraging, to achieve a structure for farrowing and to nurse and protect the offspring. A hormonal background is linked to the onset and cessation of nest-building behaviour. The ambient farrowing environment that can adequately address the needs for nest-building behaviour thus plays an important role in good parental behaviour of the sows during and after farrowing. In addition to these environmental factors, here we also discuss other well-known intrinsic factors, such as heredity, parental experience, and litter size, affecting parental behaviour of the sows for successful farrowing and lactating performance.

Pre-farrow enrichment with burlap sheet: potential benefit for sow performance

Burlap has been proposed as an enrichment option for the conventional farrowing crate environment. Our objectives were to determine if burlap sheets hung in farrowing crates were used by sows and piglets and had any effect on farrowing and litter performance. Before sow entry, a sterilized burlap sheet (165 cm × 60 cm) was attached to every second farrowing crate so that it hung to the floor with easy animal access. Its length was measured immediately after farrowing and weaning. Routine sow and litter information from farrowing to weaning (day 18) were recorded. Complete data were analyzed for mixed-parity sows and litters with burlap (BURL; n = 277) and without burlap (CTRL; n = 277). Sows and their litters manipulated the burlap sheet to varying degrees. The BURL sows had a lower percentage of stillbirths (6.5% vs. 8.3%, BURL vs. CTRL, SE 0.4; P = 0.004), although there was only a trend towards more born alive (13.00 vs. 12.54, SE 0.25; P = 0.113). More piglets were fostered off BURL sows (8.4 vs. 7.1, SE 0.5; P = 0.049). No significant differences were apparent for other sow and litter measurements. Burlap sheets as a farrowing crate enrichment have potential to improve sow and litter performance.

The effect of hessian and straw as nesting materials on sow behaviour and piglet survival and growth to weaning

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.

Are Larger Litters a Concern for Piglet Survival or an Effectively Manageable Trait?

As sows continue to be selected for greater prolificacy, it is important to review problems that arise in larger litters, and whether these issues can be appropriately managed. Although a proportion of piglets in larger litters can be born underweight, proper supervision around farrowing and adequate colostrum intake has the potential to improve the survival of low-birth-weight piglets and their ongoing growth to weaning. As larger litters can impart greater stress and discomfort on sows, implementing a low-stress environment leading up to parturition may improve sow performance and subsequent survival of piglets. Additionally, treating sows with anti-inflammatory compounds, either dietary or pharmacologically, shows some promise for alleviating sow discomfort and improving piglet survival in larger litters. Understanding that selecting sows for larger litters not only affects piglet survival but the well-being of the sow, the decision to continue selecting for larger litters, regardless of management strategies, remains a topic of ethical concern.

Prioritization of Farm Animal Welfare Issues Using Expert Consensus

Prioritization of animal welfare issues can help identify which areas most require research funding and raise awareness of best practices. A modified Delphi method was used to obtain expert opinion on the highest priority welfare issues for UK farmed livestock. Fifty-eight UK-based experts were recruited onto the study, with a minimum of 3 years experience of working with either cattle, pigs, poultry, or small ruminants (12-16 experts per group). Experts were chosen to represent a broad range of opinions. Two rounds of surveys were conducted online using Online Survey, and the final round was an in-person workshop with 21 experts. In the first survey, experts were provided with a comprehensive list of species-specific welfare issues derived from the literature. Participants were asked to score each welfare issue, for (i) severity, (ii) duration, and (iii) prevalence on a 6-point Likert scale. The results of the first survey were reviewed and the welfare issues which scored a neutral-to-high response (scores 3-6) were carried forward. In round 2, participants were asked whether they agreed or disagreed with the rankings that were made from the results of round 1. The final stage of the process was a workshop, which consisted of a combination of group exercises and discussions, to reach the final consensus. Welfare priority lists were divided into two categories: severity/duration, and prevalence, to identify the priority welfare issues affecting individual animals and the population, respectively. Across all farmed species common concerns were inadequate or inappropriate nutrition, inability of stockpeople to recognize or treat welfare issues (such as pain or behavioral problems), lameness, chronic or endemic health issues, euthanasia and mortality and morbidity of neonates. Specific concerns related to behavioral restriction and damaging or abnormal behavior in pigs, poultry and dairy animals, inadequate housing for pigs and poultry, consequences of breeding decisions in pigs and poultry, and lack of access to veterinary care in sheep and beef. This Delphi process resulted in consensus on the most significant welfare challenges faced by UK livestock species and can help to guide future research and education priority decisions.

Periparturient Behavior and Physiology: Further Insight Into the Farrowing Process for Primiparous and Multiparous Sows

Giving birth is a critical time for many species and is often the most painful event ever experienced by females. In domestic species, like the pig, pain associated with parturition represents a potential welfare concern, and the consequences of pain can cause economic losses (e.g., by indirectly contributing to piglet mortality as pain could slow post-farrowing recovery, reduce food and water intake, reducing milk let-down). This study investigated pain assessment and its management in primiparous (gilts) and multiparous (sows) breeding pigs, including the provision of a non-steroidal anti-inflammatory drug (NSAID) post-parturition. Individuals were randomly allocated to receive the NSAID ketoprofen (3 mg/kg bodyweight) (n = 11 gilts, 16 sows) or the equivalent volume of saline (n = 13 gilts, 16 sows) by intramuscular injection 1.5 h after the birth of the last piglet. Data collected included putative behavioral indicators of pain (back leg forward, tremble, back arch), salivary cortisol concentrations pre-farrowing and up to 7 days post-injection. In addition, post-partum biomarkers of inflammation, including the acute phase protein C-reactive protein (CRP) and 3 porcine cytokines [interleukin-1 β (IL1 β), interleukin-6 (IL6), and tumor necrosis factor α (TNF α)] were measured in plasma collected 6 h following the injection. Behaviors were analyzed using generalized linear mixed models, and physiological variables with linear mixed models. No difference in putative pain behaviors, salivary cortisol, CRP, or cytokines were found between individuals treated with ketoprofen or those administered the saline control. However, there were some differences between gilts and sows, as sows exhibited more putative pain behavior than gilts, had higher salivary cortisol on the day of farrowing and had higher plasma TNF α. Conversely, gilts had higher salivary cortisol than sows on day 3 post-farrowing and had higher CRP. This indicates that, like human females, multiparous sows experience more pain from uterine activity following birth than primiparas. This study provides useful information for developing management practices relating to post-farrowing care for breeding pigs.

Temporary crate opening procedure affects immediate post-opening piglet mortality and sow behaviour

Producers are interested in utilising farrowing systems with reduced confinement to improve sow welfare. However, concerns of increased mortality may limit commercial uptake. Temporary confinement systems utilise a standard crate which is opened 3 to 7 days postpartum, providing protection for neonatal piglets at their most vulnerable age and later increased freedom of movement for sows. However, there is anecdotal evidence that piglet mortality increases immediately after the temporary crate is opened. The current study aims were to determine if piglet mortality increases post-opening, to trial different opening techniques to reduce post-opening piglet mortality and to identify how the different opening techniques influence sow behaviour. Three opening treatments were implemented across 416 sows: two involved opening crates individually within each farrowing house when each litter reached 7 days of age, in either the morning or afternoon (AM or PM), with a control of the standard method used on the farm to open all crates in each farrowing house simultaneously once the average litter age reached 7 days (ALL). Behavioural observations were performed on five sows from each treatment during the 6 h after crate opening, and during the same 6 h period on the previous and subsequent days. Across all treatments, piglet mortality was significantly higher in the post-opening than pre-opening period (P&lt;0.0005). Between opening treatments, there were significant differences in piglet mortality during the 2 days after crate opening (P&lt;0.05), whilst piglet mortality also tended to differ from crate opening until weaning (P=0.052), being highest in ALL and lowest in PM. Only sows in the PM treatment showed no increase in standing behaviour but did show an increased number of potentially dangerous posture changes after crate opening (P=0.01), which may be partly attributed to the temporal difference in observation periods. Sow behaviour only differed between AM and ALL on the day before crate opening, suggesting the AM treatment disrupted behaviour pre-opening. Sows in AM and PM treatments showed more sitting behaviour than ALL, and therefore may have been more alert. In conclusion, increases in piglet mortality after crate opening can be reduced by opening crates individually, more so in the afternoon. Sow habituation to disturbance before crate opening may have reduced post-opening piglet mortality, perhaps by reducing the difference in pre- and post-opening sow behaviour patterns.

Consistency is key: interactions of current and previous farrowing system on litter size and piglet mortality

Global interest in alternative indoor farrowing systems is increasing, leading to a growing number of farms utilising such systems alongside standard crates. There is evidence that interchanging sows between different farrowing systems affects maternal behaviour, whilst the subsequent effect of this on piglet mortality is unknown. The current study hypothesised that second parity piglet mortality would be higher if a sow farrowed in a different farrowing system to that of her first parity. Retrospective farm performance records were used from 753 sows during their first and second parities. Sows farrowed in either standard crates (crates), temporary crates (360s) or straw-bedded pens (pens), with mortality recorded as occurring either pre- or post-processing. Inter- and intra-parity sow consistency in performance were also investigated. Overall, total piglet mortality reduced from the first to the second parity, being significantly higher in the crates and higher in the 360s during the first or second parity, respectively. In the second parity, an interaction of the current and previous farrowing systems resulted in the lowest incidence of crushing for sows housed in the same system as their first parity for the crates and pens, but not the 360s. Post-processing mortality was significantly higher in the crates if a sow previously farrowed in the 360s and vice versa. Sows which previously farrowed in a pen had a significantly larger litter size and lower pre-processing mortality from crushing in their second parity than sows previously housed in the crates or the 360s. No inter-parity consistency of sow performance was found, whilst intra-parity consistency was found in the first but not second parity. In conclusion, returning sows to the same farrowing system appears to reduce piglet mortality, whilst farrowing in a pen during the first parity significantly increased second parity litter size without increasing piglet mortality.

Parturition effects on reproductive health in the gilt and sow

In this review, we address significant characteristics of parturition in the pig and their connection to post-partum reproductive health and fertility. We discuss the normal physiology and behaviour around parturition and the effect of the second phase (expulsion of foetuses) on the third phase of parturition (expulsion of foetal membranes). In addition, we intend to cover retained placenta, and the connection to post-partum uterine health and fertility in the contemporary prolific sow. We also explore factors that support successful parturition or can cause potential problems. Successful parturition in the pig includes the possibility to express adequate maternal behaviour, rapid expulsion of the piglets, complete expulsion of the placenta, neonatal activity and colostrum intake. Abnormal incidents during any phase of parturition can cause subsequent problems. Duration of the expulsion phase of foetuses can be used as a simple measure of whether parturition is considered successful. Prolonged parturition can impair health of the sow and piglet and fertility after weaning. New insights, such as adding more fibre to sow diets during pregnancy, and especially during the period prior to farrowing, may prevent constipation, increase water intake of the sow around parturition and increase milk intake and performance of piglets. Maternal characteristics, including maternal behaviour, ease of parturition, colostrum production and piglet quality parameters, may be utilized to improve success rate of reproductive management during farrowing and early lactation. Additionally, we share some of the recent developments in methods, including ultrasonography in evaluation of post-partum uterine health. In conclusion, successful farrowing is of the greatest importance for reproductive health of the sow and survival of the piglets. We suggest connections exist among prolonged farrowing and yield of colostrum, retained placenta, development of PDS, and impaired involution of the uterus and reduced subsequent fertility.

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.

Benefits of Prepartum Nest-building Behaviour on Parturition and Lactation in Sows - A Review

It is well known that prepartum sows have an innate motivation to build a nest before parturition. Under commercial conditions, however, the farrowing crate, which is widely used in modern pig husbandry, inhibits this innate behaviour through the lack of space, materials, or both. Thus, restriction of nest-building behaviour could generate increased stress, resulting in a decrease in maternal endogenous hormones. Hence, it could lead to detrimental effects on farrowing and lactating performance. Here we review interactions between prepartum nest-building behaviour, stress and maternal endogenous hormone levels, and discuss their effects on parturition, lactation, and welfare of sows and offspring.

Do umbilical outpouchings affect the behaviour or clinical condition of pigs during 6 h housing in a pre-transport pick-up facility?

This study focused on behavioural and clinical effects of umbilical outpouchings (UOs) in pigs. Matched pairs of pigs with UOs (diameter 12 cm; range 4-20; diagnosed p.m. as hernia or non-hernia) and controls (N=28) were compared during a 6-h stay in a pick-up facility. Overall, skin lesion scores were increased after the 6-h stay. Behaviour of the UO-pigs differed from the controls (a shorter latency to lie down (P<0.05) and decreased aggression (P<0.05)). Pigs with umbilical hernia showed e.g. increased sitting (P<0.05) and decreased lying (P<0.05) compared to pigs with non-hernia UOs. No effects of the size of the OUs were found. These results are among the first to establish knowledge about UO-pigs and suggest that a stay in a pick-up facility can be challenging for pig welfare. The behavioural findings suggest that UO-pigs, and especially pigs with hernia, may be less fit for mixing and housing in barren environments.

Confinement of sows for different periods during lactation: effects on behaviour and lesions of sows and performance of piglets

Alternatives to farrowing crates with continuous confinement of the sow are urgently needed because the animal welfare is negatively impacted. Given the increase of herd sizes, practical experience with loose-housing is needed to force the implementation of these systems in the field. Next to aspects of labour efficiency, detrimental piglet mortality rates that may occur during the first days postpartum (pp) is a major criticism. Therefore, loose-housing after a crating period limited to the first days pp might be a feasible alternative to improve welfare under intensive production conditions. The aim was to investigate the effect of crating sows during lactation for different periods on their behaviour and integument alterations and on piglets' performance. Gilts from a commercial herd were observed from 5 to 26 days pp and housed in farrowing crates (1.85×2.50 m) that could be altered between confinement crates and loose-housing pens. Animals were divided into three groups, that were either crated continuously from birth until weaning (Group A, n=55), until 14 days pp (Group B; n=54) or 7 days pp (Group C, n=59). The behaviour of six randomly selected gilts per group was video recorded from 5 to 26 days pp and analysed by time sampling technique. Lesions on the legs, shoulder and lumbar vertebra were scored on days 7, 14 and 25 pp. Piglets were weighed weekly, causes of losses recorded and weight losses of gilts measured. Not different between groups (P>0.05), animals spent 72 to 76% lying laterally, 14 to 17% lying in abdominal or semi-abdominal position, 9 to 10% standing and 1 to 3% sitting. B-sows were lying longer in week 3 and 4 of lactation compared to A- and C-sows (P0.05), whereas almost 90% of the losses occurred in the first week pp. In conclusion, loose-housing of lactating gilts after a reduced postnatal crating period of 7 days affected neither the activity level of the gilts and lesions on the integument nor pre-weaning mortality. Therefore, it is recommended to allow sows to move around to some extent during the later lactation period.

Post-mortem findings and piglet mortality in relation to strategic use of straw at farrowing

Piglet survival is the outcome of complex interactions between the sow, the piglet and their environment. In order to facilitate nest-building and to provide a suitable environment for the newborn piglets, a strategic method to supply loose housed sows with large quantities of straw at farrowing has been developed by Swedish piglet-producing farmers. The objectives of this cohort study were to use post-mortem findings to assess the causes of death and to quantify the effect of a large quantity of straw provided before farrowing compared to limited small daily amounts on stillbirths, post-mortem findings in piglets dying within 5 days after birth and the pre-weaning mortality. On each of four commercial piglet-producing farms in South-West Sweden, one batch of sows was studied during two consecutive lactations. At inclusion, sows were randomly assigned to two treatment groups, and sows remaining in the batch during the next lactation switched treatment group. In the STRAW group (n=181 litters) sows were provided with 15-20 kg of chopped straw 2 days prior to the calculated date of farrowing. Sows in the CONTROL group (n=182 litters) received 0.5-1 kg of chopped straw on a daily basis plus about 2 kg for nest-building when the stockperson judged the sow to be about to farrow. After onset of farrowing, additionally 1-2 kg was given. Post-mortem examination was performed in all piglets that died within 5 days after birth (n=798). The three major post-mortem findings were starvation (34%) crushing by the sow (28%), and enteritis (24%). In conclusion, strategic use of large quantities of straw reduced the number of stillborn piglets per litter by 27% (p=0.007). Under the conditions studied, the pre-weaning mortality of liveborn piglets was not affected by treatment; however, the distribution of post-mortem findings differed with fewer piglets dying due to starvation and more due to crushing and enteritis in STRAW litters.

Confinement of lactating sows in crates for 4 days after farrowing reduces piglet mortality

To reduce mortality among suckling piglets, lactating sows are traditionally housed in farrowing crates. Alternatively, lactating sows can be housed in farrowing pens where the sow is loose to ensure more behavioural freedom and consequently a better welfare for the sow, although under commercial conditions, farrowing pens have been associated with increased piglet mortality. Most suckling piglets that die do so within the first week of life, so potentially lactating sows do not have to be restrained during the entire lactation period. Therefore, the aim of the current study was to investigate whether confinement of the sow for a limited number of days after farrowing would affect piglet mortality. A total of 210 sows (Danish Landrace × Danish Yorkshire) were farrowed in specially designed swing-aside combination farrowing pens measuring 2.6 m × 1.8 m (combi-pen), where the sows could be kept loose or in a crate. The sows were either: (a) loose during the entire experimental period, (b) crated from days 0 to 4 postpartum, (c) crated from days 0 to 7 postpartum or (d) crated from introduction to the farrowing pen to day 7 postpartum. The sows and their subsequent litters were studied from introduction to the combi-pen ∼1 week before expected farrowing and until 10 days postpartum. Confinement period of the sow failed to affect the number of stillborn piglets; however, sows that were crated after farrowing had fewer live-born mortality deaths (P < 0.001) compared with the sows that were loose during the experimental period. The increased piglet mortality among the loose sows was because of higher mortality in the first 4 days after farrowing. In conclusion, the current study demonstrated that crating the sow for 4 days postpartum was sufficient to reduce piglet mortality.

Animal welfare and economic optimisation of farrowing systems

In many countries, including the UK, the majority of domestic sows are housed in farrowing crates during the farrowing and lactation periods. Such systems raise welfare problems due to the close confinement of the sow. Despite the fact that many alternative housing systems have been developed, no commercially viable/feasible option has emerged for large scale units. Current scientific and practical knowledge of farrowing systems were reviewed in this study to identify alternative systems, their welfare and production potential. The aim was to establish acceptable trade-offs between profit and welfare within alternative farrowing systems. Linear programming (LP) was used to examine possible trade-offs and to support the design of welfare-friendly yet commercially viable alternatives. The objective of the LP was to optimise the economic performance of conventional crates, simple pens and designed pens subject to both managerial and animal welfare constraints. Quantitative values for constraints were derived from the literature. The potential effects of each welfare component on productivity were assessed by a group of animal welfare scientists and used in the model. The modelled welfare components (inputs) were extra space, substrate and temperature. Results showed that, when using piglet survival rate in the LP based on data drawn from the literature and incorporating costs of extra inputs in the model, the crates obtained the highest annual net margin and the designed pens and the pens were in second and third place, respectively. The designed pens and the pens were able to improve their annual net margin once alternative reference points, following expert-derived production functions, were used to adjust piglet survival rates in response to extra space, extra substrate and modified pen heating. The non-crate systems then provided higher welfare and higher net margin for sows and piglets than crates, implying the possibility of a win-win situation.

Neonatal piglet traits of importance for survival in crates and indoor pens

The primary aim of the present study was to investigate whether the same piglet traits contributed to the same causes of neonatal piglet mortality in crates (CT) and pens (PN). Gilts originating from 2 distinct genetic groups that differed in breeding value for piglet survival rate at d 5 (SR5) were used. These were distributed to farrow in either PN or CT as follows: high-SR5 and CT (n = 30); low-SR5 and CT (n = 27); high-SR5 and PN (n = 22); and low-SR5 and PN (n = 24). Data on individual piglets were collected at birth, including interbirth interval; birth order; birth weight; rectal temperature at birth, 2 h after birth, and 24 h after birth; cordal plasma lactate; and latency to first suckle. Based on autopsy, causes of mortality were divided into stillborn, bitten to death, starvation, crushed, disease, and other causes. Potential risk factors of dying were estimated using a GLM with a logit link function. No significant effect (NS) of housing was observed on the odds of a piglet being stillborn (F(1,73) = 0.1, NS), being crushed (F(1,53) = 1.4, NS), or dying of starvation (F(1,53) = 0.3, NS). No significant differences were observed between the 2 genetic groups for any category of mortality. Piglet traits for pre- and postnatal survival were the same for CT and PN. The odds of being stillborn were increased in piglets born late in the birth order (F(1,1061) = 33.5, P < 0.0001), after a long interbirth interval (F(1,1061) = 19.2, P < 0.0001), and with a lighter birth weight (F(1,1061) = 9.2, P = 0.003). The lighter the birth weight of the piglets, the greater were the odds of being crushed (F(1,1050) = 18, P < 0.0001) and dying of starvation (F(1,1050) = 19, P < 0.0001). The lower the rectal temperature 2 h after birth, the greater were the odds of being crushed (F(1,1050) = 4.6, P = 0.03), starving (F(1,1050) = 16.6, P < 0.0001), or dying of diseases (F(1,1050) = 4.9, P = 0.03). Increased cordal plasma lactate increased the odds of dying from starvation (F(1,1050) = 18, P < 0.0001). In both CT and PN, the birth weight, body temperature 2 h after birth, and birth process were important traits related to crushing, starvation, and disease. Neither housing nor breeding value influenced mortality or traits of importance for the inborn viability of piglets. The results emphasize that the microclimate in the PN for newborn piglets and its heat-preserving properties are more important for survival than whether the sow is crated or penned.

Investigating the behavioural and physiological indicators of neonatal survival in pigs

Survival is reduced in low birth weight piglets, which display poor thermoregulatory abilities and are slow to acquire colostrum. Our aim was to identify additional behavioural and physiological indicators of piglet survival incorporating traits reflective of both the intrauterine and extrauterine environment. Data were collected from 135 piglets from 10 Large White x Landrace sows to investigate which physiological measurements (e.g. individual placental traits), and which behavioural measurements (e.g. the quantification of piglet vigour), were the best indicators of piglet survival. Generalised linear models confirmed piglet birth weight as a critical survival factor. However, with respect to stillborn mortality, piglet shape and size, as measured by ponderal index (birth weight/(crown-rump length)(3)), body mass index (birth weight/(crown-rump length)(2)), respectively, and farrowing birth order were better indicators. With respect to live-born mortality, postnatal survival factors identified as crucial were birth weight, vigour independent of birth weight, and the latency to first suckle. These results highlight the importance of the intrauterine environment for postnatal physiological and behavioural adaptation and identify additional factors influencing piglet neonatal survival.

Loose farrowing systems: challenges and solutions

The use of farrowing crates is increasingly questioned from an animal welfare point of view. Even so, since a number of attempts to develop loose farrowing systems have been unsuccessful, leading to high levels of piglet mortality due in the main to crushing, many farmers remain sceptical as to whether or not alternative systems can be viable. On the other hand, several European countries have introduced legislation requiring loose farrowing systems, thus promoting research into this type of housing and allowing for performance studies based on large samples of commercial farms. As a consequence of these recent developments, we think it timely to reconsider the evidence available on loose farrowing systems. In our review, we first address the normal peri-parturient behaviour of domestic pigs, as well as studies comparing behaviour and stress physiology in sows kept in both crates and loose systems during farrowing. We then review approaches taken to develop alternative farrowing systems in different countries, and focus lastly on pen, piglet and sow characteristics that contribute to piglet survival in loose farrowing systems. Taking scientific evidence as well as practical experience into account, we conclude that piglet mortality in loose farrowing systems need not exceed that of crate systems. To obtain good performance results, sows due to farrow should be kept individually in sufficiently large pens, structured for preference into a nest area and an activity area. Furthermore, both management and breeding aspects, resulting in high piglet viability and good maternal behaviour, are essential to achieve high production in loose farrowing systems.

Stress, behaviour and reproductive performance in female cattle and pigs

Female farm animals are exposed to a great variety of environmental and management related stressors. As a consequence, their reproductive and maternal abilities may be compromised through mechanisms acting on the hypothalamic, pituitary, ovarian and uterine function. Responses to short- and long-term stressors may differ as short-term stressors often fail to affect reproduction or even may have stimulatory effects. Thus, the stress response induces diverse neuroendocrine reactions that can either increase or decrease the probability of an animal reproducing depending on the specific situation. The aim of the present review is to summarise the current knowledge on the stress concept and its implications on behaviour and reproductive performance in cows and female pigs as phenomena reported in laboratory animals are unable to explain all effects encountered in domesticated farm animals.

Programming the offspring of the pig by prenatal social stress: neuroendocrine activity and behaviour

This study provides evidence in the pig that stress experienced during gestation has long-lasting effects on offspring daughters, including their maternal behaviour. Thirty-six primiparous sows were divided into control and two groups that were stressed (by social mixing) during either the second (Mix 2) or third (Mix 3) trimester of pregnancy. We found detrimental effects of mixing on the mothers' growth, body lesions, and cortisol secretion, but did not observe any significant effects on reproductive parameters including birth weight. At 60 days of age, 48 daughters were randomly selected from the three treatments: half were challenged using a restraint and isolation test. Then, all were culled and brain tissue was collected. In situ hybridisation measurements showed increased expression of CRH mRNA in the PVN in unrestrained Mix 2 and in the amygdala of Mix 2 and Mix 3 daughters. At 67 days, 24 further daughters were mixed to measure their responses to this social stress. All showed increased salivary cortisol secretion, but Mix 2 and Mix 3 daughters showed a greater and longer response than controls. Finally, all 24 were inseminated and at parturition maternal behaviour was measured. Mix 2 and Mix 3 daughters were more restless and more responsive to piglets that approached the head of the sow, traits which previously have been shown to be a component of abnormal maternal behaviour. Indeed, Mix 2 and Mix 3 daughters also tended to bite at their piglets more than control daughters.

Consistency of piglet crushing by sows

Piglet mortality is a major welfare and economic problem in the pig industry. Despite the use of farrowing crates, piglet crushing remains a major contributor to pre-weaning piglet mortality, which is typically around 12%. Our aims in this study were to quantify variability between sows and consistency across parities in crushing mortality, and to examine the effect of the environment on variability. In our first study, we compared the variability in crushing mortality in 122 primiparous sows (gilts) that farrowed in crates (71) or open pens (51). Certain sows crushed more or fewer piglets than expected by chance. Crushing was more frequent and more variable in pens compared to crates, indicating that crates may mask differences between sows. In our second study, we recorded piglet mortality for 125 sows, which farrowed in crates over several (4–9) parities. After adjusting for litter size, litter weight and parity effects, consistent individual differences between sows were evident. The repeatability of crushing was estimated at 0.14, with estimates of 0.18 and 0.05 for stillborns and total liveborn mortality, respectively. Although these repeatabilities are relatively low, there was a high degree of phenotypic variance (eg sows crushed between 0 and 30.8% of their piglets). Given that sows show some consistency in piglet mortality over parities, this could be used to inform culling decisions. Additionally, if differences in piglet crushing between sows have a genetic component, a breeding programme might reduce mortality from crushing. Because crates restrict maternal behaviour, genetic selection in this system may have relaxed selection for good maternal behaviour. Selection for reduced piglet mortality, and thus improved maternal abilities, could remove a major obstacle to the wider adoption of less restrictive farrowing systems, with positive welfare consequences for the sow and piglets.