M. J. Harris

A cohort study of preweaning piglet mortality and farrowing accommodation on 112 commercial pig farms in England

A cohort study was carried out on 112 breeding pig farms in England to investigate the impact of type of farrowing accommodation on preweaning mortality in piglets. Four types of farrowing accommodation were studied; farrowing crates, indoor loose pens, crate/loose systems (where the sow was restrained in a crate during birth and the first days of lactation before being moved to a loose pen) and outdoor farrowing in arcs in paddocks. Four estimates of preweaning mortality were collected: an oral estimate from the farmer before the visit, an estimate from the 6-month rolling average from computer records, records from 20 litters observed when the farm was visited and prospective records collected from 20 farrowings after the visit. These four estimates were significantly correlated. The prospective records also included a farmer reported date and cause of death. From the prospective data there were 25,031 piglets from 2143 litters from 112 farms, 6.5% of piglets were stillborn while live born preweaning mortality was 12%. Mixed effect discrete time survival, binomial and competing risk, models were used to investigate the association between preweaning mortality and farrowing accommodation, controlling for sow parity, litter size and number of piglets stillborn and fostered. There was a reduced risk of stillbirths in outdoor farrowing systems compared with crated systems. Farmers reported that crushing of healthy piglets was the most frequent cause of death accounting for 55% of live born preweaning mortality. There was no significant difference in mortality in live born piglets by farrowing system. There was a significantly higher risk of farmer reported crushing of healthy live born piglets in outdoor arcs compared with piglets reared with sows in farrowing crates and a significantly reduced risk of death from causes other than crushing in piglets reared outdoors or in crate/loose systems compared with piglets reared in crated systems. We conclude that, in the farms in this study, farrowing crates reduced the risk of preweaning live born mortality attributable to crushing but piglets in this system were at increased risk of death from other causes. Consequently crates had no significant effect on overall preweaning mortality percentage. In all four commercial production systems; outdoor, farrowing crates, crate/loose farrowing systems and indoor loose housed systems, there were similar levels of mortality.

Increasing available space in a farrowing crate does not facilitate postural changes or maternal responses in gilts

A study was designed to test the effects of gestation and farrowing accommodation on the postural behaviour and maternal responsiveness of gilts. It was hypothesized that increasing available space would allow gilts to move more easily, facilitating maternal responses. Twenty-four gilts were allocated to either an individual stall or small group for gestation, followed by either a narrow crate (42.5 cm wide), wide crate (80 cm wide) or pen (2.4 m×2.4 m) for farrowing and lactation. Postural time budget and standing and lying behaviour were observed on seven occasions during farrowing accommodation occupancy. Maternal responsiveness was tested on d 2 after farrowing by observing each gilts response to a tape recorded piglet distress squeal, played while she was in the process of lying down. Five days before farrowing (d-5) and one day before farrowing (d-1), postural behaviour indicated restlessness: 65% of time was spent lying laterally, compared to over 80% immediately after farrowing (d 1), and gilts spent about twice as much time standing and sitting on d-5 and d-1 as they did on d 1. Gilts changed posture more than four times as often in the prepartum period than postpartum. This prepartum restlessness was more marked in the wide crate than in the narrow crate or pen, particularly when gilts had gestated in groups. On d-1, gilts in the wide crate spent less time lying in lateral recumbency (55% of time vs. 76%, p<0.01) and more time lying in sternal recumbency (20% of time vs. 10.5%, p<0.05) than gilts in the narrow crate or pen. Occupants of the wide crate displayed more bouts of both kinds of lying (p<0.01) than other gilts, and shorter bouts of lateral lying (p<0.05) than gilts in the pen on d-1. In the wide crate, gilts that had gestated in groups lay sternally for 30% of time prior to farrowing, compared to 10% of time in previously stalled animals (p<0.01), and displayed more bouts of sternal lying (p<0.01). Gilts in the wide crate lay down more slowly (18.2 s) than those in either the narrow crate (13.1 s) or pen (12.0 s), (p<0.05). Wide crate occupants also used the crate side for support during lying down less than half as often as gilts in the other two kinds of farrowing accommodation (on 35% vs. 72–89% of occasions, p<0.01), but use or non-use of a support did not affect time taken to lie down in the wide crate. Maternal response to the squeal playback was very variable, and was not affected by gestation or farrowing accommodation. The widened farrowing crate appeared less comfortable than either the narrow crate or pen, particularly when it followed gestation in a group. Contrary to expectations, increasing the available space in a crate did not facilitate posture-changing behaviour. The importance of controlling for type of gestation accommodation when examining the effects of farrowing housing on behaviour is emphasized.

A Case Study: Fecal Corticosteroid and Behavior as Indicators of Welfare During Relocation of an Asian Elephant

This study was a preliminary investigation of an enzyme immunoassay for measuring fecal glucocorticoid metabolites in a male Asian elephant (Elephas maximus) by investigating changes in behavior and cortisol metabolite excretion associated with a putative stressful event. The study collected fecal samples for 10 days prior to, and 10 days after, 24-hr transport and relocation of the elephant to a new herd. The study measured cortisol metabolites using 2 enzyme immunoassays indicating a 389% and 340% increase in cortisol metabolite excretion following relocation. Maximal cortisol metabolite excretion occurred 2 days after relocation and remained elevated during establishment of the new herd. Stereotypic behavior increased approximately 400% after relocation. The relocation disturbed sleep patterns, the elephant spent less time sleeping during the night, and the elephant slept standing up. These results provide preliminary evidence that noninvasive monitoring of fecal cortisol metabolites can be used to investigate adrenal activity in Asian elephants and may be a safe, practical, and accurate welfare indicator.

Factors associated with preweaning mortality on commercial pig farms in England and Wales

Data from 67 pig farms with a variety of farrowing systems were used to identify factors associated with preweaning mortality in British pig herds. The median mortality reported by the farmers was 10·7 per cent (interquartile range 8·5 to 14 per cent). There was a significantly higher mortality when the pigs were weaned when they were older. A multivariable Poisson model was developed into which the types of farrowing system on each farm and the age at weaning were forced. Factors associated with a lower preweaning mortality rate were insulating the farrowing building, providing extra heat at farrowing, giving the piglets iron injections, dipping their navels, using fan ventilation and using artificial lighting systems. Factors associated with a higher mortality rate were a later weaning age, the use of infra-red lamps rather than other forms of supplementary heat, and the use of a creep without any bedding.

Savaging behaviour in gilts and sows

This study investigated the effects of parity, prior experience, and environmental conditions on the incidence of savaging on seven commercial farms. Results indicated that 3.40% of gilts and 1.22% of sows killed one or more piglets (P < 0.05). Fourteen percent of sows that savaged as gilts also savaged during their second farrowing, compared to 0.8% of sows that had not reviously savaged. The incidence of savaging was similar among gilts during the first (all gilt herd) and second (gilt/sow herd) farrowing cycles. Key words: Savaging, gilts, sows, pigs, maternal behaviour

Savaging behaviour in domestic gilts: A study of seven commercial farms

Piglet-directed aggression at farrowing was investigated on seven large, new pig units. Gilts were subject to a light (continuous or diurnal light) and/or sound (newborn piglet vocalisations or no vocalisations) treatment around the time of farrowing. Behaviour records were collected for the first farrowing of 6625 crossbred gilts. The incidence of savaging, number of piglets affected by it and factors associated with piglet-directed aggressive behaviour were recorded. Piglet-directed aggression was scored as 0 (none), 1 (moderate) or 2 (severe). Effects of the light and sound treatments, situation of the farrowing crate within the farrowing room and time (from first to fourth fill of the farrowing rooms) were examined. Three hundred and thirty-one gilts (5.3%) displayed some degree of aggression towards their piglets (scoring either 1 or 2), while 201 (2.9%) killed piglets.

Risks associated with preweaning mortality in 855 litters on 39 commercial outdoor pig farms in England

A prospective longitudinal study was carried out on 39 outdoor breeding pig farms in England in 2003 and 2004 to investigate the risks associated with mortality in liveborn preweaning piglets. Researchers visited each farm and completed a questionnaire with the farmer and made observations of the paddocks, huts and pigs. The farmer recorded the number of piglets born alive and stillborn, fostered on and off and the number of piglets that died before weaning for 20 litters born after the visit. Data were analysed from a cohort of 9424 liveborn piglets from 855 litters. Overall 1274 liveborn piglets (13.5%) died before weaning. A mixed effect binomial model was used to investigate the associations between preweaning mortality and farm and litter level factors, controlling for litter size and number of piglets stillborn and fostered. Increased risk of mortality was associated with fostering piglets over 24h of age, organic certification or membership of an assurance scheme with higher welfare standards, farmers perception that there was a problem with pest birds, use of medication to treat coccidiosis and presence of lame sows on the farm. Reduced mortality was associated with insulated farrowing huts and door flaps, women working on the farm and the farmer reporting a problem with foxes.