Browsing by Author "Chidgey, Kirsty Laura"
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- ItemThe productivity and behaviour of sows and piglets housed in farrowing pens with temporary crating or farrowing crates : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science, Massey University(Massey University, 2016) Chidgey, Kirsty LauraPen-based alternatives to farrowing crates have been researched for decades, in an effort to improve the welfare of farrowing and lactating sows. However, high piglet mortality, and a lack of commercially-relevant studies, has been a barrier to the acceptance of these systems in the pork industry. The purpose of this thesis was to compare the performance and behaviour of sows and piglets in farrowing pens with temporary crating, and in farrowing crates, in a commercial setting. In the first study, sows were housed in either a farrowing crate from 5 days pre-farrowing until weaning at 28 days; or in a pen where sows were crated from 3 days pre-farrowing until the 4th day of lactation. The farrowing system (crate or pen) from which a sow was weaned had no effect on subsequent reproductive performance. However, pre-weaning piglet mortality was significantly higher in pens (10.2%) than in crates (6.1%). Sow and piglet behaviour was studied during the first 6 days post-farrowing in the second study. Sows in crates were confined throughout this observation period, whereas sows in pens were crated for days 1 – 3 post-farrowing and loose in the pen during days 4 – 6 post-farrowing. There was no difference between systems for the amount of time sows spent lying or standing during days 1 – 6, though sows in pens were more active once they were loose. Penned sows touched and investigated their piglets more once they were loose, compared to when they had been crated. There were few differences in piglet behaviour between farrowing systems. The influence of the birth and rearing location (crate or pen) on gilt behaviour was examined in the third study. Gilts were identified as having been born and reared in a farrowing crate or in a pen. Gilts and their piglets were observed during the first three days after giving birth in the system they were born and reared in, or in the system they were not born and reared in. Gilts born and reared in pens with temporary crating touched and vocalised towards their piglets more than gilts born and reared in farrowing crates, irrespective of whether they farrowed in a crate or a pen. This finding has implications for the transmission of maternal behaviour. The associations between sow behaviour, gilt behaviour and piglet behaviour were compared in farrowing crates and pens with temporary crating using the data of the second and third study. Some associations between sow and piglet behaviour changed when the sow was no longer confined in a crate. This finding could be the link that explains differences in the later behaviour of gilts that were reared in different systems. Future studies should focus on the transition period between a sow being crated and then let loose in a pen, to improve sow and piglet welfare in these systems.
- ItemThe welfare and productivity of dry sows in different group housing systems in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Palmerston North, New Zealand(Massey University, 2011) Chidgey, Kirsty LauraThis research aimed to take a holistic approach to assessing dry sow welfare in relation to gestation accommodation. Multiple factors that affect the welfare of a sow were considered. In addition, the multitude of systems in New Zealand that are used to accommodate dry sows in groups were captured. Commercial pig farms (n=20 farms, 7,912 sows total) were chosen to represent the spectrum of different layouts and management practices in order to obtain data from a wide range of different systems. During each on-farm visit, data concerning housing, management, sow behaviour, welfare and productivity were collected. A number of criteria were used to describe the farms (group size, stall duration, presence of bedding, feeding method, feeding frequency). Sows kept in stalls for more than 5 weeks (n = 3 farms) had significantly higher injury scores than sows that were in stalls for a shorter length of time or sows that were not kept in stalls for any period during mating or pregnancy. Sows fed twice daily had significantly higher stereotypies (P<0.05) than those fed at a different frequency. A welfare index (WI) was calculated for each farm. This index incorporated each farm‟s total scores for injuries, stereotypies, coat condition, soiling and lameness. A low WI represented a lower presence of indicators that were associated with compromises to welfare. Hence, a low WI represented good welfare. For each farm, the minimum possible WI was 0.33, whilst the maximum possible WI was 5.0. The mean WI was 0.65 (±0.14 SD). Overall, there was not a high prevalence of indicators of compromised welfare. Out of the 20 farms, with an average herd size of 395.60 sows per farm; only 10 sows in total were lame. Only three farms had sows with a coat condition score above 0 (normal). There was no difference between mean piglets born alive per litter (BA) for stalls (12.65±0.36) vs. group housed sows for the entire gestation (12.27 ± 0.43) , or for the number of piglets weaned per sow per year (stalls: 23.70±0.59 W/S/Y, groups: 24.92±1.23 W/S/Y). As a result of this study, it is clear that there is no perfect or ideal system for keeping dry sows, because a sow‟s needs change throughout different stages of the production cycle. Therefore the implication is that in any housing system, both the advantages and disadvantages relating to a sow‟s welfare will also change over time. In light of this, operators need to understand the variation both between and within systems and how best to manage them.