Factors affecting the behaviour and performance of sows and piglets grouped during lactation
Group housing of sows and piglets during the lactation period in a multisuckling system was studied to identify the factors affecting the behaviour and performance of sows and piglets. Comparison was made with sows and piglets in a conventional farrowing pen with crate system. Cross-suckling, additional piglets at the udder during nursing periods, grouping piglets and changing sow location, which might all have contributed to the observed differences in behaviour and performance of the sows and piglets, were each studied separately in more controlled farrowing house conditions. It was shown that welfare of the sow as improved in the multisuckling system as the sows had free movement, expressed more natural behaviour and had social interaction, relative to a sow in a crate. Fighting at grouping was low when using a docile breed (Manor Meishan). The production of the sow was comparable to sows in the conventional system. Welfare of the piglets during grouping was impaired, as they suffered from being placed in a cooler environment (below their Lower Critical Temperature) compared to a conventional farrowing pen with crate system. Piglet mortality rate by being crushed was slightly increased when sows had free movement. Disruption of nursing with adverse effect on the performance of the piglets was observed following grouping with an increased incidence of cross-suckling and a greater number of piglets at the udder during nursing. It can be concluded that grouping sows and piglets during the lactation period can enhance the sows welfare and still provide similar piglet production to the farrowing pen with crate system. However, problems occur for the piglets and good management is needed as the ill-thriving animals are more difficult to identify and treat in such a loose housing system.