In pig farming, weaning remains a critical period characterised by reduced feed intake and growth of piglets. The aim of this project is to reduce weaning stress through group rearing of piglets in the farrowing pen (multisuckling) and thus improve the zootechnical performance of piglets after weaning.
Trial for weaning
To check this effect in practice, group rearing was applied in an initial treatment by opening pen partitions between 2 to 3 farrowing pens 5 days after the last sow had farrowed (VBK group). This treatment was compared with the control treatment (CON group) where piglets were raised in a conventional manner during the farrowing period. Weaning took place at 28 days of age in both groups.
From the results of this project, it can be concluded that free-range piglets in the farrowing pen have a positive impact on average daily growth, feed intake and social interaction between piglets. These piglets get the opportunity to socialise in the farrowing pen with piglets from other litters. At weaning, there is thus one less stressor that can positively influence production parameters and behaviour. Group rearing, on the other hand, does have a negative effect on piglet dropout and number of muzzle injuries in the farrowing pen. It is believed that competitive amount for a weaning can cause piglets to stay away from the udder which can lead to weight loss, weakness and higher mortality rates. On the other hand, group rearing is an advantage for piglets whose mother sow produces too little milk or has too large toms.
Trial after weaning
Afterwards, 11 piglets from 3-5 sows of each treatment each time entered the piglet pen in 1 pen. The piglets from the VBK group were already mixed during rearing, the piglets from the CON group were mixed in the piglet pen. Finally, a trial design with 13 sows with 143 piglets and 17 sows with 187 piglets, for treatment CON and VBK, respectively, was obtained.
It can be concluded that group rearing of piglets in the farrowing pen can positively influence growth. A higher feed intake was realised in the first week after weaning in the VBK group, although at the end of the rearing period no difference in body weight between piglets of the 2 treatments was observed anymore. This shows that group rearing can potentially reduce weaning stress in piglets, but the effect is still rather limited. Group rearing especially has a major impact on the social development of piglets. In this study, group rearing was associated with fewer skin lesions in piglets after weaning, which may indicate that less fighting behaviour occurred at weaning. It is likely that the reduction of weaning stress, and more specifically the reduction of social stress, is the major explanation for the positive effect of group rearing on the zootechnical performance of piglets after weaning.
