Weaned piglets fight with each other in order to create a stable social group. One way to solve this is to let piglets socialise early. French researchers wanted to check if this method was practical to use on farms and if it lessened the negative impact on behaviour, lesions and growth performance.
The trial was carried out on 600 sows at a farrow-to-finish farm in France. Both the test group and the control group the sows were kept in standard closed farrowing crates. The control group were kept in the usual way at this farm, whereas in the test group, sliding doors of 21x20cm were created in the farrowing pen walls, which were opened 5 days after birth. This way, the piglets were able explore all the pens freely.
Piglets were raised and treated in the usual way for the farm, with the exception of being ear tagged for individual identification. Piglets were weaned at 21 days after birth, then moved to a nursing facility where they stayed for 15 days. The 2 groups, test and control, were placed in the same nursery room, each at one side of a central corridor and were divided into four pens. They both received the same feed ad lib.
Piglets who presented health issues were moved to the infirmary and treated. The piglets were weighed 2 days after birth, at weaning, and 12 days after weaning. The feed distributed in nursery was weighed also. The proportion of piglets with skin lesions and severity of lesions were measured 2 days after opening the doors in the farrowing facilities, at weaning and 3 days after weaning. The same observer took the measurements each time.
No differences were found between the socialised and control group for after birth and weaning mean weight (1.2 kg and 7.0 kg respectively), but socialised piglets weighed 1 kilo more 12 days after weaning (13.2 kg in test group versus 12.2 kg). This result is coherent with feed intake: plus 1.1kg of feed per piglets on average for the test group versus control. Skin lesions were different between the groups: 98% piglets had skin lesions 3 days after weaning in the control group against 40% in test group. No deep lesions and no bleeding lesions were observed in the test group, whereas 3% of skin lesions were classified as deep in the control group with many consequences on health like infections and arthritis. The piglets in the control group fought 6 times more and their fights lasted 4 times longer than the socialised piglets. Some fights lasts for more than 3 minutes with no interruption in the control group, whereas no fight lasted longer than 4 seconds in socialised group. The results from this field trial are really encouraging and provide an encouragement to implement this method on more and more farm, as this is a step towards better welfare for pigs and for farmers.
Authors: Alexis Nalovic and Dominique Marchand, veterinarians, Epidalis Reseau Cristal, France