Effects of early socialization by mixing with different litter during suckling period on behavior and growth rate of piglets

[Abstract] In order to reduce the mental and physical distress at weaning on piglets, the effects of early socialization by rearing with different litter mixtures during the suckling period were studied. Newborn piglets were reared in both group-farrowing (Exp. group) and ordinary-farrowing systems (Cont. group) during the suckling period and regrouped after weaning. Production performances were almost the same in both groups. Agonistic behavior between piglets toward members of the other litter was observed more frequently than toward littermates after weaning, especially in the control group. Skin damage of the control group was worse at five weeks of age, immediately after regrouping. Thus, early socialization by mixing with different litters within two days after birth might reduce the distress of weaning and increase the welfare level.