Mother-young relationships in pigs : from birth to weaning

Abstract

Modern production methods can induce negative consequences for pig welfare. In wild-pigs, as in domestic pigs reared in natural conditions, parturient females live in a matriarchal group and build a nest to protect their piglets. A selective bond is established between sows and piglets, and suckling continues for a minimum of 10 to 12 weeks. Present rearing conditions have largely modified the life of pigs. Generally, sows are kept in individual pens and can not build a nest. During the suckling period, contacts between the sows and piglets are reduced and only initiated by the young. However, vocal and olfactive exchanges help piglets localise the teats and induce a reciprocal recognition between mother and young during the first 48 hours post partum. The absorption of colostrum as soon as possible after birth is essential for immunity protection and nutrition. The rate of suckling is approximately once per hour during the first weeks of lactation, then it decreases progressively. During the first days post partum, piglets develop a preference for the teats after intensive fights. The attachment between mother and young is not as selective as in ruminating animals. Fostering of piglets is easy when they are less than three days old. Later, adoptive sows accept foreign piglets with difficulty and the young do not attempt to suck for the first hours, or even days. However, the substitution of an entire litter is easily accepted by the sow, even after 3 weeks of nursing. In most cases piglets are weaned at 4 weeks. Weaning before that time is not permitted in intensive breeding, unless health reasons require that the piglets be weaned when they are only one week old. Behavioural and zootechnical disturbances appear correlated with the precocity of weaning. In modern husbandry, the welfare of animals is respected and an attempt is made to avoid anxiety-producing situations and to permit normal behaviour of the species.