Influence of the housing environment during gestation on maternal health, offspring immunity and survival
Résumé
In pig husbandry, pregnant females are often exposed to stressful conditions that may affect their physiology, behavior or health and consequently their offspring ability to survive and develop. This study compared two different housing systems from insemination to 106 days of gestation, a conventional (C) and an enriched one (E), for maternal cortisol and immune parameters, as well as for the immune function and survival of their offspring. C and E systems differed essentially for the housing design (slatted floor, 2.4 m2 per sow vs. a deep straw litter and 3.4 m2 per sow). Results from Exp. 1 (n = 108) demonstrated that C sows had higher salivary cortisol than E sows at gestational day 102 (DG 102). Results from Exp. 2 (n = 48) showed that, at DG 102, C sows had higher granulocyte counts and total plasma immunoglobulin G (IgG) concentration than E sows, whereas lymphocyte number, haematocrit and haptoglobin plasma concentration were similar. Results from Exp. 3 (n = 47) showed that plasma IgG level at 5 and 27 days of age, hematocrit, white blood cell numbers and in vitro lymphocyte proliferation of piglets at 27 days of age were not influenced by maternal housing conditions. However, reproductive data collected in Exp. 2 and 3 indicated that pre-weaning mortality was higher in C than E litters. In conclusion, the C system was associated with markers of increased stress and microbial aggression in gestating sows, and with greater piglet mortality during the suckling period without identified alterations in piglet immune function.