Effects of gestation housing system on maternal stress, piglet maturity at birth and early survival
Résumé
Sow housing and management system can generate maternal stress which could influence piglet development during gestation and postnatal survival. We investigated the effects of two housing systems for gestating sows on piglet maturity at birth and early survival. Gestating sows were group-housed in a conventional system on slatted floor (C, n = 49) or in larger pens enriched with straw bedding (E, n = 57). On gestation day (DG) 105, all sows were transferred into farrowing pens on slatted floor. Piglet mortality was recorded in all litters and saliva cortisol in all sows, while neonate and lacteal traits were investigated in a subset of litters and sows (C n = 18, E n = 19). Concentrations of cortisol were greater (P < 0.001) in C than in E sows on DG 35 and 105 but no longer after the transfer to farrowing crates on DG 107 and day 4 of lactation. Mortality rates were greater amongst C piglets, especially within 3 days post-partum (13.6 vs. 6.3%, P < 0.001). System did not alter piglet weight at birth but gut weight was lower (P < 0.05) in C piglets. The C piglets also had greater plasma concentrations of fructose (+13%), lower concentrations of glucose (-9%) and lower glycogen content in muscle (-8%) (P < 0.05), suggesting a lower maturity of C piglets. However, other tissue indicators of physiological maturity did not differ between C and E neonates. The housing system neither influenced piglet weight gain over 24 h from birth nor altered nutritional composition of colostrum and milk collected at day 4 of lactation, the exception being protein content that tended to be greater in colostrum from C sows (P = 0.07). To conclude, the conventional system during gestation induced maternal stress and greater neonatal mortality, without major effects on piglet physiology at birth. Research was funded by the EU FP7 Prohealth project (no. 613574).