Plasma cortisol levels in suckling piglets fed functional foods

Abstract

Stress in piglets is a crucial factor that can affect their well-being and performance from birth to weaning. During farrowing, piglets face physical and psychological challenges with the abrupt change from the intrauterine environment to the external environment. Lactation is a source of stress due to competition for feed, crowding, and constant handling by the mother or handling personnel. Variation in cortisol levels, as an indicator of stress, was studied in suckling piglets with access to two pre-starter diets: a control diet (C) and a supplemented diet containing potato protein concentrate and Saccharomyces boulardii (CPP-Sb) as functional feeds (FF). Sixty piglets from six litters, weighing 1.422 ± 0.277 kg, were used. They had free access to colostrum and maternal milk for 21 days. From day 7 to 21 pre-starter diets were offered to the piglets. Two piglets (one male and one female) per litter per diet were randomly selected for blood sampling at birth (via the umbilical cord) and on days 7, 14, and 21 by jugular vein puncture. Samples were collected in tubes with EDTA anticoagulant, plasma was obtained, and cortisol was measured by ELISA. Diet did not affect (P>0.05) cortisol levels (20.1 ng/ml, on average), nor was there any interaction between diet and day of lactation (P>0.05); however, a day effect was observed (P=0.0001), with concentrations increasing between birth (17.1 ng/ml) and day 21 of lactation (25.2 ng/ml). The values obtained were lower than those reported in the literature. The addition of AF to the pre-starter feed did not reduce the increasing stress in lactation, probably due to the low feed intake during lactation.