Effect of bovine colostrum on the serum insulin-like growth factor-I (IGF-I), the IGF binding proteins-2 and -3 and the thyroid hormones in weaning piglets

This study examined the effect of a bovine colostrum supplementation on growth performance, feed intake and the hormonal response of piglets at weaning. Ninety-six newly-weaned piglets were assigned for four weeks to one of the two treatments: Control (diet with bovine milk whey) and Colostrum (diet with bovine colostrum whey) treatments. The supplements were incorporated in a commercial diet at 20 g/kg during the first 2 weeks after weaning and lowered to 10 g/kg for the next 2 weeks. Body weight and feed intake were measured weekly. Blood samples were taken weekly for determination of circulating IGF-I, its binding proteins and the thyroid hormones (T3 and T4). During the first week of the trial, the Colostrum-fed piglets presented improved growth performance, feed intake and feed efficiency and a higher concentration in circulating IGF-I (+15 %) compared to the Control piglets. In both treatments, the circulating thyroid hormones were reduced by weaning and the levels measured at weaning were recovered earlier by the Colostrum-fed piglets compared to the Control group (P<0.05). It is concluded that hormonal response observed after the bovine colostrum supplementation is, at least in part, consequent of the positive action of bovine colostrum on the feed intake.