The aim of this study was to investigate the impact of soy lecithin supplementation in beef cow's nutrition on colostrum composition and serum concentrations of immunoglobulin G (IgG) and serum total protein (STP) in calves. Twenty pregnant Charolaise cows were assigned to two groups. In the supplementation group (n = 10) during the last four weeks of pregnancy, soy lecithin was administrated in an amount of 20 g/cow/day. In both groups, basic composition (protein, fat, lactose, dry matter), somatic cell count (SCC), total bacteria count (TBC), IgG concentration, and fatty acids profile were determined in colostrum samples. Moreover, STP and IgG concentration were measured in calves' blood samples on the 3rd, 7th, 14th, and 21st days of life, mothered by supplementation and control cows. Animals fed with soy lecithin before calving produced colostrum with a higher (p = 0.049) level of linoleic acid (C18:2 n-6). In addition, these results showed that soy lecithin supplementation has contributed to an increase (p = 0.029) of serum IgG in calves on the 14th day of life. The impact of such change in colostrum on IgG levels on calves serum and their half-life need further analysis.
Keywords: blood; calving; nutrition; passive transfer; soy lecithin.