Effect of the diets with pumpkin silage and synthetic β-carotene on the carotenoid, immunoglobulin and bioactive protein content and fatty acid composition of colostrum

Forty Simmental cows were divided into four groups with 10 per group to investigate the effect of a transition diet supplemented with synthetic β-carotene and natural carotenoid-rich feed (pumpkin silage) on chemical composition of the colostrum. The control group (I) was fed grass and maize silage and supplemental concentrates, group II additionally received 400 mg/day/cow of synthetic β-carotene, in group, III 40% DM of maize silage was replaced with pumpkin silage to increase β-carotene intake by 400 mg in relation to group I, and in group IV 60% DM of maize silage was replaced with pumpkin silage without adjusting for β-carotene. Colostrum was collected from the cows within 5 hr of calving to determine colostrum composition, the content of immunoglobulins and carotenoids, total antioxidant status (TAS), the content of some bioactive proteins and the composition of fatty acids. The study showed that the experimental diets had no effect on the gross composition of colostrum. The content of α-carotene, β-carotene and violaxanthin was significantly higher in group IV than in group I and that of lutein higher in group IV than in groups I and II. Total antioxidant status of colostrum in group IV was significantly higher than in group I. Groups III and IV were characterized by a higher concentration of immunoglobulin IgG in relation to group I. IgM level in groups II, III and IV was significantly higher than in group I and that in groups III and IV was also higher than in group II. The highest IgA concentration was observed in group IV and the lowest in group I. Lysozyme concentration was higher in group IV compared to groups I and II. The diets had no effect on the total content of SFA, MUFA and PUFA in colostrum.