The effect of different levels of vitamin A in the diets of bulls fed with food industry waste on the change in the metabolism of nitrogen, calcium and phosphorus

Abstract

The article gives the results of studying the metabolism of nitrogen, calcium and phosphorus in the body of black-and-white bulls fed with waste from the food industry (barda, pulp, beer pellet) with different levels of vitamin A. Studies have shown that the vitamin A content in the diets of bulls in accordance with the recommended standards of the Russian Academy of Agricultural Sciences for carotene does not contribute to better deposition of nitrogen, calcium and phosphorus in their bodies. Normalization of these elements metabolism in the body of experimental bulls occurs due to the additional introduction of the vitamin preparation “Microvit A” into their diets and due to an increase in the amount of vitamin A when fattening using stillage and pulp by 50%, when fattening on diets with brewer's grains - by 40% more recommended standards of the Russian Academy of Agricultural Sciences for carotene. For all types of fattening, the best absorption of nitrogen, calcium, and phosphorus into the body was in the experimental group III. Nitrogen retention in their body when fattening on stillage was by 4.99 g, or 19.8% (p<0.05), calcium - by 1.55 g, or 14.6% (p>0.05 ) and phosphorus – by 1.64 g, or 19.9% (p<0.05) higher than in control peers from group I. The enrichment of these elements from diets with pulp and brewer's grains in animals of experimental group III was also higher than in control analogues from group I.