BALANCE OF MINERAL ELEMENTS IN THE BODY OF YOUNG CATTLE WITH DIFFERENT SOURCES OF SELENIUM IN THE DIET

Abstract

The data of the study of the influence of different sources of selenium in the diet on its availability to the body, on the balance of calcium, phosphorus, sulfur, copper, zinc and selenium itself in the body of experimental heifers are presented. It was found that an increased level of selenium in the diet (0,3 mg/kg of BDW) contributed to better deposition of calcium in the body of experimental young animals. In heifers of the experimental groups, compared to the control, less calcium was excreted in feces by 0,76–4,3% and in urine by 10,8–16,5%. Moreover, the lowest urinary calcium excretion (0,79 g) was observed in heifers of the 4th experimental group, the source of selenium in the diet of which was selenomethionine. The lowest urinary phosphorus excretion was observed in heifers of the 4th experimental group, which received organic selenium in addition to the diet. However, in terms of urinary phosphorus excretion, the heifers of the 3rd experimental group were not much inferior to the animals of the 4th experimental group – only 0,02 g, or 2,1%, and the heifers of the 3rd experimental group – by 0,07 g, or 7,4%. Unlike calcium and phosphorus, the dependence of sulfur metabolism on both the level of selenium and its source was noted in the metabolic experiment. The experimental heifers differed from the control analogues in the relative indicators of sulfur absorption in the body from its consumed amount by 4,64–5,80%. It should be noted that the lowest endogenous urinary sulfur excretion and the highest balance were noted in the heifers of the 4th experimental group, slightly lower in the animals of the 3rd, and even lower in the animals of the 2nd experimental group. The experimental heifers differed from the control in a better copper balance. Among the 3 experimental groups, heifers of the 4th experimental group were characterized by the lowest urinary copper excretion and a higher balance, although the difference in these indicators between the animals of the 2nd and 3rd experimental groups is significant. Among the experimental groups of heifers, the 4th experimental group with the content of selenomethionine in the diet was characterized by lower zinc excretion and a higher balance, although the difference in indicators between the 2nd and 3rd groups was not significant. In control animals, the selenium balance was only 0,004 mg), and in the experimental animals it was 173,5–189,8 times higher. Relative selenium absorption rates were higher in animals of the 4th and 3rd groups (35,1 and 33,4 versus 30,0%).