Digestibility and nutrient utilization in replacement heifers when feeding a complex mineral feed additive

The purpose of research is to study the level of digestibility and the use of a wide range of food additives (KMKD). Scientific and economic experiments on the production of useful black-and-white calves are being carried out on the basis of OOO Valiev Breeding Plant (limited liability company) in the Dyurtyulinsky District of the Republic of Bashkortostan. 3 groups of replacement heifers were selected according to the method of pair-analogues (10 heads in each): same age (7 months), live weight (average 160-163 kg). The duration of the experience is 90 days. Calves of the control group of detection of the main diet (RR), found in agriculture, and individual mineral supplements according to the standards of A.P. Kalashnikov (feed chalk, table salt, defluorinated phosphate) mixed with feed; I of the experimental group - OR + KMKD according to prescription No. 1 (50 g/animal per day); II of the experimental group - OR + KMKD according to prescription No. 2 (50 g/animal per day). KMKD recipes differed only in the percentage of their ingredients. The use of CMFA in the diets of animals of the I experimental group contributed to the improvement of the digestibility of dry and organic matter, crude fiber and BEV, but these data were not reliable during static processing, reliable results were obtained for the digestibility of crude protein by 2.9 % and crude fat by 3.1 % (P ˂ 0.05) is higher than in the animals of the control group. Digestibility coefficients of nutrients in animals of the II experimental group are significantly higher in comparison with the I experimental group - by 2.2; 1.3; 1.1; 1.7; 2.8 and 1.5 %, respectively, there were also more significant differences in the digestibility of nutrients in comparison with the animals of the control group. So, the digestibility coefficients are significantly higher: in terms of dry matter - by 3.5 %; for crude protein - by 4.0; crude fat - by 4.8 and crude fiber - by 4.9 % (P ≤ 0.05). Feeding KMKD according to recipe No. 2 to replacement heifers aged 7-9 months had the most positive effect.