The influence of coniferous-mineral additives on the milk productivity of first-calf heifers under conditions of Yakutia

The purpose of the work is to study the complex effect of coniferous-mineral additives on the digestibility of nutrients and milk productivity of first-calf heifers of the Simmental breed in the conditions of Yakutia. The study was carried out according to generally zootechnics methods: selection and experimentation, physiological experiment, analysis of milk productivity. The inclusion of coniferous-mineral additives it possible to increase the milk productivity of experimental animals by 6.35 and 8.31%, respectively (P0.999). At the end of the scientific experiment, milk yield in the experimental groups was higher by 58.2 and 75.0 kg (or 6.44 and 8.30%). At the same time, in the milk of the experimental groups the content of the proportion of milk fat increased by 0.08 and 0.10%, as well as the content of the proportion of milk protein by 0.05 and 0.08% relative to the control group. Changes caused by the inclusion of experimental feed additives in the diets of first-calf heifers were reflected in the indicators of nutrient digestibility, where in the second and third experimental groups there was an increase in dry matter digestibility by 2.29% (P0.95) and 2.94% (P0 .99), organic matter by 1.36 and 2.83% (P0.95), crude protein by 2.03 and 2.94% (P0.95), crude fat by 2.47 and 3 .12% (P0.95), crude fiber by 0.43 and 3.81% (P0.95), nitrogen-free extractives by 0.53 and 1.44% (P0.99), respectively compared to the first control group. Thus, the complex use of local non-traditional feed additives helps to increase the degree of digestibility of nutrients and increases the milk productivity of animals in the conditions of Yakutia.