Efficiency of using different levels of mixed ligand complexes of Zinc, Manganese, and Cobalt in cow feeding

To increase productivity and reduce the negative impact on the environment, it is necessary to investigate the most optimal ratios of organic trace elements in the diets of cows involved in the production cycle, considering their physiological state and lactation stage. The purpose of the study was to determine the economic profitability of using mixed complexes of zinc, manganese, and cobalt in the diets of dairy cows. The experiment was carried out under production conditions on Holstein cows. 100 cows were divided into two groups. Cows of the control and experimental groups consumed feed mixtures made according to the same recipes, supplemented with mixed ligand complexes of zinc, manganese, and cobalt. It was found that with the optimal content of mixed ligand complexes of zinc, manganese, and cobalt in cows of the experimental group, body weight loss during the first hundred days of lactation was 16.4 kg or 2.88% less than in the control. Analysis of performance indicators of cows during the dry period and the first hundred days of lactation showed that in animals of the experimental group, whose diet contained mixed ligand complexes of trace elements at the rate of 54.7 mg of zinc and manganese and 0.7 mg of cobalt per 1 kg of dry matter, milk yields of natural fat content increased by 4.1 kg or 9.2%, the fat content in milk – by 0.02% compared to cows of the control group, whose diets provided the content of zinc and manganese at the level of 60.8 mg, cobalt – 0.78 mg/kg of dry matter due to mixed ligand complexes. There was also a decrease in the duration of the service period by 9 days and the insemination index by 0.17 semen doses. The cost of production remained unchanged, and the additional profit with a reduced concentration of these elements in the diet of cows of the experimental group amounted to EUR 27.24 or 9.7%. Thus, optimisation of mineral nutrition of cows by introducing mixed ligand complexes of zinc, manganese, and cobalt to achieve the concentration of trace elements of zinc and manganese – 54.7 mg each, and cobalt – 0.7 mg per 1 kg of dry matter of the feed mixture will improve milk production and reproductive capacity of cows and allow obtaining additional profit