Influence of feeding of mixed-ligande complexes of zinc, manganese and cobalt on cow productivity, feed digestibility and nitrogen metabolism in the last period of lactation

Abstract

Purpose. To study of the effectiveness of feeding high-yielding cows in the last 100 days of lactation of different levels and sources of zinc, manganese and cobalt and establish their impact on milk productivity, feed digestibility and nitrogen balance. Methods. Five groups of highly productive cows (one control and four experimental) of Holstein, Ukrainian red-spotted and Ukrainian black-spotted dairy breeds were selected for the experiment at “Terezyne” farm, Bila Tserkva district, Kyiv region. Experimental cows were fed the same rations. The difference was in different doses of mixed ligand complexes of trace elements in the premix. The control was the optimal dose of mixed-ligand complexes of zinc, manganese and cobalt, which was established in a previous experiment with a concentration of 1 kg of dry matter (DM) of feed, mg: zinc – 50, manganese – 50 and cobalt – 0.78. Results. It was found that the use of different doses of mixed ligand complexes of zinc, manganese and cobalt using Suplex selenium and copper sulfate and potassium iodide in feeding cows in the last 100 days of lactation have differently affected their milk productivity. If 2320 kg of milk was milked from each cow of the control group during this period, then from cows of the 2nd-5th experimental groups – 40-220 kg more. The difference in the average daily milk yield of 4% fat was 0.5-2.67 kg and it was significant (P <0.001). The results of the balance experiment show that the animals of the experimental groups better digested feed nutrients and absorbed nitrogen. Thus, in cows of the 2nd, 3rd, 4th and 5th experimental groups nitrogen was deposited in the body respectively by 2.1, 4.1, 7.3 and 12.8 g more, and it was statistically significant (P <0,05) compared with animals of the control group. Conclusions. The use of mixed ligand complexes of zinc, manganese and cobalt helps to increase milk productivity of cows, reduce feed consumption per 1 kg of product and reduces the need of animals for these elements. The best performance results were obtained in the 4th experimental group, the animals of which were fed with a feed mixture containing 1 kg of DM, mg: zinc – 35; manganese – 35; cobalt – 0.4; selenium – 0.3; copper – 9 and iodine – 0.8.