Comparative assessment of the daughters of servicing bulls of foreign breeding on dairy productivity

Abstract

Prolonged Holsteinization led to the absorption of the domestic dairy black-and-white Holstein breed. Currently, the widespread use of bulls of various Holstein breeds continues and the study of their effect on the productive qualities of daughters is relevant and has practical significance. It was found that the daughters of the Brandy bull were obtained by outbred selection, and the daughters of the Bourbon and Dancer bulls have an inbreeding level of 0.47-0.39, which allows them to be classified as a group with a moderate inbreeding degree. The daughters of all bulls showed high milk yields in 305 days of the first lactation. In terms of milk quality, they exceeded the standard requirements. The highest productivity indicators - milk yield for 305 days of lactation were found in cows - daughters of the Brandy bull - 9825.7±927.14 kg, which is 502.7 and 473.3 kg more, or 5.1 and 4.8%, respectively, for groups of daughters of other bulls. The evaluation of milk physical and chemical parameters confirmed the superiority in nutritional and biological value of the product obtained from the daughters of the Dancer bull. It had more dry matter and fat in milk, which led to an increase in nutritional value.