Scientific Journal of KubSAU

The analysis of productive qualities of descendants of bulls of various linear kind has been presented in this article

The effect of the level of milk production of firstcalf heifers on the further productivity, reproductive function and duration of economic exploitation of holstein cows in southern Russia

In the article we have studied the exterior of golshtinizaited animals. The increase in number of measurements for specific dairy type and increase of productivity has been established

The behavior, interior and milk yield of the mature Black-and-White cows with various productivity levels, as well as etology of the replacement heifers are researched. The superiority of the high milk yielding cows for the lying duration and eating feed and water is revealed. Reduced variability of vital behavioral actions of animals is found. In addition, high yielding cows has been lower variability in all feeding acts. It was noted that high yielding animals exceeded equal age cows by the level of most interior factors. The differences were significant on the content of hemoglobin, vitamin E, and especially on the content of iron. Positive correlations between some interior design indicators is found. The analysis of lifetime productivity during our research found that high milk yielding cows had highest yields on the first lactation and kept the same level in the next lactations with insignificant variations. The lower productivity animals reached maximal yields on the third lactation with the followed downward trend. Differences between groups in lifetime productivity during research amounted to 16 992 kg. The significant superiority of the heifers with high grown intensity above equal age animals for the duration of feed and water eating, physiological functions and lying. The analysis of variation coefficient is confirmed the observed regularities.