GENETIC CONDITIONS OF COWS REPRODUCTIVE SYSTEMS DISEASES IN SUBPOPULATIONS

Abstract

As a result of the studies, the relationship of reproductive traits with adaptability was revealed, which were characterized by low heritability and were subject to inbred depression. Selection rates increased from generation to generation by an average of 13.8 %, but did not always lead to changes in disease rates. The correlation coefficient between milk yield of cows during the first 305 days of lactation and service period was -0,227± 0,013 (F test of 5.2), the coefficient of the linear regression of service period on milk yield for 305 days of first lactation – 0,45±0,033. A positive correlation (r =+52±0,012) was revealed between the milk yield of full-aged cows during 305 days of lactation and the number of cows eliminated due to infertility. Genetic and environmental factors together exceeded the threshold of adaptability, so the body's ability to resist became weakened. The correlation coefficient for daughter-mother for the duration of the disease +0,33±0,022, age of animals at the beginning of the disease – +0,36±0,021. Coefficients of repeatability gynecological diseases in cows from the first to the second lactation + 0,807, from the second to the third + 0,892, from the first to the third – + 0,454. From the data obtained, it follows that heritability depends on factors, each of which has a relatively small impact on variability and is determined by many genes. Features with a threshold deviation are not related to the efficiency of selection by productivity. Gynecological pathologies in offspring arise under the influence of different alleles systems.