THE INFLUENCE OF THE FATHER'S GENETYPE ON THE PRODUCTIVITY OF COWS AND THE PROBABILITY OF THEIR MASTITIS UNDER DIFFERENT HOUSING
Authors: Admin O. E. , Admina N. G. , Rus’ko N. P. 
Published: July 2023

Introduction. The purpose of the study was to determine the influence of genetic factors on the productivity of cows and the probability of their disease with mastitis under different housing technologies.

Materials and methods of research. The work was carried out according to the data of two breeding plants for the breeding of the Ukrainian black and white dairy breed with free and stall housing. The data of more than 16,000 milk samples over the past six years were analyzed. Heritability of the average indicators of the quantity and quality of milk of cows according to the data of control milkings, yield for 305 days of lactation and the number of cases of diagnosis of mastitis using correlation analysis. Variability of milk quality of cows was monitored depending on the technology of housing. The research determined the influence of breeding bulls and their line on milk yield and milk quality indicators. To determine the influence of these factors, dispersion analysis was used. Processing of the obtained data was carried out according to basic statistical techniques using computer programs.

Research results. According to the research results, it was established that the variability of daily milk yield during free housing was higher by 6.1%, fat content by 7% compared to stall housing, and protein content, the number of somatic cells and their evaluation was lower. The strength of the influence of housing on the parameters of daily milk yield was: on the daily yield – 1.8%, on the fat content – 22.8%, on the protein content – 0.8%, on the number of somatic cells – 1.6%, on their evaluation – 4.1%, on the reliability of cows for 305 days of lactation – 4.1%, on milk fat output – 13.6%, on milk protein output – 6.3%, on the frequency of mastitis diagnosis – 4.5%. The coefficients of heritability of daily milk yield under stall housing were 2.2 times higher, fat content – 3.5 times, protein content – 1.8 times, number of somatic cells – 2.7 times, estimates of the number of somatic cells – 2 times, milk yield for 305 days of lactation – 2.4 times, the amount of milk protein – 1.6 times, and the number of cases of mastitis diagnosis – 1.7 times. The influence of bulls on indicators of the quantity and quality of cow milk was significantly higher than on daily milk yield. The strength of the influence of this factor on indicators of daily milk yield during free housing was: the milk yield – 5.5%, the fat content – 2.5%, the protein content – 2.7%, the number of somatic cells – 2.5%, the estimation of the number of somatic cells – 2.8%, and for stall housing – 4.3%, 6.7%, 6.7%, 2.9%, 7.3%, respectively. The strength of the influence on productivity indicators per lactation was as follows: for free housing on milk yield – 13.4%, on the amount of milk fat – 20.1%, on the amount of milk protein – 13.5% and on the number of cases of mastitis diagnosis – 12.7%, and for stall housing 19.1%, 13.6%, 18.0% and 35.2%, respectively (Р < 0.001). The influence of the factor "bull" was higher than the "bull line" factor on indicators of physical and chemical properties of milk and the frequency of cases diagnosis of mastitis in their daughters.

Conclusions. The housing technology has a significant impact on the productive indicators of dairy cows, their variability and heredity. For free housing of cows, the genetic conditioning of indicators of productivity and milk quality of cows, the probability of their mastitis disease was lower in comparison with stall housing.