The dissertation presents the results of studying the features of the exterior type of dairy cattle of domestic breeds in relation to their productivity, duration and efficiency of life use, the correlation of the development of linear traits with the determination of population and genetic parameters. A complex determination of breeding and genetic aspects of the formation of cattle breeding of Ukraine at the present stage of improvement of Ukrainian Black-and-Red and Red-and-White dairy breeds has been carried out.
The peculiarities of formation of dairy productivity of cows of specialized dairy breeds were investigated, the degree of influence of genotypic factors on its realization was determined. The characteristics of the cow's exterior were measured in terms of measurements and body structure traits indices in lactation dynamics; the variability of body structure and productivity of cows of different exterior-constitutional types were studied. The features of the exterior type of cows evaluated by the linear classification method were investigated. The degree of influence of linear traits of the exterior on the development of dairy productivity of first-born cows of Ukrainian dairy breeds was established. The degree of inheritance and influence of hereditary factors on the exterior type of cows was investigated.
The indices of longevity and life productivity of cows of Ukrainian dairy breeds in the aspect of influence of genetic and paratypical factors were evaluated. The influence of estimation of linear type traits on the life expectancy of cows was analyzed.
Assessment of offspring of genealogical formations confirmed the influence of linear affiliation on the level of dairy productivity of cows of the studied breeds. In breeding herds of the Ukrainian Black-and-White dairy breed, the best lines were: Inhanse 343514, Valiant 1650414, Starbuck 352790 and P.F.A. Chif 1427381, Ukrainian Red-and-White dairy breed – Eleveyshn 1491007.
The dependence of dairy productivity of crossbred cows on the conditional share of heredity of Holstein breed is proved. The difference in favor of animals with Holstein hereditary 87.6 -100% in comparison with the groups of first-borns with lower blood count was 263-2429 kg (Ukrainian Black-and-White dairy breed) and 451-1336 kg (Ukrainian Red-and-White dairy breed).
The obtained coefficients of the force of influence of paratypical factors testify to the influence on the milk yield of the first-born cows of the year of birth and calving. Of the genotypic factors, the most significant influence on the milk yield and fat content of milk has the breeding value of the cow's parents.
An evaluation of animals of different exterior-constitutional types found that leptosomal type first-born cows had significantly higher yield of 537 kg (Ukrainian black-and-white dairy) and 472 kg (Ukrainian red-and-white dairy) than peers of erysomal.
There is a positive correlation between the milking of first-born cows and the group and descriptive traits of linear classification. The inheritance of group exterior traits varied from h2 = 0.242 to h2 = 0.356. The force of influence of the breeding value of the father in the overall share of variability of linear traits was 37.1-41.8%, the conditional blood count of the Holstein mother breed – 24.9-31.5, the father's line – 3.4-29.5.
Indicators of productive longevity of cows of domestic dairy breeds testify to the hereditary influence of the conditional blood count of Holstein breed, genealogical formations and individual heredity of sires on their variability.
The dependence of indicators of duration of use and life productivity on the paratypical factors was revealed. The impact of the year of birth on the life expectancy of cows was 24.4%, economic use – 21.7%, lactation – 13.1%, yield for one day of economic use – 36.7% and lactation – 22.6%. A correlation between the descriptive traits of the exterior and the life expectancy of the cows was determined.
Keywords: breed, line, yield, exterior, linear type estimation, duration of productive use, lifetime productivity, selection, genotype, variability, correlation, inheritance, power of influence.
