EVALUATION OF DAIRY PRODUCTIVITY AND REPRODUCTIVE ABILITY OF UKRAINIAN BLACK-AND-WITE AND RED-AND-WITE MILK COWS DEPENDING ON THE SELECTIONAL DIRECTION OF HOLSTEIN BREED
Animal Breeding and Genetics
Formation of high-yielding herds is a rather long breeding process (at least 10–12 years), during which animals of the 3rd–4th generation appear. During this period, it is necessary to preserve a certain scientifically justified direction of selection to perform the tasks, the embodiment of which in life is possible only in the presence of a long-term plan of breeding work. Selection of cows for milk productivity primarily depends on the degree of influence on this feature of the main genetic
... d environmental factors, taking into account that you can significantly improve the desired attributes. The purpose of our research was to assess productive and reproductive animal characteristics of Ukrainian red- and black-and-white dairy breeds, search of the most effective breeding methods for improving the reproductive function of cows and heifers. Indicators of economically useful signs of the animals under investigation are calculated according to the data of the primary zootechnical account according to the generally accepted methods of biometric analysis. In the course of the work the genealogical, population, genetic and mathematical methods of studying patterns of inheritance, variability, repeatability, estimation of the genotype of animals and other classical methods of research were used. According to the results of our research, it is evident that the best milk production is characterized by the animals obtained by using the Holstein breed of North American breeds. A well-defined difference of 234 kg is observed in the cows of the Ukrainian black-and-white milk breed, and in the red- and-white peers there is an insignificant difference between the groups. That indicates that the high-level animals of the Holstein breed do not fully realize their genetic potential by productivity. It should be noted that the bloodiness of the North American selection of Holstein breeds in the genotypes of both breeds, in contrast to the diet, had a negative effect on the protein content of milk (milk protein content decreased by 0.5–0.9% In comparison with the animals of the desirable type of daughter from the European bulls of the Holstein breed in the group of Ukrainian black- and red- and-white dairy breeds were significantly superior to or were at the level of the animals of the desired type for fatty milk and milk protein content, unlike the daughters from the bulls of the North American breeding direction. Animals derived from the bulls of the North American breeding Holstein breed had the longest service period 166.1 days, which is 36.4 days more than that of the animals of the same breed, but from the bulls of European breeding Holstein breed (P > 0,05). It was also characterized by a longer give birth period, which amounted to 445.4 days, prevailing at the same time of first-born cows with European genetics of Holstein breed for 36 days (P > 0,05). According to the indicator of reproductive ability of animals of Ukrainian black-and-white milk breeds holsteinized by the European type of breeding Holstein breed have a better result of 0.89 in contrast to the peers holsteinized by the North American type of selection 0,86 (P > 0,05). In the comparative analysis of the correlation of reproductive ability of cows with different genotypic groups of both breeds, the cows with the European type of selection of the Holstein breed are preferable to the parameters of the animals of the desired type. Conclusions. According to the results of the evaluation of milk productivity, the preference is given to the animals obtained from the bulls of the Holstein breed of North American breeding by quantitative indices but this genetics negatively affected the protein content of milk. Compared to the animals of the desired type, – then both breeding directions are considerably inferior to the parameters of the animals of the desired type, but on qualitative indicators of milk productivity the cows from the bulls of European breeding Holstein breed prevail and their peers with the North American selection of Holstein breed and animals of the desired type. According to the performance of the reproductive ability of the daughter of the North American bulls Holstein breed had the longest service- and between the give birth period, and shorter dry period. According to the indicator of reproductive ability, dominated cows by the European type of breeding Holstein breed.