DAIRY PRODUCTIVITY AND EXTERIOR TYPE OF FIRST-CALVE COWS OF UKRAINIAN BLACK-AND-WHITE DAIRY BREED DEPENDING ON UDDER-MASO-METRIC INDEX

Abstract

The theory and practice of breeding show that optimal results can be achieved by a complete evaluation of the genotype. The leading method of such an estimation is an index expression, which accumulates in one indicator the optimal ratio of breeding signs. In this aspect, it is important to use the breeding indices, which are estimated by the exteriors of animals, since breeding only on the indicators of milk productivity, namely on the level of fertility, contributes to the degradation of reproductive ability and, generally speaking, to the early extinction of the herd of animals. This determines the relevance of our work. The aim of the work was to study the effectiveness of selection first-born cows by the udder-mass-metric index in the herd of Ukrainian Black-and-White dairy breed.The research was carried out on 198 first-born cows Ukrainian Black-and-White dairy breed PAC "Yerchi". We used the basis of breeding records and the results of their own research.The differentiation of cows by the size of the wizard-mass-metric index was carried out according to the methodology of O. P. Polkovnikova wiith co-authors. Groups are conventionally called early, optimal and late.The results of our research showed that the first-born cows of the Ukrainian Black-and-White dairy breed, separated by the size of this index, significantly differ in their complexes features of the 100-score system of linear classification of the exterior type. The studied animals of the three groups for all the complexes of the 100-score system received rather high ratings: from 78.8 to 81.9 points, which corresponds to the classes "good" and "good with the plus" in accordance with international requirements.In general, there is a clear tendency that with an increase in the value of the udder-mass-metric index there is an increase in the overwhelming majority of complex features of linear classification, except for the complex features of the exterior, which characterizes the development of the body and gives an idea of the size of animals. Better were animals of groups II.With the increase in the size of the udder-mass-metric index in cows, the level of assessments of the main descriptive traits is also significantly increased. The best indicators of the descriptive features of the linear classification of the exterior were the group of animals of the Ukrainian Black-and-White dairy breed, which, according to the value of the udder-maso-metric index, are classified as high-value groups of magnitude 16.9 or more. units, the worst – animals of the first group (11.7 and less than units of scientists). The difference between animals of the best and worst groups in 50% of cases was reliable (P < 0.05–0.001).The dynamics of dairy productivity in a certain way "copies" the dynamics of group and descriptive signs of the exterior type of animals. That is, with the increase of the size of the udder-mass-metric index there is a linear increase in quantitative characteristics of milk productivity.The animals of the group III showed the best results in PAC “Yerchyky”. From them received 305 days of the first lactation of 6036 kg with fat content of 3.63% and the amount of milk fat and protein, respectively, 218 and 185.0 kg. The lowest counts are first-born cows of group I (5390, 3.57, 193.5 and 166.3 respectively). Animals of group II occupy an intermediate position. The difference between the groups of animals for milk productivity, differentiated by the size of the exterior index in 40% of cases was reliable.The distribution of animals by the size of the extermination index (UMMI) completely copies their location according to the overall assessment of the exterior type and the 305 days lactation, which again confirms the existence of a direct correlation between these features. That is, differentiation and selection of animals by the size of the udder-mass-metric index can be an effective method for improving the milk production and exterivation of animals in the milk breed herd of PAC “Yarchiki”.With the help of the exterior index, we can predict milk productivity, that is, with the increase in the value of UMMI per unit milk productivity, namely, milk for 305 days of lactation, increases by 323 kg.Increasing the value of the udder-mass-metric index is accompanied by an increase in the consolidation factor for all the blocks of attributes. That is, the selection with the maximum value of the index of group III will help to increase the typification of animals by the exterior type and productivity.We also studied the influence of the exterior index on the manifestation of exterior and productivity. The results of this analysis showed that the share of this index in the overall variability of the signs varies within the range of 1.87–16.88 among the signs of the 100-score linear classification system and 0.31–7.92 among the signs of milk productivity, but it should be noted, that in 70 and 80% of cases the force of influence was reliable, respectively (P < 0,05–0,001). On average, the impact strength of the 9-point linear classification system was 2.94%.