Milk productivity and reproductive ability of ukrainian black-spotted dairy breed cows of different type of constitution

Abstract

The analysis was done on milk production and the reproductive ability of cows of Ukrainian Black-Spotted dairy breed cows of different types of constitution under conditions of breeding farm «Yamnytsya» Tysmenytsya district, Ivano-Frankivsk region. Determining the type of constitution of animals was carried out by mass-metric coefficient, indicator of which were differentiated from its deviation from the arithmetic mean share at 0.43 of sigma (σ), three types of constitution: tight, intermediate and loose. It is established that the milk yield and reproducible ability of cows depended on the type of constitution. For the first, second, third and better lactation the highest milk yield and the amount of milk fat were observed cows of dense type of constitution, and what prevailed animals of intermediate and loose types in 428.0–1318.2 and 11.9–49.2 kg respectively. The largest share of influence of the type constitution on yield and the amount of butterfat in the first lactation (18.51 and 18.42%) and on the fat content in milk for the second and third lactation (10.98 and 17.11%). The correlation coefficients between the type of constitution and milk yield, depending on lactation, were in the range 0.047–0.410, fat content in milk – -0.098– -0.423 and the number of milk fat – -0.032– +0.403. The highest connection between the type of constitution and milk yield milk yield and quantity of milk fat were observed in the first lactation, and in the second, the third and best lactation – between the type of constitution and fat content in milk. Lower age of first calving cows were characterized cows of dense type of constitution, which conceded intermediate and loose type. For the duration of service- and between calving period, the coefficient of reproductive capacity, calves output per 100 cows, index of heifers insemination and firstborn cows, animals of dense type constitution conceded the intermediate and loose types. High and reliable (P < 0.01–0.001) influence of constitution type had on the duration and service-and between-calving period, the coefficient of reproductive capacity, calves output per 100 cows, and index of heifers insemination – within 6.03–7.09%, and the smallest - on the duration of gestation of heifers and firstborn cows – 0.66 and 0.41% respectively. The highest positive and highly probable correlation coefficients were observed between the type of constitution of animals and the duration of their service- and between calving period (0.283 and 0.278) and negative, but probable links – between the type of constitution and coefficient of reproductive capacity (-0.271) and calves output per 100 cows (-0.269). Available communication indicates the possibility and expediency of dairy cattle breeding by mass-metric coefficient, that will promote simultaneous enhancement of their milk production at selection by external-constitutional type.