Relationship and milk production from selected samples of cattle population crossed with Hwolstein breed

Abstract

The aim of present work was to analyse the relationship and milk production of cows – crosses of holstein breed in selected population. To evaluatetheir relationship and milk production, records of wholelife productions, certificates of origin of individual animals and its crosses up to the 3rd generation of ancestors. The evaluated set of animals were divided into three breeding types according to genetic shore of Holstein breed (H): H1 – 87.5 – 93.74 % of Holstein blood; H2 – 75.0 – 87.4 % of Holstein blood; H3 – 50.0 – 74.9 % of Holstein blood. The calculated coefficients of relationship and milk production per 305-day lactation were evaluated by statistical methods. Significance of differences in relationship and milk production of all breeding types of cows were tested by Student t-test. In group of sires was established the coefficient of relationship Rxy = 9.52 % resp. E(Rxy) = 1.61 %. The highest Rxy (10.81 %) value was found in the H3-type (with lowest portion of Holstein blood), while the lowest (8.47 %) value was recorded in the cows of breeding type H1 (with highest portion of Holstein blood). Milk production was found to be highest in the group of H2 (9668 kg milk with 3.31 % fats and 3.13 % proteins), but the difference was significant only in case of the cows of group H1.