Productivity of Holstein heifers and fi rst-calf cows of different paternal origin

Abstract

The origin of an animal determines its productive and breeding traits. It is well known that in dairy cattle breeding a great importance belongs to sires, especially those belonging to the leading lines of Holstein breed. The productive indicators of heifers and fi rst-calf cows the off spring of diff erent lines of Holstein breed and daughters of diff erent sires have been presented in the article. The researches have been carried out under the environments of specialized enterprises for rearing of replacement heifers and milk production. Diff erences have been found in the daughters of diff erent sires in terms of live weight and milk productivity. Accounting for the weight growth of the daughters of sires has shown that the live weight of heifers between the lines Wes Ideal 933122 and Refl ection Sovereign 198998 was not a signifi cant diff erence. Daughters of sire # 511H11283 of the line Refl ection Sovereign 198998 in all age periods had a live weight, absolute and average daily gain, the growth rate of replacement heifers was higher than the daughters of other sires. At one year of age, their live weight was higher than that of heifers-daughters of sires # 11H11596, # 11H11565 and # 511H11422, respectively, by 4,1 % (P<0,001), 3,1 % (P<0,01) and 5,0 % (P<0,001). The daughters of sire # 511H11283 of Refl ection Sovereign line also had a higher yield of calves – 104,8 %. However, the largest number of heifers (75,7 %) has been obtained from the daughters of sire # 11H11565 of Refl ection Sovereign line. In terms of milk yield, signifi cant diff erences have been found between the lines and daughters of diff erent sires. Higher milk yield was obtained from the fi rst-calf cows of line Wes Ideal 933122 (12361±321 kg) and the daughters of the sire Mogul 11H011757 (13587±328 kg). According to the mass fraction of fat and protein in milk, the duration of the period of open days and the number of inseminations, there were no signifi cant diff erences between the studied groups of animals. Thus, the infl uence of specifi c sires on individual productive indicators of daughters has been established.