THE INFLUENCE OF THE OF BREEDING VALUE SIZE OF HOLSTEIN BULLS ON THE GAIN OF LIVE WEIGHT
The work purpose was to determine genomic breeding value and the influence of its size on gain of live mass of the bulls of Holstein breed received and grown up to one-year age in climatic conditions of Holland (22 heads) and Canada (5 heads) then grown in the conditions of Central Siberia on Krasnoyarsk pedigree farm up to 2 years of age. The tasks were to determine genomic breeding value of controlled bulls during the age period of 12-24 months, to give the analysis of live weight at 12, 18 and 24 months, the growth rate of live weight during age periods of 12-18, 18-24 and 12-24 months, to establish the influence of the size of genomic breeding value of the bulls on live weight at 24-months of age, on the growth rate of live weight in absolute and relative val- ues during the age period of 12-24 months by comparison of the size of the difference of these indicators in each bull, the average size of all genotyped bulls and indicators of genomic breeding value of each bull. Manufacturing bulls of Holstein breed were the object of the researches. It was established that for the age period from 12 to 24 months from the deliv- ered 27 bulls 9 (33.3 %) were not accepted generally on the indicators of quality of spermoproduction, in this connection 22 were genotyped and participated in pilot studies of 18 bulls which genomic breeding value on average made 1837 units and fluctuated from 1601 to 2247 with the difference in 646 units (35.2 %). In genotyped bulls at identical conditions of keeping and feeding live weight at 24-months age averaged 687 kg and fluctuated from 617 to 755 kg, with the difference to average group size from-70 kg (10.2 %) to +68 kg (9.9 %), the growth rate of live weight during 12-24 months in abso- lute values averaged 776 g and fluctuated from 704 to 945 g with the difference to average group size from-72 g (9.3 %) to+169 g (21.8 %), in the relative sizes of 51.3 %, 44.1-59.2 % and from-7.2 % to +7.9 % respectively. The bulls estimated genomically with GPTA size have more or less average group size, in 24 months and growth rates of live weight in absolute and relative values during the age period of 12-24 months approximately equally found the indicators of sizes of these signs in indicators of the difference of the bull and group on live weight more or less average group that convincingly says that the size GPTA of the bull does not influence the indica- tors of the gain of live weight, and specific features of bulls. The results received in scientific researches allowed to select 9 best bulls for using in reproduction in the herds of red and motley breed, the Yenisei type of red and motley breed, black and motley breed and Krasnoyarsk type of black and motley breed of cattle, and also to use them for the development of recommendations about using the methods of genomic selec- tion for the assessment of reproductive qualities of bulls at early age.