SELECTION OF HEREFORD STUD BULLS BASED ON PREDICTED PRODUCTIVITY ASSESSMENT BY THE BLUP METHOD

Abstract

The formation of a “model” group of Hereford stud bulls for bull-producing cows of the breeding core based on purebred breeding, taking into account the breeding value using the method of the best linear unbiased prediction – BLUP. In the APC “De Gusto” of the Republic of North Ossetia-Alania, progeny groups were formed from six bulls belonging to three genealogical lines. The stud bulls, Kras 2443 and Kumir 25115 (from Flipper 267 genealogical line), had the highest breeding value assessment (BVA) for average daily gain from 7 to 12 months (+72,6 and +47,0 g). Keton 2051 and Frukt 9001 (Favorita 21004 genealogical line) received a negative assessment – -28,9 and -42,1 g, Klyk 2029 and Karbon 2331 (Timelin 237W genealogical line) – -96,2 and -99,9 g. The average daily gain in live weight of the sons of the stud bulls Kras 2443 and Kumir 25115 of the Flipper 267 line was 1025,4 and 1005,2 g, the difference in their favor, compared to their herdmates – progeny of the stud bull Karbon 2331 of the Timelin 237W genealogical line, was 116,1 (P ˂ 0,05) and 95,9 g (P ˂ 0,01). The correlation coefficient between live weight at one year of age and average daily live weight gain from 7 to 12 months was high and amounted to r² = 0,69–0,94. The coefficient of variability of average daily gain was higher in the group of the stud bull Flipper 21004 and was within the range of 20,9–30,28%. In other groups, it was 9,76–13,18%. For reproduction in the bull-producing group of cows, stud bulls Kras 2443 and Kumir 25115 were selected with an assessment of breeding value for average daily gain of +72,6 and +47,0 g with an assessment significance of 92 and 89%, and an accuracy of 84 and 79%. The remaining bulls are not recommended for use in the breeding process based on this trait.