Generational recurrence of the breeding value of breeding bulls of the Holstein breed of German selection.

Abstract

Holstein breeding bulls available in LLC "Ukrainian Genetic Company" in the amount of 26 heads were evaluated by two methods: 1st - genomic evaluation (It is that a large number of livestock of a certain sex group (more than 10 thousands heads) each breed is working on a genomic map of the size and location of nucleotides (chips, markers), which is compared with specific indicators of economically useful traits of these animals obtained by traditional methods) and the 2nd - method ZW (breeding value of bull obtained by traditional evaluation) his productivity of daughters). 8 breeding Holstein bulls have genomic evaluation and 18 Holsteins were evaluated according to the ZW method. Among the signs of dairy productivity, which were used to assess the breeding value of breeding bulls used: milk yield, fat and protein content in milk, the amount of milk fat and protein. Estimation of generational recurrence was performed using the formula for calculating rank correlation. The genomic assessment of bulls of both Holstein breeds in terms of milk yield, protein content and amount of milk protein was better than their parents (exaggeration in Black-and-White is 222 kg, 0,05%, 5 kg, and in Red-and-White - 306 kg, 0,1% and 17 kg, respectively). In terms of the amount of milk fat in Black-and-White bulls, the score was 5 kg lower than in parents, and in Red-and-White bulls it was 5 kg better. At the same time, the results of parents evaluation of the fat content in milk turned out to be 0.02% better than those of their sons. Breeding value of bulls of Black-and-White Holstein breed in terms of milk yield and fat content was better than their parents (exaggeration is 190 kg and 0.08%). According to such indicators as protein content and the amount of milk fat and protein in Black-and-White bulls compared to their parents, the breeding value decreased by 0.32% and 1 kg, respectively. With regard to the Red-and-White Holstein bulls, a slightly different picture is observed. Sons increase their breeding qualities compared to their parents in terms of milk yield, amount of milk fat and protein content by 209 kg, 6 kg and 0.06%, respectively, and the decrease in breeding value in them is in terms of fat content and amount of milk protein by 0.06% and 1 kg. If we compare the results of the assessment of breeding value obtained by different methods, it should be noted that in the genomic assessment of the difference between parents and sons is more significant in almost all respects in Red-and-White Holsteins. At the same time, the difference between the bulls evaluated by the ZW method is lower and only on qualitative grounds there is a significant difference, which is characteristic of animals of the Black-and-White Holstein breed. The generational recurrence of genomic estimates of the breeding value of breeding bulls of the Holstein breed in comparison with the ZW method is characterized by a wider range of values in terms of dairy productivity. Thus, in the genomic evaluation, the rank correlation (r_s) in the parent-son pairs fluctuates in the range of – 0.96… 0.98, and in the evaluation by the ZW method - in the range of 0.17… 0.94. It should also be noted that in genomic evaluation the best repeatability in all experimental parameters, except for fat content, was shown by Black-and-White Holstein bulls, and in the evaluation by the ZW method - breeders of Red-and-White Holstein breed.