Realization of the potential of cows of Holstein breed of different generations in terms of productive traits

Abstract

Breeding work with dairy cattle in the Kurgan region is aimed at breeding animals that combine the adaptive properties and valuable traits of cattle of Black-and-White breed with a high proportion of genes of Holstein breed. Such animals are characterized by high productivity and suitability for intensive technology of their housing. The purpose of the research was to determine the indicators of milk productivity of first-calf heifers of different generations of Holstein breed, imported to the pedigree farms of the Kurgan region, as well as to determine the degree of realization of the genetic potential of animals. Scientific research has been carried out in the herd of CJSC “Glinka” (Kurgan), where highly productive cattle of Black-and-White and Holstein breeds are bred. The subject of research was the first-calf heifers of the imported Holstein breed of German selection of different generations, as well as the herdmates of Black-and-White breed. It has been found that the realization of the genetic potential for milk yield in Holstein cows of German breeding was higher and amounted to 76,4 %, in cows of Black-and-White breed 69,9 %. The highest milk yield for 305 days of lactation has been observed in the second generation of Holstein heifers 8905 kg, which exceeded the milk yield of herdmates of the second and third generations by 113 kg or 1,26 % and 174 kg or 1,95 %, respectively. The mass fraction of fat in German Holsteins of different generations ranged from 3,99 to 4,21 % (P < 0,001), while the mass fraction of protein in the milk of first-calf heifers varied slightly in the range from 3,18 to 3,20 %. In terms of live weight, the animals of the third generation slightly exceeded the herdmates of the 1st and 2nd generations by 19 kg or 3,25 % and 20 kg or 3,43 %, respectively. The largest profit has been received from the first-generation first-calf heifers of Holstein breed of German selection, where the level of profitability of milk production was 50,7 %, which was higher than that of the herdmates of the second and third generations by 3,9 and 7,9 %, respectively.