GENETIC CAUSES OF BIRTH OF IMPAIRED CALVES AND REPRODUCTION DYSFUNCTION OF A DAIRY HERD
Modern genotypes of dairy cattle created on the base of the Holstein breed are characterized by improved external conformation performance relatively to the milk-type expression of an animal and increased in comparison to the first mother rocks, by 25-50% by the milk production parameters, annual yield of the best cows in commodity farms can often reach 7500-9000 kg of milk. However, the uncontrolled use of bulls-improvers can often lead to disruption of the process of reproduction of the herd and the birth of weakened and unviable calves.
Analysis of the causes of the disturbance of the normal reproduction process in the dairy herd of black and white cattle, created by absorbing crossing with the Holstein bulls, showed that the cause of the birth of a weakened youngster with signs of deformity (internal organ dystopia, aplasia and hypoplasia of limbs, absence of lumbar vertebrae, eye pathology, atresia of anal verge) and clinical signs of a disturbance of the function of the gastrointestinal tract (diarrhea, refusal of feed, lethargy, oppression), dehydration (dryness and loss of skin elasticity, retraction of an eyeball), thickening of the joints was the use of the selection of parental pairs of seed bull with a genetic anomaly HH1C. In this case, the genetic analysis of the brood stock according to 12 types of haplotypes, associated with impaired fertility, and to 31 types of monogenic diseases showed that the reason of the birth of impaired calves was connected with genetic anomalies CVM and BLAD only for 6.9% of the breeding stock.
The research was carried out with the financial support of the Ministry of Education and Science of Russia under the Agreement No. 14.613.21.0081 with the Ministry of Education and Science of Russia from November 22, 2017, the unique identifier: RFMEFI61317X0081.