Control system of reproductive functions in highly productive Holstein cows

Abstract

The effectiveness of reproductive function control in Holstein cows using sexed semen was studied. Cows were inseminated not earlier than 78 days after calving. Hypophysin (rutocin), Ultracef, Gisterosan MC-2, and vitamin supplements were used to treat animals with reproductive disorders. In cases of endometritis, treatment was limited to a single, or in lesser cases, two or three or more, intrauterine injections of Gisterosan MC-2. If cows were not in heat, they were examined, and if ovarian follicles were detected, they were injected with 5 mL of Surfagon (2.5 mL of Fertagyl). Gisterosan MC-2 was administered if indicated; if cows were not in heat for ≥ 10 days, the examination was repeated, and if a corpus luteum was present, a Prostaglandin was injected. If estrus or a dominant follicle (9-15 mm) was detected during the examination, 5 mL of Surfagon was injected and insemination was performed. Surfagon and Prostaglandin were used in cases of ovarian cystic disease and ovarian hypofunction. In six month groups of cows (1232 and 923 animals), the interval from calving to the first insemination was (99.6 ± 21.8) and (95.0 ± 20.3) days, and to fertilization - (132.1 ± 37.7) and (134.1 ± 37.7) days. Delayed insemination was significantly associated with ovarian dysfunction. The incidence of anestrus was 23.5%, ovarian cysts - 0.97%, and combined disorders - 5.2%. Extending the interval to the first insemination did not result in any improvement in conception. The best result was observed in cows inseminated not later than 85 days (65.4%), with a service period of 97.2 ± 1.8 days. Across the herd, 1,919 calves were born that year, including 70 (3.65%) stillborn, and 1,579 (85.4%) of the 1,849 live calves were females. The factors contributing to decreased reproductive performance include delayed first insemination, ovarian dysfunction, inflammatory processes in the reproductive organs, and lower conception rates when using sexed semen.