Herd reproduction, cow milk producing ability and milk production efficiency when using sexed semen

Abstract

Herd reproduction, cow milk producing ability and milk production efficiency when using sexed semen are discussed. Semen from bulls of two lines, Reflection Sovereign and Vis Ideal, was used for insemination of heifers and cows. After calving, the cow reproductive organs were monitored for signs of cyclic ovarian activities. When necessary, hormonal and biologically active substances were administered to stimulate the estrous cycle or accelerate ovulation, and antibiotics were used to treat subclinical endometritis. The interval from calving to the first insemination was also regulated. Sexed semen was used on the farm for insemination of heifers since 2018, and for all animals since April 2024. The sex ratio shifted in favor of heifers: in 2018 it was 49.8/50.2, in 2020-2023 it changed to 63.8/36.2; in 2024 and 2025, the results achieved the goals recorded in similar investigations for sexed semen (at least 85% heifers) - 84.67/15.32 and 92.56/7.44, respectively. Over a three-year period, 3,797 heifers were inseminated; pregnancy after the first insemination was diagnosed in 2,275 (59.9%). The herd of dairy cows expanded rapidly with milk producing ability rising to 8,953 and 8,894 kg in 305 days of lactation for first-calf heifers and to 11,840 kg per cow per year with butterfat weight percentage of 4.45%. From 2022 through 2025, 151, 192, 309 and 400 heifers were sold, respectively. Annual milk production increased from 8,244 to 27,078 tons; milk marketability was 95.6% in 2018 and 96.2–96.5% in subsequent years. In 2018, 9,253 tons of milk were sold in net weight with revenue of 7368 thousand Byelorussian rubles, in 2025 - 32,193 tons and 44007 thousand Byelorussian rubles. The profitability of milk production in 2023–2025 amounted to 42, 44, and 48%.