A. L. Aminova, N. G. Fenchenko, N. I. Khairullina
Bashkiria Research Agricultural Institute, Ufa Federal Research Center, RAS, ul. R. Zorge, 19, Ufa, Respublika Bashkortostan, 450059, Russian Federation
Abstract. In breeding, it is of great importance to obtain high-quality offspring from high-class stud bulls of promising lines. The purpose of the work was to study the growth and formation of the sexual cycle of heifers of Black-and-White breed to select the most promising individuals for breeding. Experimental studies were conducted on Black-and-White heifers in 2018–2019 in the Republic of Bashkortostan. Two groups of 20 heifers each were formed by the analogue method. The first group was formed from the animals produced from the stud bull Valun 1771; in the second group, it was animals produced from the stud bull Duplet 10101. In the heifers the growth rate was determined and the process of sexual cycle formation was evaluated. The daughters of Duplet 10101 bull were characterized by the highest indicators of live weight in the dairy period of growing up to the age of 6 months; the difference with the first group of 0.6–6.2 kg (0.56–4.42%) was insignificant. At the age of 6 months, slight superiority was noted in heifers from the first group; the difference with peers was 0.8 kg. We noted the tendency to superiority in live weight among the daughters of Duplet 10101 stud bull in the post-dairy period of growing at the age of 7–12 months. Their advantage over their peers was 2.2–6.9 kg (0.96–2.24%). During the growing period from the 12th to the 16th month, the live weight of the experimental animals from the second group was significantly higher than that of their peers by 8.2–21.9 kg (2.45–6.30%). High average daily gains contributed to the formation of the optimal live weight of all the heifers at the age of 18 months at the level of 438.2–443.5 kg. Mass and volume of the ovaries increased sharply at the age from the 5th month to the 10th month. The mass of the ovaries could reach (2.6 ± 0.005) g approximately by the age of one year, the growth rate and increase in weight slowed down a little, and then stabilized up to breeding age.
Keywords: heifers; breed; live weight; daily average gain; ovaries; sexual function.
Author Details: A. L. Aminova, Cand. Sc. (Biol.), senior research fellow (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.); N. G. Fenchenko, D. Sc. (Agr.), chief research fellow; N. I. Khairullina, D. Sc. (Biol.), leading research fellow.
For citation: Aminova A. L., Fenchenko N. G., Khairullina N. I. Features of the Growth and Formation of the Sexual Cycle of Heifers of Black-and-White Breed. Dostizheniya nauki i tekhniki APK. 2019. Vol. 33. No. 9. Pp. 54–56 (in Russ.). DOI: 10.24411/0235-2451-2019-10911.