О. I. Leshonok, I. V. Tkachenko
Ural Federal Agrarian Scientific Center, Ural branch, Russian Academy of Sciences, ul. Glavnaya, 21, pos. Istok, Ekaterinburg, 620061, Russian Federation
Abstract. The study aimed to compare the indicators of the breeding value of stud bulls by the constitution type of their daughters determined by the methods of genomic forecasting and actual assessment of the offspring’s quality. The work was performed in 2019 in the breeding organizations of the Sverdlovsk region. We studied the constitutional and conformation characteristics of 507 first-calf heifers of Black-and-White Holsteinized breed with the content of the blood of the Holstein breed of more than 87.5%. The cows were descendants of seven foreign stud bulls, six of which belonged to the Blackstar (five bulls) and Chief Mark (one bull) branches of the R. Sovereign line; one bull belonged to the Prelude branch of V. Aidial’s line. We compared the values of the indicators of the standard transmitting abilities (STA) of bulls calculated according to the data of genomic testing on the reference non-Russian populations and the actual linear assessment of the offspring on a 9-point scale. Values from -1 to +1 on the STA scale and from 4.8 to 5.3 on a 9-point scale were considered neutral. The proportion of conformation features was calculated as a percentage of the total number of features (18), in which the actual and predicted directions of development coincided. The smallest percentage of scores coincidence was 31.3%; the greatest percentage was 68.9%; the average percentage was 50.0%. The highest coincidence of STA indices and the actual conformation score was registered for the udder characteristics. We noted the coincidence of from 2 to 6 out of 7 characteristics. Opposite trends in genomic and actual scores were found in the stud bulls of the Blackstar branch. In this branch, we evaluated height at the sacrum, the strength of the loin, and expressiveness of milk forms. In stud bulls of other genealogical groups, the discrepancy was established in body depth, pelvis position, the width of the hind lobes of the udder, and heel height. To predict stud bulls’ breeding value scores more accurately, it is necessary to compile a Russian national reference base.
Keywords: Holsteinized Black-and-White cattle; stud bull; genomic assessment; standard transmitting capacity (STA); progeny assessment; body type; conformation.
Author Details: О. I. Leshonok, Cand. Sc. (Agr.), leading research fellow; I. V. Tkachenko, Cand. Sc. (Agr.), leading research fellow (е-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.).
For citation: Leshonok ОI, Tkachenko IV. [Predicted and actual influence of Holstein stud bulls on the conformation characteristics of their daughters]. Dostizheniya nauki i tekhniki APK. 2020;34(11):83-7. Russian. doi: 10.24411/0235-2451-2020-11112.