Of nutrients in the first heifers of the holstein breeding group of different genealogies

   The paper presents the indicators of feed conversion from the new first-calving daughters of 14 bull producers of two lines of black and motley Holstein breed in the conditions of their breeding in a livestock complex. Groups of analogues were selected. The costs of dry matter, energy exchange, crude protein, physically effective neutral-detergent fiber (physis. NDC), sugar, starch, crude fat and concentrates per 1 kg of milk, milk fat and protein are calculated. In the first calves of the Reflection Sovering line, the production of 1 kg of milk was much less spent than in their peers from the Vis Back Aydial line of metabolic energy, dry matter, nutrients and concentrates. Maximum milk productivity was noted in the daughters of the bull Modifi, in whom the average daily yield (32.3 kg) and the content of milk fat and protein (2.41 kg) were significantly higher than the average on the farm. In the daughters of the bull Alta Depot, on the contrary, the average daily indicators of yield (28.0 kg), milk fat and protein (2.13 kg) were significantly lower. Conversion rates for the production of 1 kg of milk, as well as milk fat and protein, were significantly lower in the daughters of three bulls: Modifi, Aros from the Vis Back Aydial line and Kaminsky from the Reflection Sovering line. For the daughters of these bulls, the cost of concentrates per 1 kg of milk was 287-300 g and was significantly lower than the herd average. The low costs of concentrates per 1 kg of milk fat and protein (3.84 kg) differed only in the daughter of the bull Modifi. Higher costs of dry matter, exchange energy, nutrients were noted in the daughters of the Alta Depot bull from the Vis Back Aydial line. They also spent the maximum amount of concentrates per 1 kg of milk, milk fat and protein, respectively, 333 g and 4.37 kg. According to the results of our research, the best on the farm in terms of conversion exchange of energy, dry matter, nutrients and concentrates per 1 kg of milk, milk fat and protein were the daughters of the bulls Modifi, Aros from the Vis Back Aydial line and Kaminsky from the Reflection Sovering line.

1. Tokarev V.S. Kormlenie zhivotny`x s osnovami kormoproizvodstva: ucheb. posobie (Animal feeding with the basics of feed production), Moscow: INFRA-M, 2017, 592 p.

2. Kudrin M.R., Izhboldina S.N., Nikolaev V.A., Chukavin V.P., Izvestiya Gorskogo gosudarstvennogo agrarnogo universiteta, 2016, Vol., 53, No. 1, pp. 40–44. (In Russ.)

3. Anoxin S.M., Batalov E.B., Luczkix T.V. [i dr.], Razvitie biotexnologii: novaya real`nost` (Development of biotechnology: a new reality), Collection of the International Scientific Conference Novosibirsk, October 31, 2022, Novosibirsk: ICz NGAU “Zolotoj kolos”, 2022, pp. 19–27. (In Russ.)

4. Bel`kov G.I. Vestnik myasnogo skotovodstva, 2010, Vol. 3, No. 63, 108 p. (In Russ.)

5. Kudrin M.R., Izhboldina S.N., Nikolaev V.A., Chukavin V.P., Izvestiya Gorskogo gosudarstvennogo agrarnogo universiteta, 2016, Vol. 53, No. 1, pp. 40–44. (In Russ.)

6. Dostovalova L.G., Czopanova A.V., Razvitie nauchnoj, tvorcheskoj i innovacionnoj deyatel`nosti molodezhi (Development of scientific, creative and innovative activities of youth), Collection of the X All-Russian (National) Scientific and Practical Conference of young Scientists, dedicated to the 75<sup>th</sup> anniversary of the Kurgan State Agricultural Academy named after T.S. Maltseva, Kurgan, November 29, 2018, Kurgan: Kurganskaya gosudarstvennaya sel`skoxozyajstvennaya akademiya im. T.S. Mal`ceva, 2018, pp. 45–51. (In Russ.)

7. Kolchev A.G. Sibirskij vestnik sel`skoxozyajstvennoj nauki, 2018, Vol. 48, No. 2, pp. 49–54. (In Russ.)

8. Loretcz O.G., Gorelik O.V., Shmelev I.A., Molodezh` i nauka, 2015, No. 4, pp. 39–47. (In Russ.)

9. Privalo O.E., Shveczov N.N., Privalo K.I., Dostizheniya nauki i texniki APK, 2017, Vol. 31, No. 12, pp. 47–49. (In Russ.)

10. Andriyanova E`.M., Xaziaxmetov F.S., Vestnik BGAU, 2010, No. 3, pp. 8–11. (In Russ.)

11. Pustonina G.F. Izvestiya Orenburgskogo gosudarstvennogo agrarnogo universiteta, 2006, No. 2 (10), pp. 163–166. (In Russ.)

12. Ganushhenko O.F. Zhivotnovodstvo Rossii, 2020, No. 1, pp. 59–61. (In Russ.)

13. Popov V.V. Adaptivnoe kormoproizvodstvo, 2021, No. 1, pp. 65–80. (In Russ.)

14. Mironov N.A., Karamaev S.V. Selekcionny`e i texnologicheskie aspekty` intensifikacii proizvodstva produktov zhivotnovodstva (Breeding and technological aspects of intensifying the production of livestock products), Collection of Articles of the All-Russian Scientific and Practical Conference with International Participation, Dedicated to the 150^th Anniversary of the birth of Academician M.F. Ivanova. Moscow, March 03-04, 2022, Moscow: RosGAU – MSXA im. K.A. Timiryazeva, 2022, part 1, pp. 376–381. (In Russ.)

15. Panin V.A. Izvestiya Orenburgskogo gosudarstvennogo agrarnogo universiteta, 2018, No. 5 (73), pp. 221–224. (In Russ.)