The interconnection between the first calving age and milk yeild of the dairy red cattle

Purpose: A regression analysis was used to study the relationship between age at first calving and lactation duration with first-lactation milk production indicators for subsequent consideration in breeding index modeling.

Materials and Methods. The study was conducted using the SELEX-Dairy Cattle information database from 18 breeding farms breeding dairy red cattle. Over 12 000 records of cows that comleted their first five lactutions from 2018 to 2023 were analised. The relationship between the characteristics was determined by calculating the regression coefficient in programm "Statistica". After determining whether the sample conformed to the normal distribution, milk production data from 10,284 cows were used in the calculation. The average milk yield of first-calving cows in the sample was 5,683 kg, with a fat content of 4,13 % and a protein content of 3,26 %. The first calving age in the sample group was an average of 32,2 month. The average lactation duration for cows that completed their first lactation was 359 days.

Results. The study showed that the age increase of the first cows calving age impacted negatively on milk yield over 305 days lactation period, reducing it by 25,4 kg per month based on average observations during 5 years. A decrease in milk fat yield by an average of 2,0 kg and milk protein yield by 0,3 kg was observed. The age of the first cows calving showed the most significant impact on cows dairy productivity, that completed their first lactation in year 2022: with a one-month increase in age at first calving, milk yield decreased by 110 kg over 305 days lactation period, milk fat yield by 6,6 kg, and milk protein yield by 3,4 kg. The age of the first calving of cows, that were under our examination, was more than 26 months, which significantly increases raising costs.

1. Sivkin N. V. Reproduction and productivity of the formed herds of Ayrshire, Simmental and Black-and-White cattle breeds / N. V. Sivkin, N. I. Strekozov // Zootechnics. – 2021. – № 12. – P. 14—19.

2. Tatueva O. V. The influence of Holsteinization on the productive longevity of Black-and-White cows in the Smolensk region / O. V. Tatueva, D. N. Koltsov // Russian Agricultural Science. – 2023. – № 4. – P. 56—61.

3. Rudenko O. V. The influence of Holstein blood on productive longevity and lifetime milk productivity of black-and-white cows / O. V. Rudenko, S. P. Eremin // Bulletin of the Ulyanovsk State Agricultural Academy. – 2015. – № 2 (30). – P. 132—136.

4. Knyazeva T. A. The influence of Holstein bloodline on the reproductive function of Red Steppe cows and heifers / T. A. Knyazeva, T. A. Moroz, et al. // Proceedings of the XXVII Int. scientific and practical. conference "Improving the competitiveness of animal husbandry and the tasks of personnel provision". – Podolsk, 2021. – P. 68–75.

5. Knyazeva T. A. Reproductive qualities of cows and heifers of red dairy breeds in farms of the Russian Federation / T. A. Knyazeva, T. A. Moroz, E. A. Matveeva // Proceedings of the XXVI Int. scientific and practical. conference "Improving the competitiveness of animal husbandry and the tasks of personnel provision". – Podolsk, July 7, 2020. – P. 229–235.

6. Shevchuk A. P. Preservation of the gene pool of the red steppe breed / A. P. Shevchuk // Young researchers of the agro-industrial and forestry complexes – to the regions: Collection of scientific papers based on the results of the VIII All-Russian scientific and practical conference with international participation, Vologda-Molochnoye, April 20, 2023. Volume 3. – Vologda-Molochnoye: Vologda State Dairy Farming Academy named after N. V. Vereshchagin, 2023. – P. 158—162.

7. Valitov H. Z. Technological qualities of milk of cows of the red steppe and black-and-white breeds / H. Z. Valitov, V. A. Kornilova, A. I. Frolkin // Innovative achievements of science and technology in the agro-industrial complex: Collection of scientific papers of the Int. scientific and practical conference, Samara, December 18, 2018. – Samara: Samara State Agricultural Academy, 2018. – P. 22—25.

8. Naryshkina E. N. Milk productivity of Red Gorbatovskaya cows of different genotypes / E. N. Naryshkina, A. A. Sermyagin [et al.] // Proceedings of the Kuban State Agrarian University. – 2024. – № 116. – P. 298—306.

9. Panfilova G. I. Some selection and genetic parameters and the relationship between productivity traits of purebred and crossbred first-calf cows / G. I. Panfilova, I. V. Zasemchuk, O. L. Tretyakova // Bulletin of the Orenburg State Agrarian University. – 2021. – № 1 (87). – P. 284—287.

10. Kahikalo V. G. The influence of the age of first calving of black-and-white cows on milk productivity indicators / V. G. Kahikalo, O. V. Nazarchenko, L. A. Shabunin, N. A. Shabunina // Chief Livestock Specialist. – 2015 – № 5–6. – P. 11—15.

11. Jamrozik J. Genetic evaluation of dairy cattle using test day yields and random regression model / J. Jamrozik, L. R. Schaeffer, J. C. Dekkers // J. Dairy Sci. – 1997. – № 80(6). – P. 1217—1226. doi: 10.3168/jds.S0022-0302(97)76050-8.

12. Committee on Agriculture 29 Session Proposal for an International Day of Milk / Committee on Agriculture 29 Session [Электронный ресурс] // FAO: [сайт]. — URL: https://openknowledge.fao.org

13. /server/api/core/bitstreams/af3c92a6-7b32-4f8f-8cc6-7ce3b7a5fc17/content ( 17.04.2025).

14. Wathes D. C. Heifer fertility and carry over consequences for life time production in dairy and beef cattle / D. C. Wathes, G. E. Pollott, K. F. Johnson, H. Richardson, J. S. Cooke // Animal. – 2014. – Suppl 1. – P. 91—104. doi: 10.1017/S1751731114000755. PMID: 24698359.

15. Yearbook on breeding work in dairy cattle breeding in farms of the Russian Federation (2024). - M: VNIIPlem. — 2025.