The relationship of productive longevity of cows and age of highest lactation in industrial technology

Purpose. The study of the relationship between the age of the highest productivity for lactation and the further duration of the period of economic use of cows. Materials and Methods. The work was carried out in the conditions of the dairy complex of LLC Agricultural Enterprise "Donskoye" in the Volgograd region. The object of the study is cows of Danish selection, uniform in date of birth, time of insemination and calving, which were culled from the herd in the period from 2016 to 2020. Statistical analysis of zootechnical and breeding records data and productive indicators of the animals participating in the experiment was carried out using the information and analytical system “SELEX – Dairy Cattle” (RC PLINOR LLC, Russia) and the Dairy Plan computer program (Germany). Results. The conducted studies established that the early age of peak lactation did not have a positive effect on increasing the period of productive and economic use of Holstein cows of Danish selection. It was also noted that a decrease in milk yield during lactation prolongs the period of economic use of animals and, accordingly, longer operation increases the lifetime productivity of cows. The highest milk yield for lactation in the amount of 10633.3 kg and the average milk yield for all lactations at the level of 9742.1 kg make it possible to obtain a lifetime milk yield of 34088.3 kg with a productive duration of 3.5 lactations. The productive potential of these animals, revealed during the second lactation, is 11,000.8 kg. Conclusion. The extension of the period of productive use to 3.5 lactations, that is, four calvings, for highly productive cows of Danish selection is possible with an average milk yield per lactation of 9742.1 kg, while the lifetime milk yield per cow will be 34000.0 kg of milk.