The evaluation of productive traits of Yaroslavl breed cows

The article presents an assessment of the productive characteristics of the Yaroslavl breed cows on a breeding farm. The object of the study was 107 Yaroslavl breed cows. When assessing the productive characteristics, it was found that the milk yield of purebred cows to the 3rd lactation significantly increased by 1095.5 kg of milk or 20.8% (P≥0.999) and amounts to 6357 kg of milk. Full-grown cows significantly exceed first-calf cows in live weight - by 64.2 kg or 14% (P≥0.999). The most highly productive are cows belonging to the Dobry line. The milk yield of this group of cows exceeds the average values of the sample for the first lactation by 341 kg of milk or 6.5%, for the third lactation - reliably by 1170 kg of milk or 18.4% (P≥0.95), respectively. Cows of the Marta line have more milk fat and milk protein, while the milk fat content increases by full-term lactation by 0.33% and is 4.91%, which is reliably higher than the average values of the entire sample of purebred cows by 0.55% (P≥0.999). A positive correlation is observed between the age at first calving and such indicators as milk yield in the first lactation (r = 0.24), live weight in the first and third lactations (r = 0.17, r = 0.14), as well as between milk fat content and milk protein content in the first and third lactations (r = 0.41, r = 0.50). Thus, among purebred Yaroslavl cows, it is recommended to select according to milk yield and milk protein content, which positively correlate with live weight and milk fat content. Taking into account the economic justification, when selecting Yaroslavl cows, it is necessary to give preference to bulls of the Dobry and Mart lines, since the daughters of such bulls have high productivity indicators.