ВЗАИМОСВЯЗЬ УПИТАННОСТИ, МОЛОЧНОЙ ПРОДУКТИВНОСТИ И ВОСПРОИЗВОДИТЕЛЬНЫХ КАЧЕСТВ КОРОВ-ПЕРВОТЕЛОК

Abstract

The purpose of this study was to identify the relationship of the body condition score (BCS) of first-calving cows with different physiological condition before and after calving with milk production and reproductive performance. Evaluation of the BCS of Holsteinized black-and-white first-calving cows (n = 509) was carried out using a five-point scale with a step of 0.25 point two weeks before calving, in the first days after calving, during the period of maximum milk yielding, at the end of lactation, during the dry period. The first-calving cows were divided into groups in the period before calving with a BCS of 3.50, 3.75 and 4.00 points, in the period of the pick of milking with a BCS of 2.50, 2.75, 3.00, 3.25 and 3.50 points, loss of BCS - without loss of points, with a loss of 0.50, 0.75, 1.00 and higher points. As a result of the research, it was established that the first-calving cows, who had a BCS before calving, above the norm, were fed 305 and 100 lactation days less by 368 (p <0.05) and 288 (p <0.001) kg of milk and had a shorter service period (16 days at p <0.1) than animals with a BCS of 3.75 points. It was revealed that primary first-calving cows with BCS during the period of the pasture above the norm (3.50 points) were fed for 305 and 100 days of lactation by 1005 and 217 kg of milk less (p <0.01) than animals with a fatness of 2.50 points. In first-calving cows with a BCS in the maximum milk yield period of 3.50 points, the service period is shorter by 40 days with p <0.05 than in animals with a BCS of 2.75 points. It was established that with the loss of BCS during the maximum milk yield period of 0.75, 1.00 or more, primary first-calving cows have higher milk productivity for 305 and 100 days of lactation by 526 and 624 kg of milk and 185 and 201 kg of milk with p <0.05 than animals without loss. First-calving cows, who lost the most in BCS, have the largest service period (178 days) with a difference of 37 days with p <0.05 with a group of animals that had no losses. The phenotypic correlation between the BCS of the cows during the maximum milk yield period and milk productivity over 305 and 100 days and the service period revealed a negative reliable (-0.216, -0.193, -0.228). Thus, for stable reproduction in the herd, it is necessary to create conditions for feeding and housing, contributing to the maintenance of BCS up to calving at the level of 3.75 points, and in the pick of milking, to prevent its decline by more than 0.5 points.