RELATIONSHIP OF THE CULLING OF FIRST-BORN COWS FROM THE HEARD WITH THE SCORE OF LINEAR TYPE TRAITS UNDER VARIOUS HOUSING

The results obtained in breeding plants indicate the influence of the technology of housing primiparous cows on their score of linear type traits. The influence of this factor ranged from 0.4% (p<0.01) to 2.9% (p<0.001). It was found that when stall housing, animals with a high assessment of body depth, angularity, and rear legs had a lower percentage of abandonment from the herd compared to animals with an average and low assessment of these traits (p<0.05). The results obtained when determining the percentage of abandonment of cows with different score of fore udder attachment indicate a greater staybility of first-born cows with a high assessment of this trait, which was 7.5-11% higher compared to animals with a lower score. The assessment of the central ligament of the udder (1.3%; p<0.05) and the depth of the udder (1.3%; p<0.05) had a probable impact on the abandonment of first-born cows from the herd. The number of animals that left the herd during the study period with a low assessment of the central udder ligament was higher by 0.7-13% compared to animals with a high and average assessment. A similar relationship between the loss of animals was established with the assessment of the depth of the udder (by 8.8-17.1%). The culling of first-born cows depending on the assessment of body structure traits in free housing, according to our data, probably depended only on one factor – the slope of the sacrum. The strength of the impact of the assessment of this trait was 2.9%. It is important to note that the percentage of animals leaving the herd with an average assessment of the slope of the sacrum was the lowest. When comparing the trends in the influence of the body structure traits of first-born cows on the level of their loss from herds under different methods of maintenance, it was found that, unlike tied housing, under free housing, there was a tendency to increase the percentage of culling first-born cows with a high growth assessment. Also, cows with a wide chest and a deep body had the highest risk of culling compared to the group of animals with average linear score indicators. There was a slight decrease in the percentage of culling of first-born cows with an increase in the score for the dairy type in both housing methods, animals with the desired posture of the hind limbs and a high score of the central ligament of the udder and body condition.