TYPE TRAITS OF AYRSHIRE COWS IN DIFFERENT REGIONAL POPULATIONS AND THEIR RELATIONSHIP WITH MILK PRODUCTION

The main selection and genetic parameters of the linear and classification traits of the exterior of 1,438 first calving cows of the Leningrad, Kirov and Vologda regions of the Russian Federation. Most variable indicators were "udder cleft" in all three populations (30.65; 36.67; 30.47 %) and "body depth" in the Vologda and Leningrad populations - 35.57 and 23.40 %, respectively. The “rump width” in the Vologda population at Cv = 41.6% had a rather low absolute score (2.31 ± 0.08 points), therefore more careful selection is needed. The soft pasterns (26.8%), additional teats (26.2%), and slack back (8.3%) were the most common deficiencies. Less common were a peaked rump (6.2%), a high-set tail (4.8%), and a pterygoid scapula (4.1%). The construction of linear profiles of bulls Geyser, Lepa, Landskape using the standard transmission ability (STA) for each linear and classification types was carried out. The largest positive correlation values of the rear udder width (0.30, P≤0.001), front length udder (0.24, P≤0.001), body depth (0.12, P≤0.001) and dairy form (0, 10, P≤0,001). Reliability negative relationship between the corner rump and milk yield -0.09 (P≤0.001).