Features of Conformation Type of Cows Firstborn Ukrainian Black-and-White Dairy Cattle in Their Phenotypic Relationship With Milk Yield

Abstract

Evaluation of animals for breeding Ukrainian Black-and-White dairy breed was carried out according to the method of linear classification of type in the breeding farms of LLC "Vladana" and the experimental farm of the Institute of Agriculture of the North-East of the NAAS (EF IANE). The estimation of cows in the herd of BF "Vladana" (83.8 score) on this set of milk-type traits in comparison with peers of the EF IANE (82.3 score) showed a significant advantage of the former with a highly reliable difference of 1.5 score (P <0.001). The average estimate at the level of 84.2 and 83.0 score in cows of the herd of SF "Vladana" and NAAS EF IANE indicated about fairly good development of their body. The best condition of limbs in animals of the herd BF "Vladana" with 83.5 score and slightly worse than in peers EF IANE (82.5 score) with a highly significant difference of 1.0 score (P <0.001) in favor of the former. Udder in animals of the breeding farm "Vladana" with an average grade of 84.7 score was on the 2.3 score higher (P <0.001) compared with peers in the EF IANE (82.4 score). In general, firstborn cows of controlled farms in the BF "Vladana" and EF IANE, which were classified according to the final type assessment, received an average score of 84.2 and 82.8 of 88 possible for animals of this age, which corresponded to the level on the international scale "Good Plus". The results of the estimation of first-born cows in the controlled farms show that the degree of the main descriptive traits development of conformation, provided by the method of linear classification, differed by significant intra-herd and inter-herd variability. A sufficient level of reliable positive relationship with milk yield was found both by group traits, except for limbs, and by the vast majority of descriptive traits of the conformation, with slightly higher correlation coefficients in cows of BF "Vladana". The determined phenotypic correlations between linear conformation traits and milk yield per lactation indicate about their reliability in the selection of cows by productivity.