PHENOTYPIC CONSOLIDATION OF BROWN BREEDS COWS BY LINEAR TRAITS OF CONFORMATION TYPE
Authors: Khmelnychyi L. M. , Vechorka V. V. 
Published: June 2020

Breeding practice testifies that phenotypic and genetic specificity and an appropriate level of consolidation by leading economically useful traits are important characteristics and binding conditions for testing and subsequent genetic progress of breeds and their structural breeding units. Therefore, in the aspect of estimation of the conformation type of brown breeds in Sumy region – Lebedyn, Ukrainian brown dairy and brown Swiss, the level of phenotypic consolidation coefficients of firstborn cows, evaluated by the method of linear classification, was studied. Five farms of Sumy region were used as the basis of experiments: PJSC “Plemzavod “Mykhailivka” Lebedynsky, PAF “Kolos” and SE “Pobeda” of Bilopilsky and pedigree reproducers – AJSCCT “Zorya” Okhtyrsky and JSC “Mayak” of Trostyanets districts. The coefficients of phenotypic consolidation (K1 and K2) of breeding groups of animals on linear traits of conformation were determined by formulas proposed by Yu. P. Polupan (2005). Taking into account the importance of estimation of breeds of dairy cattle created in the process of interbreed combinations, in the aspect of studying the genetic progress and the desired level of their phenotypic consolidation, determining the degree of coefficients of phenotypic consolidation of cows of brown breeds in Sumy region by linear traits, that characterize the conformation type of animals, is motivated and relevant research. According to the group traits of 100-point linear classification system was revealed that the most consolidated by type were animals of brown Swiss breed by all group traits (K1 = 0.274–0.362; K2 = 0.262–0.369) and the final type assessment (K1 = 0.304; K2 = 0.322). The negative values of phenotypic consolidation coefficients indicated that the least consolidated by type were animals of the Swiss breed, especially on the group traits that characterize the dairy type (K1 = -0.012; K2 = -0.021), udder (K1 = -0.212; K2 = -0.231) and the final score (K1 = -0.028; K2 = -0.023). Animals of Ukrainian brown dairy breed were closer to the peers of brown Swiss cattle by both group traits (K1 = 0.202; K2 = 0.268) and by the final score (K1 = 0.219; K2 = 0.279). The consolidation coefficients of brown Swiss cows by group traits are (K1 = 0.274; K2 = 0.362), and by the final estimate (K1 = 0.304; K2 = 0.322). In a comparative analysis of the level of phenotypic consolidation coefficients of descriptive traits of the type was determined that of the evaluated breeds significant advantage by the phenotypic consolidation of these traits have animals of brown Swiss breed. The most consolidated firstborn cows of this breed for important descriptive traits of angularity (K1 = 0.362; K2 = 0.375), rear width (K1 = 0.293; K2 = 0.306, attachment of front (K1 = 0.289; K2 = 0.309) and rear ( K1 = 0.225; K2 = 0.229) udder parts, central ligament expression (K1 = 0.333; K2 = 0.371), udder depth (K1 = 0.296; K2 = 0.312), placement (K1 = 0.286; K2 = 0.303) and teats length (K1 = 0.321; K2 = 0.313) and locomotion (K1 = 0.304; K2 = 0.333). The determined hereditary influence of breed on the degree of phenotypic consolidation of the majority of linear traits testifies to the possibility of effective breeding of dairy cattle by type with intensive use of purebred sires of brown Swiss breed with high score by the linear classification of type of their daughters.