PHENOTYPIC CONSOLIDATION DAUGHTERS OF BULL-SIRES ESTIMATED BY THE METHOD OF LINEAR CLASSIFICA-TION
Authors: Khmelnychyi Leontiy , Khmelnychyi Serhii , Bardash Dmitryi 
Published: June 2021

The aim of our research was to determine the degree of phenotypic consolidation coefficients of bull-sires daughters in the Sumy intra-breed type of Ukrainian Black-and-White dairy breed, estimated by linear traits that characterize the conformation type of cows. The experimental base of research was information on the linear classification of first-calf cows of Sumy intra-breed type of Ukrainian Black-and-White dairy breed in the PE "Burynske" breeding farm in Pidlisnivskyi department of Sumy district. The estimation of the first-calf cows by type was carried out using the method of linear classification by two systems: 9-point, with a linear description of 18 conformation traits and 100-point including four complexes of breeding traits that characterize: dairy type, body, limbs and udder. The coefficients of phenotypic consolidation (K1 and K2) cows of selection groups for linear traits of the conformation were determined according to formulas proposed by Yu. P. Polupan (2005). The level of phenotypic consolidation daughters of bull-sires estimated by group conformation traits indicated that regardless of the origin, phenotypic consolidation coefficients by overall type assessment had a positive value with a wide variability of coefficient K1 from 0.056 to 0.512 and coefficient K2 – from 0.065 to 0.505. Among all estimated by phenotypic consolidation bulls, less consolidated by group linear traits were found sires of Ukrainian Black-and-White dairy breed – Motuzok and Front. Among sires of Holstein breed the best by group traits and overall assessment of the type were: V. Delight (K1 = 0.242-0.334; K2 = 0.247-0.349); D. Capris (K1 = 0.085-0.341; K2 = 0.089-0.348) and Hayes (K1 = 0.071-0.375; K2 = 0.082-0.370). From the sires of Ukrainian Black-and-White dairy breed the Iceberg was the best (К1 = 0.059-0.478; К2 = 0.047-0.472). Magnitude of the degree phenotypic consolidation of descriptive traits of linear estimation daughters of bull-sires, regardless of origin, differed significantly by higher variability in comparison with group traits. Coefficients of phenotypic consolidation calculated by the formula K1, varied according to the bull-sires assessment from -0.434 (teats length of Iceberg daughters) to 0.504 (rump angle of Milliam daughters). The higher variability of phenotypic consolidation coefficients was revealed according to the formula K2, whose level varied from -0.571 (udder depth of Lyubimy's daughters) to 0.546 (angularity of Milliam daughters). By the coefficients of phenotypic consolidation of descriptive traits K1 and K2, there wasn't found no one bull-sire only with positive values. The most consolidated for overwhelming majority of descriptive traits were the bulls-sires of Holstein breed – Lauer, Toprate and Milliam. The highest consolidation of descriptive traits had all daughters of bulls by angularity with the highest number of positive values of coefficients. The presence of a genetic influence of bull-sires on the degree of phenotypic consolidation of the majority of linear traits of daughters with a significant advantage of Holstein producers was established.