PHENOTYPIC CONSOLIDATION OF GENEALOGICAL FORMS OF THE SUMSKY INNER TYPE OF UKRAINIAN BLACK-AND-WHITE DAIRY BARK BASED ON THE EVIDENCE OF THE LINEAR ESTIMATION OF THE EXTERIORS
Authors: Hmelnychyi L. M. , Hmelnychyi S. L. , Loboda A. V. , Klуmenko O. I. 
Published: December 2019

Taking into account the importance of evaluation of structural breeding units of created breeds and types of dairy cattle, in the aspect of studying the genetic progress and the desired level of their phenotypic consolidation, the study was carried out to determine the coefficients of phenotypic consolidation of the leading genealogical formations of Sumy intrabreed type of Ukrainian Black-and-White dairy breed by linear traits that characterize the conformation type of animals.

In studying of phenotypic consolidation of first-calf cows of different genealogical formations in the experimental group included the offspring of sires lines Valiant 1650414, Starbuck 352790 and Matt 1392858. Breeding groups, depending on the conditional part of heredity improving breed were as follows: I – 62.5–74.9; II – 75.0–87.4; III – 87.5 and >.

According to the 100-point system of linear classification, which includes the assessment four groups of body structure traits characterizing dairy type, body development, condition of legs and morphological qualities of the udder, for some of them, depending on the estimated line, observed a desired direction of phenotypic consolidation within the progeny of genealogical formations and evaluated conformation complexes.

At the same time, the interlinear differentiation was found on the indicators of consolidation coefficients when comparing conformation complexes. Regardless of the line's representation, a sufficient degree of phenotypic consolidation in the first-calf cows was revealed after a set of traits characterizing dairy type with variability of coefficients – 0.130–0.253 (K1) and 0.125–0.261 (K2), udder morphological qualities – 0.064–207 (K1) and 0.067–213 (K2); a final score of type 0.104–228 (K1) and 0.101–0.234 (K2). Higher coefficients of the phenotypic consolidation of the Valiant's offspring line indicate about their respective level of consolidation by group type traits.

The offspring of Matt's line by the level of consolidation coefficients significantly inferior to peers of the Valiant and Starbuck lines.

Unconsolidated by conformation type can include the number of animals with conditional heredity Holstein breed 62.5–74.9%. The vast majority of phenotypic consolidation coefficients of estimated traits in this group have been obtained with a negative sign, and if positive then the low level. Cows with a conditional blood of Holstein breed at the level of 75.0–87.4% occupy an intermediate position between low-and high blood hybrids.

The proposed coefficients proved to be sufficiently reliable, convenient and easy to use in practical breeding method for assessing the phenotypic consolidation of breeding group’s animals of different structural units and genotypes by the conformation type. The existence of genetic influence on the degree of phenotypic consolidation of most linear traits indicates about the possibility of effective selection of dairy cattle by body structure and morphological udder traits with intensive use of purebred Holstein sires with a high score for linear type classification.

In the process of using linear methods of classification, determining coefficients of phenotypic consolidation can sufficiently distinguish different by origin breeding groups of animals. According to the linear traits of conformation with development on the basis of established breeding situation of effective measures to improve the unconsolidated traits in the direction of desired type.