Published in Scientific Papers. Series "Management, Economic Engineering in Agriculture and rural development", Vol. 21 ISSUE 1
Written by Leontii KHMELNYCHYI, Victoria VECHORKA, Serhii KHMELNYCHYI, Igor RUBTSOV, Evgeniya SAMOKHINA, Cennadiy SMOLYAROV

The purpose of this study was to determine the heritability level of cow’s linear traits of Ukrainian Black-and-White dairy breed in herds of Ukraine, to define phenotypic relationships between linear traits and dairy productivity, and to study the impact of final assessment on traits of cow's longevity. The level of heritability coefficients of group traits testified about the efficiency of breeding on the results of cow's selection by dairy type (0,408), body (0,384), udder (0,417) and the final assessment (0,512). Heritability coefficients of descriptive traits varied by variability significantly, from 0.106 (hoof angle) to 0.477 (angularity). Correlation coefficients between group linear traits that characterize dairy type, body and udder, milk yield and milk fat for 305 days of first lactation were: 0.464 and 0.386; 0.452 and 0.463; 0.477 and 0.433, respectively. The correlation between descriptive traits and dairy productivity of cows distinguished by the high variability, from average negative (r = -0.376), between fatness and milk fat yield, to close positive (r = 0.495), between angularity and milk yield. According to longevity, economic use, and lactation, cows estimated “Very Good” were dominated by cows with lower “Good Plus”, “Good” and “Insufficient” scores, with highly significant difference, on 527-1,429, 526-1,423, and 451-1,180 days (P <0.001), respectively. Over the lifetime milk yield and milk fat, the preference was 10,050-26,012 and 373.1-941.2 kg, respectively (P <0.001). Statistically significant correlations of angularity, rear width, fore and rear udder attachment, central ligament and body condition score can be used as indirect predictors of selection to increase dairy cow productivity.

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