Genetic parameters of lineary scored conformation traits of Polish Black-and-White cows
2003
Zarnecki, A. | Morek-Kopec, M. | Jagusiak, W.
The classification records of 87,352 Black-and-White cows collected between 1995 and 2000 were analysed. The linear evaluation system included 15 traits scored from 1 to 9, height measured at rump, and the final score made of four breakdown traits. Linearly scored traits varied much more than the remaining traits ranging from 15.7 percent for body depth to 22 percent for central ligament. The mean scores for teat length and fore teat placement were much lower than the scores for muscularity, dairy character and chest widith. The phenotypic correlations between traits were, in general, smaller than the genetic correlations. Highest heritability was obtained for height measure at rump. Heratabilities of breakdown traits were high to moderate. The highest was heritability of size. Heriability of final score reached almost 0.30, slightly lower was heritability of conformation and dairy character, and the lowest was heritability of udder and legs. The final score was genetically correlated with its component traits, especially with conformation and dairy character. Dairy character was correlated with body depth and chest widith. Some of udder traits were genetically corelated, especially udder height with udder widith and central ligament with rear udder height and udder depth. The estimated parameters indicate that some conformation traits can be improved
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