Phenotypic and genetic relationship of the linearly evaluated type traits and milk yield during the first lactation of 305 days
2010
Ljiljana Samolovac | Radmila Beskorovajni | Radica Đedović | Petar Stojić
The modern dairy cattle breeding programs, along with the industrial traits, also include an array of secondary traits: the body development and type among others. The importance of the aforementioned traits is reflected in the indirect relationship with the herd’s high milk yield ability along with the preserved reproductive ability and longevity. The linear type evaluation was carried out during 1998 and 1999 on a sample of 2976 first- calves cows of the black-pied breed (the average HF gene contribution in the tested sample was 73%), the daughters from twenty four different sires, that had their first lactation on one of the seven "Agricultural Corporation, Belgrade" farms. The evaluation was performed during the 30-150 day period from the beginning of the first lactation. The evaluation included fourteen traits, in a one to nine interval. The research analysed phenotypic and genetic correlation between the type traits and industrial traits: milk yield, the milk fat yield and quality, and the 4% FCM yield during the first lactation of 305 days in milk. It has been established that there is very small positive coefficient of phenotypic correlation between the two groups of traits, and a negative coefficient of genetic correlation of different magnitude.
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