Evaluation of genetic trend of the Bulgarian dairy population
2009
Gaidarska, V., Institute of Animal Science, Kostinbrod (Bulgaria)
The objective of the present research was to estimate genetic trend on the productive traits - milk yield, fat % content and butter fat in milk of Black-and-White dairy cows in Bulgaria, rearing by the traditional technology, for the period of 1996 to 2005. The study included data for milk productivity from the first lactation for 29125 Black-and-White cows with a completed normal lactation (240-305 days), offspring of 473 Holstein-Friesian bulls, which was used for analyses. Based on the obtained results, it was established that the genetic trend of the Black-and-White dairy cattle population, for milk performance was +26.48 kg milk yield and +0.0043% fat content in milk, phenotypic trend was +25.65 kg of milk per cow, and +0.0500% fat in milk, and paratypic trend was - 0.83 kg of milk per cow and 0.0457% fat in milk. Irrespective of the achieved results the possibilities for genetic improvement of Black-and-White breed are not depleted yet. This is supported by both: the theoretical and practical results.
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