Original scientific paper
INFLUENCE OF MILK YIELD IN FIRST LACTATION ON LIFETIME MILK YIELD OF HOLSTEIN COWS
Vitomir Vidović
; Poljoprivredni fakultet Novi Sad, Srbija
Abstract
Investigations included milk yield of 3.230 cows, i.e. 7.652 lactations of Holstein cows from 1977 to 1989. Phernotype and genetic milk yield parameters were analyses in individual lactations as well as the level of correlation between milk yield in the first and later lactations.
Participation of individual lactations in the total milk yield is quite uniform thus justifying the use of information on earlier lactations when selecting parents. High genetic correlations of the milk yield between the first lactation and the lifetime yield indicate the need for including lifetime yield as well when selecting parents according to their origin at the same ti.me applying mixed selection models. The prominent interaction between genotypes and environment, measured by phenotype correlations and repetition coefficient indicate possibilities of obtaining subjective evaluation of genetic parameters which are the most frequent consequences of environment conditions and the size of cow population.
Keywords
Hrčak ID:
162179
URI
Publication date:
26.7.1991.
Visits: 560 *