EVALUATION OF PHENOTYPIC AND GENETIC PARAMETERS RELATED TO CLASSIFICATION BY TYPE AND PRODUCTIVITY OF COWS OF THE DAIRY

Abstract: Type classification on was performed for cows of the dairy population in Bulgaria by using experimental linear-descriptive system which includes five group of traits – general appearance milk forms, body capacity, legs and hoofs and milk system. Cows of 20 different breeds and kinds of crosses were assessed by the methodology applied in Сanada and it is applied in Bulgaria at the recommendation of a FAO commission in connection with a conducted experiment. An object of the study were 1972 cows and logically the cows of Holstein-Friesian breed originating from USA, Canada and Israel had the highest score. The phenotypic correlations between the end score and the groups of traits had high values- from 0.654 tо 0.964 and those with the milk productivity (milk and butterfat) varied from-0.123 tо 0.606. The heritability of the type traits had low values- from 0.002 tо 0.213 and corresponded with those obtained by other authors. The variance analysis for the end score showed that the age at first calving, the year (P<0.05) and the herd and breed (P<0.001) had a significant effect