EVALUATION OF HOLSTEIN CROSSBRED BULLS ON THE BASIS OF MILK FAT CONTENT OF DAUGHTERS

Abstract

Ten Holstein-Friesian crossbred bulls, ranging in exotic inheritance from 50-75% were evaluated for milk fat content using Simple Daughters Average, Contemporary Compa rison and Least Squares Means. The data on milk fat content of 103 progenies in their first lactation and 119 contemporary cows, under rural conditions and organized farms of Kerala, calved during 1995-96, formed the material for study. The sire-wise average fat content ranged from 2.90 to 3.90 for early lactation morning mi lk. Least squares analysis revealed that locations had highly significant effect on fat content of milk, while the effect of season and sire on fat percentage were insignificant. Milk fat percentage showed an increasing trend with the progress of lactation and was higher for evening milk. Two-third of cows in the early stage of lactation, recorded morning milk fat percentage, below the legal standards of 3.5, under field condition. But, even under organized farms with optimum managemental conditions, 28.38% of cows in early lactation had their morning milk fat below 3.5%. This emphasizes and need for selection of bulls on the basis of milk fat percentage also, for genetic improvement of cattle of the state