Possibilities of implementing measures from automatic milking systems in routine evaluations of udder conformation and milking speed.

Abstract

Genetic parameters for nine udder conformation traits were estimated in first parity Danish Holstein cows by means of bi-variate linear animal models. The traits were either based on measures of teat coordinates from milking robots or linearly scored by professional classifiers. The heritabilities for the objectively measured AMS traits were higher than for the corresponding subjectively scored traits. All genetic correlations between two corresponding traits were high (rg ≥ 0.90). In addition, genetic parameters for fat and protein flow measured in milking robots, fat and protein flow measured by means of TruTest milk meters and milking speed scored by dairy farmers were estimated in first parity Danish Holstein cows using a tri-variate linear animal model. The heritability for flow measured in milking robots was the highest among the three estimates and the heritability for milking speed was the lowest. The genetic correlations between the three traits were 0.91 or higher. According to these preliminary results it is possible to use information on teat co-ordinates and fat and protein flow from milking robots in the joint Nordic genetic evaluation of udder conformation and milking speed, respectively.