APPLICATION OF LINEAR METHOD OF EVALUATION IN HOLSTEIN-FRIESIAN COWS

Abstract

The evaluation of a type’s conformation is a preliminary indicator of lactation, longevity and reproductive performance. Linear assessment belongs to the group of selection measures and consists the basis for evaluation and selection of genetically high-quality breeding heads. The cows should preferably be evaluated during the first lactation, 30 to 150 days after calving. The main objective of our research was a visual assessment of HolsteinFriesian dairy cows, 352 heads in total, on two major farms in the Republic of Macedonia, using a linear evaluation method. The cows in Farm 1 were kept in a loose system of rearing, while the cows in Farm 2 were kept in a tied system of rearing. The following linear features were evaluated: format, chest width, body depth, dairy character, rump position, rump width, rear legs – back view, rear legs – side view, foot angle, fore udder attachment, front teats’ positioning, teats’ length, udder depth, rear udder height, suspensory ligament, rear teats’ positioning and overall condition evaluation, which were then reduced to 4 aggregate features. The analysis of the data obtained, yielded the following average values of those aggregate linear features for Farm 1: format 5.79, dairy character 5.84, legs and dewclaws 5.83, udder 5.76; and for Farm 2: format 5.14, dairy character 5.42, legs and dewclaws 5.38, udder 5.36. Thereby we can draw the conclusion that the values of the aggregate linear features are within the average, being insignificantly higher in Farm 1 with the loose system of rearing. The average milk quantity in the period of 305 days was 7,374 kg per cow in Farm 1 and 6,895 kg in Farm 2