Appraisal of linear type traits for reproductive efficiency in Sahiwal cows

Abstract

Sahiwal cows were scored for 13 linear type traits to identify the indicators for reproductive performance of the cows. The reproductive efficiency was measured in terms of inter-calving period from first to fourth calving, The type scores were standnrdized for stage of lactation, age at first calving and scoring. The nleall scores of linear type traits varied from 72.68±0.79 to 81.17±0.82 points. The estimates of heritability for most of the type traits were medium to high and indicated the existence of large additive genetic variability for these traits in this bred. The phenotypic correlation of linear type traits with reproductive efficiency ranged between 0.01±0.10 and -0.30±0.09. All the 13 linear type traits accounted for 22.96% of the variability in reproductive efficiency of Sahiwal cows. Step-wise regression analys is revealed that 75% of the variation accounted by all linear type traits in reproductive efficiency could be predicted by a sub-set of 4 traits which included stature, chest and body, pelvic angle and udder depth. It was concluded that in the absence of records, the reproductive performance of Sahiwal cows can be judged at an early age with the help of some linear type traits.