Department of Animal Genetics and Breeding, Post Graduate Institute of Veterinary and Animal Sciences, Akola-444 104, India.
*Part of M.V.Sc. thesis submitted by the first author to Maharashtra Animal and Fishery Sciences University, Nagpur.
The data on the 267 lactation records including 192 records of Sahiwal cows and 75 records of Sahiwal x Jersey crossbred cows maintained at Bull Mother Farm, Wadsa dist. Gadchiroli (M. S.) from 1989 – 2007 on basis of first, second and third more than three lactation were considered for study. The mean age at first calving in Sahiwal cows and Sahiwal x Jersey crossbred cows were 1241.36 ± 24.81 and 984.93 ± 33.13 days respectively. Decreasing trend of service period and calving interval occurs with increasing lactation number in Sahiwal and Sahiwal x Jersey crossbred. High repeatability estimates of the studied traits indicated the possibility of selecting cows based on first lactation.
Sahiwal × Jersey crossbred cows, Lactations, Reproductive traits
