Inheritance of some economic traits and their relationship with first lactation 300 days milk yield in Friesian X Sahiwal crossbred cows

摘要

The economic viability of a dairy animal depends not only on its milk produciton but also on certain other economic traits. Crossbreeding with improved European dairy breeds has been efficient in introducing new genes into our cattle, thereby improving their milk production and other economic traits. Keeping this in view, the present genetic studies of 5/8 Friesian X Sahiwal cows maintained at different Indian Military Dairy Farms of northern region were taken up. The data used in the present studywere obtained from the pedigree and history sheets of 5/8 Friesian X Sahiwal cows maintained at Military Dairy Farms of Ambala, Bareilly, Dehradun, Lucknow and Meerut situated in northern zone of India. The performance records of 251 cows, sired by 12 Friesian bulls having atleast records up to second calving were collected for this study. The data were spread over a period from 1980 to 1986. In the present investigation four growth traits viz. body weight at 13 week's of age (BW13), body weight at 26week's of age (BW26), body weight at 52 week's of age (BW52) and body weight at first calving (BWFC), three reproduction traits viz. age at first calving (AFC), first calving interval (FCI) and breeding efficiency (BE), three production traits viz. firstlactation 300 days milk-yield (MY300), first lactation peak yield (PY) and first lactation length (FLL) and two production efficiency traits viz. milk yield per day of first calving interval (MY/FCI) and milk yield per day of age at first drying (MY/AFD) were considered.