Studies on Genetic and Non-Genetic Factors Affecting Performance Traits of Frieswal Cows.

A total of 601 lactation records of 205 Frieswal cows (Holstein Friesian and Sahiwal crossbred) from 1st to 4th parity over a period of 9 years from 1998 to 2006 maintained at Military farm, Jammu Cantonment (J&K, India) were used to estimate performance of reproduction and production traits and to study the effect of genetic and non genetic factors on performance traits. The overall averages for age at first service (AFS), age at first calving (AFC), gestation length (GL), dry period (DP), calving interval (CI), lactation length (LL), total lactation milk yield (TLMY) and milk yield per day of lactation length (MYDL) were estimated as 20.53 ± 0.44 months, 29.72 ± 0.45 months, 278.43 ± 1.54 days, 116.85 ± 4.40 days, 423.46 ± 6.15 days, 305.05 ± 4.51 days, 3087.00 ± 62.60 kg and 10.10 ± 0.16 kg, respectively. The effect of genetic group of sire was significant on age at first service, age at first calving, calving interval, lactation length, total lactation milk yield and milk yield per day of lactation length whereas effect of period was significant on all reproduction and production traits except for gestation length and lactation length. The effect of parity was significant only on dry period and milk yield per day of lactation length whereas effect of season was non-significant on all reproduction and production traits except for calving interval where it had significant effect.