Effects of non-genetic factors on production performance traits in Hardhenu crossbreed cattle

The data on 862 Hadhenu cattle sired by 63 pertaining to production performance traits up to five lactation were collected from history cum pedigree sheets maintained at Cattle Breeding Farm (CBF), Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar over a period of 20 years from 1997 to 2016. Analysis of variance done by restricted maximum likelihood method of Harvey (1990) using mixed linear model in which fixed effect of period, season of calving and random effect of parity was taken into consideration. The overall least-squares means for production performance traits viz. lactation milk yield (LMY), lactation milk yield-305 (LMY-305), lactation length (LL), peak yield (PY), average daily milk yield (AMY), milk yield per day of calving interval (MCI), milk yield per day of age at second calving (MSC) persistency, age at first calving (AFC), service period (S.P), calving interval (CI) and dry period (DP) were 3111.81± 110.17 kg, 2929.45±90.63 kg, 310.57±6.48 days, 14.65±0.48 kg/day, 9.92±0.24 kg/day, 7.80±0.23 kg/day, 1.93±0.07 kg/day, 208.94±5.86 days, 1235.22±19.53 days, 113.85±4.55 days, 401.65±5.53 days and 87.19±4.08 days, respectively. With regard to production performance traits, the effect of period of calving was statistically significant on all the traits except on AFC, SP, CI and DP. While, the effect of season of calving was non-significant on all the production performance traits except significant effect on AFC, SP, CI and DP. The effect of parity was found to be statistically significant (p<0.01), (p<0.05) on all the traits except on LL, PY, SP and CI. These differences in these traits might be attributed to variation in managemental practices and feeding regimes being followed at the farm. Moreover, the performance records of an animal should be corrected for classifiable non-genetic sources of variation, which is essential for obtaining precise estimates of genetic parameters.