Vol. 10, Special Issue 12 (2021)

Author(s):
Priyadharshini M, Anilkumar K and Jamuna Valsalan

Abstract:
The present study was carried out to study the significant effect of genetic and non-genetic factors on age at first calving (AFC) and first lactation milk yield (FLMY) in crossbred cattle of Kerala. The first lactation records of 898 crossbred cows sired by 203 bulls distributed over a period of 18 years (2002-2019) collected from different field centres of ICAR-Field Progeny Testing Scheme Kerala Veterinary and Animal Sciences University (KVASU). The effect of various genetic factors such as sire groups and batches whereas non-genetic factors including the period, season of birth for AFC, period, season and age at first calving for first lactation milk yield (FLMY) and source of sire for both AFC and FLMY were analyzed through Least squares analyses using Harvey software. The present study revealed that overall least square means (±standard error) for AFC was 1041.66± 6.73 days and for FLMY 2780.17 ± 15.72kg. The batches of sire had significant influence (P<0.01%) on AFC and FLMY. The period and season of birth was found to have no significant effect on AFC. Effect of period of calving was significant (P<0.05%) on FLMY. However, season of calving and classes of AFC was found to have non-significant influence on FLMY. The genetic group of sire and sources of sire showed non-significant influence on both traits under study.