Genetic Studies on Lifetime Traits of Tharparkar Cattle at Beechwal Farm in Bikaner

Abstract

Data consisting of 284 lactation records from Tharparkar herd maintained at Beechwal farm spread over a period of eleven years (2006 to 2016) were utilized to examine environmental and genetic factors affecting lifetime traits viz. herd life (HL), productive life (PL), lifetime parity, number of days in milk (NDM), lifetime milk yield (LTMY) and milk yield per day of lactating life (MYPDLL) and consequently estimate genetic and phenotypic parameters. The overall means and standard errors for HL, PL, NDM, LTMY and MYPDLL were 3080.55 ± 84.34 days, 1903.17 ± 77.17 days, 1279.52 ± 55.48 days, 9414.55 ± 406.5 kg and 5.32 ± 0.30 kg, respectively. The respective heritability estimates were 0.80±0.44, 0.73±0.32, 0.76±0.41, 0.50±0.39 and 0.69±0.37. Highly significant (P≤0.01) effect of period of first calving was observed on lifetime traits except lifetime parity and milk yield per day of lactating life. Non-significant (P>0.05) effect of season of first calving was reported on all lifetime traits. The regression of these traits on age at first calving was non-significant. Sire had significant (P≤0.05) effect on herd life and number of days in milk.