Estimation of Genetic Parameters of First Lactation and Life Time Traits Using Sire Model and Animal Model in Crossbred Cattle

Data for the present investigation were collected from the history sheet of crossbred cattle maintained at the instructional dairy farm of G.B. Pant University of Agriculture and Technology, Pantnagar. The data pertained to 1029 crossbred cattle from 107 sires were distributed over a period of 49 years from 1966 to 2014. The overall least-squares mean of first lactation traits viz. AFC, FLMY, FLP, FDP, and FCI was estimated to be 1198.22 ± 9.78 days, 2857.00 ±38.76 kg, 334.46±3.05 days, 119.90±3.87 days, and 488.02 ± 4.26, respectively. The lifetime milk yield and lifetime lactation length were estimated as 10554.32±244.67 kg. and 1133.79±18.91 days respectively. The sire effect was significant on all the first lactation and lifetime traits, except the first lactation period. In contrast, different genetic groups were found to have no significant influence on all the traits. The season of calving was also found non-significant influence on all the traits. The period of calving was found to have a significant influence on all the traits except the first lactation period. The heritability estimates of different first lactation traits were observed from low to high. Estimates of h² obtained from multiple traits analysis using the animal model were higher than the sire model. The estimates of genetic and phenotypic correlations were obtained from analysis using sire and animal models, estimates obtained from both sire and animal models indicated almost the same trend.

• The least-squares means and heritability of first lactation traits and life time traits were estimated

• Estimates of h² obtained from multiple traits analysis using the animal model were higher than the sire model.