Genetic and Phenotypic Parameters of Milk Production Traits of Crossbred Cattle in a Selected Farm of Bangladesh

Abstract

3 Abstract: The study was conducted in Milk and Cattle Improvement Farm, Bogra, Bangladesh from 1995 to 2003 with a view to estimate genetic and phenotypic parameters of crossbred cattle. The reproductive traits considered in the study were services per conception (SPC), age at first heat (AFH), age at first calving (AFC), gestation length (GL), calving interval (CI), post parturition heat (PPH) and birth weight (BW). Heritability was calculated from parental half-sib relationship. The average mean of SPC, AFH, AFC, GL, PPH, CI and BW were 2.76±0.13, 1223.60±62.47, 1751.02±71.79, 277.61±0.58, 105.80±6.08, 554.59±17.85 days and 22.18±0.23 kg, respectively. The heritability estimates of SPC, GL, PPH, CI and BW were 0.08±0.05, 0.31±0.08, 0.14±0.06, 0.38±0.05 and 0.33±0.09, respectively. The repeatability estimates of SPC, GL, PPH and CI were 0.46±0.08, 0.012±0.6, 0.35±0.09 and 0.022±0.04, respectively. The effects of genetic groups on various traits were non-significant except PPH (p<0.001). The results of the study revealed that the Local Crossbred cows are late maturing animals with a long inter-calving interval. High services per conception indicate their poor fertility. However, high magnitude of heritability estimates of some traits indicates additive genetic variance is pronounced and good response to selection can be achieved for these traits.