Pantnagar Journal of Research

Abstract

The present study was undertaken on crossbred cattle utilizing the records of 567 daughters of 57 sires, spread over a period of 30 years from 1990 to 2019, maintained at Instructional Dairy Farm of G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand to study the inheritance pattern of different economic traits. The least squares mean (LSM) along with their standard errors of age at first calving (AFC), first service period (FSP), first dry period (FDP), first lactation length (FLL), first calving interval (FCI), first lactation peak yield (FLPY), days to attend peak yield (DPY), first lactation milk yield (FLMY) and first lactation 305-day milk yield (FL305DMY) were observed as 1268.85 ±16.75 days, 267.51 ± 1.93 days, 91.56 ± 1.86 days, 369.41 ± 6.68 days, 465.80 ± 6.64 days, 13.88 ± 0.17 kg, 39.76 ± 0.78 days, 3294.64 ± 77.93 kg and 2570.74 ± 38.30 kg, respectively. Significant effects of sire were found on AFC, FLPY, DPY, FLMY and FL305DMY. Significant effect of period of calving was observed on AFC, FSP, DPY, FLMY, and FL305DMY while non-significant effect was found on FDP, FLL, and FCI. The effect of season of calving was found non-significant for all the first lactation traits under study. The heritability estimates for the traits under study AFC, FSP, FDP, FLL, FCI, FLPY, DPY, FLMY and FL305DMY were observed as 0.34 ± 0.21, 0.10 ± 0.1, 0.12 ± 0.11, 0.45 ± 0.16, 0.32 ± 0.17, 0.42 ± 0.22, 0.40 ± 0.20, 0.54±0.19 and 0.59±0.20, respectively. Thus, it can be asserted that sire and non-genetic factors have significant effect on the production and reproduction trait in crossbred cattle. It is pertinent to pre adjust the data of environmental factors for evaluating genetic parameters of economically important traits.