Performance appraisal and genetic parameter estimation of all lactation traits in Karan Fries cattle

摘要

Present investigation comprehends the study of the effect of genetic and non-genetic factors and estimation of genetic parameters of Karan Fries cattle with respect to production and reproduction traits across all lactations. Data consisted of a total of 5878 lactation records on 1988 cows over a period of 32 years (1981 to 2012), maintained at ICAR-NDRI, Karnal. Overall least-squares means for CFS(days), SP(days), LL(days), CI(days), 305MY(kg), TMY(kg), MY/LL(kg/days), MY/CI(kg/days) and DPR were found to be 78.21 +/- 1.59, 115.46 +/- 2.14, 326.57 +/- 2.60, 403.91 +/- 2.54, 3634.78 +/- 30.91, 3976.77 +/- 41.03, 12.19 +/- 0.08, 10.28 +/- 0.08 and 0.37 +/- 0.80, respectively. Both production and fertility traits were significantly affected by different factors viz. season of calving, period of calving, parity and genetic group. LSANOVA heritability estimates of SP, CI, LL, CFS, DPR, 305MY, TMY, MY/LL, MY/CI were 0.18 +/- 0.08, 0.15 +/- 0.07, 0.11 +/- 0.05, 0.10 +/- 0.09, 0.07 +/- 0.07, 0.39 +/- 0.09, 0.26 +/- 0.07, 0.35 +/- 0.08 and 0.42 +/- 0.10, respectively. Heritability estimates indicated that fertility traits were less affected by additive gene action. Genetic correlation estimates indicated unfavourable positive correlation between fertility and production traits.