Analysis of lifetime performance in Karan Fries Cattle

Present investigation includes the study of the effect of genetic and non-genetic factors and estimation of genetic parameters with respect to lifetime production and reproduction traits of Karan Fries cattle. Data consisted of a total of 5878 lactation records on 1988 cows over a period of 32years (1981 to 2012), maintained at ICAR-NDRI, Karnal. Overall least-squares meansfor LT2 (kg), LT3 (kg), LT4 (kg), LT5 (kg), ALTMY(kg), PL(days), HL(days), MY/PL(kg/day), MY/HL(kg/day), BE (%), LTDPR were found to be 7907.57±121.21, 12714.68±226.90, 17720.46±338.52, 22282.97±529.00, 15946.45±256.85, 1510.36±21.46, 2571.25±27.31, 9.87±0.11, 5.70±0.07, 89.30±0.84, 0.37±1.22, respectively. Both production and fertilitylifetime traits were significantly affected by different factors viz. season of birth, period of birth, genetic group and normal lactations completed. LSANOVA heritability estimates of LT2, LT3, LT4, ALTMY, MY/PL, MY/HL, BE, LTDPR, PL and HL were 0.29±0.09, 0.30±0.12, 0.29±0.17, 0.17±0.08, 0.21±0.08, 0.27±0.09, 0.20±0.08, 0.09±0.10, 0.10±0.08 and 0.03±0.06, respectively. Heritability estimates indicated that lifetime fertility traits were less affected by additive gene action. Genetic correlation estimates indicated unfavourable positive correlation between lifetime fertility and production traits.