Genetic studies on performance traits of Hariana cattle under progeny testing
Abstract
The present investigation was carried out for genetic studies on performance traits in Hariana cattle under progeny testing. The data on first lactation performance records of 422 Hariana cattle maintained at Germplasm unit, CCS HAU, Hisar; Govt. Livestock Farm, Hisar; Kurukshetra Gaushala, Hisar; Gaushala Bhiwani and Gaushala Jind over a period of 12 years from 1993 to 2004 were analysed for estimation of least squares means, effects of various genetic and non-genetic factors, heritability, genetic and phenotypic correlations. The breeding values of different sires for various performance traits were estimated and product moment and rank correlations among estimated breeding values were calculated. The traits studies were age at first calving (AFC), first service period (FSP), first calving interval (FCI), first lactation milk yield (FLMY), first lactation length (FLL), first lactation peak yield (FPY) and first dry period (FDP). The least squares means for AFC, FSP, FCI, FLMY, FLL, FPY and FDP were 1599.08±16.93 days, 210.60±07.09 days, 492.02±07.09 days, 875.27±25.49 kg, 245.35±04.98 days, 5.03±0.21 kg and 248.47±07.52 days, respectively. The set of sire and period of calving significantly affected AFC and FPY only, while the effect of herd was significant for all the traits. Effect of season of calving and regression of all the traits on AFC was found to be non-significant.
BIBLIOGRAPHY The estimates of heritability of AFC, FSP, FCI, FLMY, FLL, FPY and FDP were 0.19±0.08, 0.13±0.07, 0.14±0.07, 0.14±0.07, 0.13±0.07, 0.14±0.07 and 0.08±0.06, respectively. Correlation of AFC with other reproductive traits were low positive while, genetic correlations among FSP, FCI and FDP were positive and high. Among production traits genetic correlations of FLMY with FLL and FPY were moderate and positive while, phenotypic correlations of FDP with FLMY, FLL and FPY were significant and negative. AFC had negative correlation with FLMY and FPY while, there was moderate positive genetic correlation between FSP and FLMY.
The estimated breeding values of sires for AFC, FSP, FCI, FLMY, FLL, FPY and FDP were ranging from -790.11 to 439.77 days, -73.56 to 71.59 days, -75.29 to 78.62 days, -454.07 to 437.00 kg, -59.52 to 56.14 days, -2.42 to 8.57 kg and -83.02 to 95.78 days, respectively. In general, lowest ranked sires were in first set and top ranked sires were in set 4. Product moment (-0.31) and rank correlation (-0.32) among estimated breeding values for sires for AFC with FLMY were moderate in magnitude.
It may be recommended that to improve over all reproduction and production traits in Hariana cattle selection should be based on family and/or progeny testing and in addition to selection better feeding and managemental practices should be adopted. Sequential selection should be recommended first on the basis of age at first calving and then on the basis of first peak yield, first lactation length and first lactation milk yield for overall improvement in Hariana cattle.