Variances of direct and maternal genetic effects for milk yield and age at first calving in a herd of Friesian cattle in Egypt

Abstract

A total of 2095 lactation records of Holstein Friesian cattle kept at Dalla Farm in Egypt during the period from 1988 to 1992 were used in this study. Those data were used to estimate variances from direct and maternal genetic effects. The data was analyzed by using Multiple Traits Derivative Free Restricted Maximum Likelihood (MTDFREML) according to BOLDMAN et al. (1995) using repeatability Animal Model. Two models were used: Model 1 includes month of calving, year of calving, parity as fixed effects, days open and days dry as covariates and direct genetic, maternal genetic, covariance between direct and maternal genetic, permanent environmental and residual as random effects; Model 2 is similar to Model 1, but excluding additive maternal and covariance between additive direct and maternal effects. Estimates of heritability for 305 day milk yield (305 dMY) were 0.22 and 0.23, for Model 1 and Model 2, respectively. Heritability estimates for age at first calving (AFC) were 0.77 and 0.82 for Model 1 and model 2, respectively. The removal of additive maternal genetic effects and covariance between direct and maternal genetic effects from the model increased estimates for heritability of additive genetic effects by 0.01 and 0.05 for 305 dMY and AFC, respectively. Then, the additive maternal genetic effect and covariance between direct and maternal genetic effects do not seem to make important contributions to the phenotypic variance for milk yield and age at first calving, and these effects are probably not important for genetic evaluations.

Effects of Breed, Calving Season and Parity on Productive and Economic Indices of Dairy Cows

“…On contrary to our results, Jalvingh et al (1993) concluded that, the most profitable season of calving was autumn and milk price differences was the main determinant of seasonal variation in herds. Our results regarding the effect of parity on milk yield parameters (total-MY, 305-MY and DMY) were comparable to those obtained by Khattab et al (2005), who demonstrated that second and third parities had highest 305-MY (5349 ± 53 and 4984 ± 58), respectively than first, fourth and fifth ones (4320 ± 53, 4868 ± 59 and 4389 ± 85), respectively. Also, the results of Ngodigha and Etokeren (2009) , working with crossbred cows of different Holstein Friesian inheritance (50, 75, 87.5 and 100%), found that first (4554±469 kg), second (5427±455 kg) and thirdparity dams (5139±441 kg) yielded more milk than fourth parity dams (2896±430 kg).…”

Factors affecting first lactation performance of Sahiwal cattle in Pakistan

“…Weak genetic control of the trait suggests improvement in the feeding and management may reduce the age at first calving. Some of the previous reports (MOHIUDDIN et al, 1994;JAVED, 1999;KHATTAB et al, 2005) estimated genetic control close to zero for Sahiwal in Pakistan. However, some Indian studies (TOMAR et al, 1974) reported h 2 in the medium to high range.…”

Relationships between production and fertility traits in first lactation and life time performances of Holstein cows under subtropical condition

“…(NIEUWHOF et al 1989, HARRIS et al 1992, SETTAR and WELLER 1999, FREYER and ERHARDT 2000, RIZZI et al 2002, NILFOROOSHAN and EDRISS 2004, TSURUTA et al 2005, GOSHU 2005, DAKAY et al 2006 Heritability estimates ranged from 0.22 to 0.40, 0.03 to 0.09, 0.04 to 0.14, and 0.03 to 0.12 for first lactation milk yield, calving interval, herd life and length of productive life respectively. Genetic and phenotypic correlations of production traits with herd and length of productive lives were from −0.08 to 0.91 and 0.04 to 0.55 ( VAN DOORMAL et al 1985, HARRIS et al 1992, JAIRATH et al 1995, VOLLEMA and GROEN 1996, SETTAR and WELLER 1999, CRUICKSHANK et al 2002, ROXSTRÖM and STRANDBERG 2002, HAILE-MARIAM et al 2003a, HAILE-MARIAM et al 2003b, SEELAND and HENZE 2003, NILFOROOSHAN and EDRISS 2004, KHATTAB et al 2005, TSURUTA et al 2005, GADER et al 2007.…”