Estimation of Genetic and Phenotypic Parameters for Growth Traits of Friesian Cattle Raised in Egypt. | ||
| Journal of Animal and Poultry Production | ||
| Article 7, Volume 8, Issue 8, August 2017, Pages 253-259 PDF (276.37 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jappmu.2017.45901 | ||
| Authors | ||
| Safaa S. Sanad; M. G. Gharib | ||
| Animal production research Institute(APRI) – Research center – Egypt. | ||
| Abstract | ||
| Growth traits (GT) of 1691 Friesian calves by 74 sires and 789 dams over a 20 years (1997 to 2016) in Alkarda Farm, Egypt. Traits studied were weight at birth weight (BW), weaning weight (WW) and daily gain (DG). Records were analyzed Multiple Trait Likelihood (MTDFREML) to estimate covariance components and Heritability(h2), genetic correlations(rG) , maternal correlations (rm) and phenotypic correlations(rP), breeding values(BV), and Epigenetic trend (EGT)for growth traits (GT) of Friesian cattle raised in Egypt. Actual mean for BW,WW and DG were 28.6kg, 92.6kg and 0.60 gm , respectively. Direct heritability (h2a) estimates for BW, WW and DG were 0.32±0.06, 0.22±0.06 and 0.34±0.85, respectively; on the same time low maternal heritability (h2m) were 0.12±0.35, 0.08±0.49 and 0.18±0.71, respectively. The permanent environment (P2) was 0.021±0.70, 0.030±0.77 and 0.058±0.72 for BW, WW and DG, respectively. Phenotypic correlation (rP) were 0.99m while, direct genetic correlation (rg) are ranged from 0.56 to 0.96.While, maternal correlations (rm) ranged from were 0.48, to 0.93. Rang of breeding value (BV) estimated of calves for BW, WW and DG were 51.5kg, 10.1kg and 31.2 kg , the BV of sire for the same traits 17.7 kg, 101.0kg and 12.0g. While the range of dams BV were 11.4kg, 17.8kg and 17.7gm respectively. The results showed that it is better to choose on the basis of the BV of calves to obtain highly genetic improvement. Generally the direction was (EGT) positive in the autumn and summer 'while it was negative in the winter and spring of the studied traits. In addition, the estimated genetic trends of Epigenetics that the genetic performance of cows is affected by the exist environmental conditions, as the influence of the season, parity and year, which has shown an impact at some levels, so, sufficient care is necessary help them to rapid their full genetic possibility by improving environmental conditions Inappropriate. This results in animals showing their full genetic potential for GT, thus increasing the efficiency of selection. We conclude from this study: Improve the performance of the animal under study by estimating the environmental and genetic factors and knowing their impact on growth performance, which will allow them to set standards for assessing the performance of the animals. The traits under study are high to medium in the values of genetic equivalence. The genetic correlations between the characteristics of the study are positive and high. The direct genetic and permanent effects are more effective in the selection process. The results show that all traits of growth have a clear potential for improved yield through direct genetic selection and more attention to environmental conditions through good care and selection based on breeding values. This results in animals showing their full genetic potential for growth traits, thus increasing the efficiency of selection. | ||
| Keywords | ||
| Friesian; Growth traits (GT); animal model; genetic parameters; Epigenetics TREND (EGT); calves | ||
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