Estimation of Genetic and Phenotypic Parameters for Growth Traits of Friesian Cattle Raised in 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(h 2), genetic correlations(r G) , maternal correlations (r m) and phenotypic correlations(r P), 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 (h 2 a) 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 (h 2 m) were 0.12±0.35, 0.08±0.49 and 0.18±0.71, respectively. The permanent environment (P 2) was 0.021±0.70, 0.030±0.77 and 0.058±0.72 for BW, WW and DG, respectively. Phenotypic correlation (r P) were 0.99m while, direct genetic correlation (r g) are ranged from 0.56 to 0.96.While, maternal correlations (r m) 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.

Estimation of direct and maternal genetic parameters for pre-weaning growth traits in Friesian calves

“…Concerning maternal heritability (h 2 m), estimates of h 2 m were lower, which were 0.08 for BW0, 0.10 for BW30, 0.05 for BW60, 0.04 for WW, and 0.06 for ADG. Similar results were obtained by Atil et al (2005), Sanad and Gharib (2017), Sahin et al (2017) and Ibrahim et al (2019) for BW0 and WW. These results indicated that this component has little influence on the phenotypic variance.…”

“…As shown in Table (1) estimates of CV% for all studied growth traits were considered moderate and almost equal ranges from 11.582 to 17.363%. These estimates are within the ranges reported by Oudah and Zainab (2010), Faid-Allah (2014) and Sanad and Gharib (2017). In this regard, the estimates of CV% may reflect a reasonable variation of growth traits among individuals, which enhanced the possibility of utilizing such variation to improve the body weight productivity of calves through phenotypic selection.…”

“…Estimates of h 2 a were found to be 0.24 for BW0, 0.21 for both BW30 and BW60, 0.19 for WW and 0.23 for ADG. Similar ranges for (Friesian and Friesian Holstein) calves' body weight were observed by Ghonelm et al (2008) 2014) and Sanad and Gharib (2017).The magnitude of direct genetic variances and associated heritability currently obtained were generally high for BW0, BW30, BW60, WW and ADG which implied that generally there is sufficient genetic variation to implement genetic improvement through well-planned selection. However, h 2 a estimates of the current study were lower than the high estimates reported by Ghonelm et al (2008) for BW60, El-Arain et al (2014) for BW30.…”

“…Means, standard deviation (SD), coefficients of variation (CV %), minimum and maximum for pre-weaning growth traits (BW0, BW30, BW60, WW and ADG) of Friesian calves are presented in Table (1). Actual means of pre-weaning growth traits are within the ranges, reported in Egyptian studies, especially under the conditions of government farms (Faid-Allah, 2014;Oudah and Zainab, 2010;Sanad and Gharib, 2017; for BW0, BW30, BW60, WW and ADG. Nevertheless, these means were relatively lower than that reported by other Egyptian studies, whether for the same genotype (Friesian) or Holstein cattle Atil et al (2005) and El-Arain et al (2014) for BW0, BW30, BW60 and WW reported.…”

“…Nevertheless, these means were relatively lower than that reported by other Egyptian studies, whether for the same genotype (Friesian) or Holstein cattle Atil et al (2005) and El-Arain et al (2014) for BW0, BW30, BW60 and WW reported. on contrast, these means were relatively higher than that reported by other Egyptian studies whether, for Friesian and Holstein cattle under a commercial system (El-Arain et al, 2014;Sanad and Gharib, 2017) ranged from 0.556 to 0.656 kg for ADG, and (Faid-Allah, 2014;Ghonelm et al, 2008;Sanad and Gharib, 2018) ranged from 74.4 to 82.47 kg for WW. In this respect, the differences in means are possibly due to one or more of the following reasons such as: different climatic conditions, management practice, genetic and phenotypic differences (El-Arain et al, 2014;Hossain et al, 2018;Ibrahim et al, 2019).…”