Document Type : Research article
Authors
1
Department of Animal Production, Faculty of Agriculture, Al-Azhar University, Assiut, Egypt
2
Animal Production Research Institute, Agricultural Research Center (ARC), Cairo, Egypt
3
Department of Animal Production, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt
Abstract
The objective of this study was to obtaindirect heritability(h2a),maternal heritability (h2m), permanent environmental (pe2) effect and estimated breeding values (EBVs)forpre-weaning body weight at birth (BW0/Kg), body weight at 30 days of age (BW30/Kg), body weight at 60 days of age (BW60/Kg), weaning weight (WW/Kg): body weight of calf at weaning and average daily gain (ADG/kg) of 1376 Friesian calves progeny of 33 sires and 284 dams during the period from the years 2009 to 2020, which bred at El-Karada Experimental station, Animal Production Research Institute (APRI), Agricultural Research Center (ARC), Dokki, Giza, Egypt. Pre-weaning growth traits are subject to the very clear influence of non-genetic factors included sex of calf, parity of dam,year and season of calving. The direct heritability h2a estimates for all growth traits under study were moderate. Estimates of h2a were 0.24 for BW0, 0.21 for both BW30 and BW60, 0.19 for WW and 0.23 for ADG. Estimates of h2m were 0.08 for BW0, 0.10 for BW30, 0.05 for BW60, 0.04 for WW, and 0.06 for ADG. The portion of pe2 also was low, it was 0.049 for BW0, 0.064 for BW30, 0.041 for BW60, 0.044 for WW and 0.034 for ADG. Ranges of EBVs for Friesian calves were 4.585 kg for BW0, 6.821 kg for BW30, 9.075 kg for BW60, 9.459 kg for WW and 1.159 kg for ADG. The accuracy of minimum and maximum calves EBVs ranged from 56 to 79 %. Based on the results of the current study, improvement for these traits could be achieved through well-planned genetic improvement through selection for best animals according to their breeding values. Further investigation on the same traits using many data is required to reveal a more accurate and reliable genetic evaluation.
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