GENETIC IMPROVEMENT OF MILK PRODUCTION IN EGYPTIAN BUFFALOES THROUGH SELECTION INDEXES | ||||
Journal of Animal and Poultry Production | ||||
Article 5, Volume 30, Issue 11, November 2005, Page 6565-6571 PDF (1.93 MB) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/jappmu.2005.238441 | ||||
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Authors | ||||
M. H. Hammoud,1; O. M. EI-Shafie2 | ||||
1Department of Animal Production, Faculty of Agriculture, University of Alexandria | ||||
2Animal Production Research Institute, Ministry of Agriculture | ||||
Abstract | ||||
Data relevant to 398 Egyptian buffaloes raised at Mehallet Mousa Experimental Station between 1972-1992 were utilized in this investigation to construct several selection indexes which determine the most suitable combination of age at first calving (AFC), first lactation total milk yield (TMY), first dry period (DP)and first calving interval (CI) in order to realize the most genetic improvement in TMY. Overall mean of AFC was 1167.12 days, of TMY was 1231.57 kgs, of DP was 315.50 days and of CI was 597.25 days. Heritability estimate of AFC was 0.38, of TMY was 0.43, of DP was 0.32 and of CI was 0.20. Phenotypic correlations were highly significant but mild except those between DP and each of TMY and CI were moderately negative and high positive , respectively. Similarly were the genetic correlations except that between DP and AFC which was moderately positive. The genetiC correlation between TMY and each of DP and CI were high negative and very high positive, respectively. The highest expected genetic improvement (ilG) for TMY (357.5 kgs) was obtained from the second index (12) which incorporated TMY, DP and CI. Also it recorded the highest correlation with the aggregate genotype (rrr = 1.00) and the highest reiative efficiency compared with the basic index (RE %= 125). Whereas the lowest correlation with the aggregate genotype (riT = 0.65) and the lowest relative efficiency (RE%=81) were obtained from 16 which included TMY and DP. | ||||
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