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Gootwine E 《Tropical animal health and production》2011,43(7):1289-1296
The Local Awassi, a triple-purpose breed for meat, milk, and carpet–wool production, is a low-prolific, hardy breed that is
well adapted to the unfavorable conditions of the Middle East, where it is managed under traditionally extensive to semi-extensive
conditions. Breeding work with the Awassi has included within-breed selection, crossbreeding, and gene introgression. Those
efforts resulted in a variety of Awassi-derived genotypes that successfully occupy semi-intensive as well as intensive production
systems. Thus, within-breed selection resulted in development of the “Improved Awassi”—a dairy-type Awassi strain which, under
intensive management, produces over 500 l milk/ewe annually; crossbreeding with the East Friesian breed led to the development
of the Assaf dairy breed, which exceeds the Improved Awassi in prolificacy and in year-round breeding activity, and introgression
of the B allele of the FecB locus into the Awassi and Assaf breeds resulted in the formation of the prolific Afec Awassi and Afec Assaf strains, with
prolificacies of 1.9 and 2.5 lambs born per ewe lambing, respectively. Advanced molecular genetics tools have enabled a better
understanding of how the Awassi breed was formed during domestication and have uncovered differences in its genetic structure
compared to other breeds. Implementing large-scale selection schemes that implement emerging new information on the sheep
genome, overcoming threats of inbreeding depression, and further breeding for high uterine capacity are the new breeding goals
for the Awassi, Assaf, and their derivatives. 相似文献