Mini review: breeding Awassi and Assaf sheep for diverse management conditions

Abstract

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.

Review: Adaptation of animals to heat stress

“…Indigenous sheep breeds adapted to arid and semi-arid regions possess morphological characteristics such as carpet type wool, which helps to provide better protection from direct solar radiation, and this type of wool also allows effective cutaneous evaporative heat dissipation (Mahgoub et al, 2010). The fat tail observed in sheep is also recognized as a morphological adaptation for better heat transfer (Gootwine, 2011).…”

Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding

“…Further, haplotype 1 was present in many breeds [75], suggesting that this haplotype may be widespread among domesticated sheep. This would enable genetic progress in most populations without the need for time-consuming steps like introgression of the allele through multiple generations of marker-assisted backcrossing [169,170], which is additional good news for the use of this genetic marker test as an intervention for OvLV.…”

Effect of management factors on reproductive and milk production performance of a dairy sheep breed adapted to low-input management systems

“…"Blind" mastitis treatments, the non-usage of dry-period antibiotics and non-steroid anti-inflammatory drugs, as well as the absence of an integrated management for subclinical mastitis were the case in most farms, against the already established guidelines for udder health management (Fthenakis et al, 2012;Fragkou et al, 2014). Although good milking practice was not always the case, the frequency of clinical mastitis cases cy (Rhind et al, 1980;Viñoles et al, 2009;Gootwine, 2011;Fthenakis et al, 2012).…”