Growth performance and meat characteristics of the first filial Awassi-Rambouillet callipyge ram lambs.

Khaleel I Z Jawasreh,A H Al-Amareen,P Y Aad

doi:10.14202/vetworld.2019.783-788

Khaleel I Z Jawasreh, A H Al-Amareen + Show 1 more

Open Access

https://doi.org/10.14202/vetworld.2019.783-788

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Abstract

Aim:This study was designed to introduce the callipyge (CLPG) and 50% of Rambouillet sheep genes to improve meat quality and quantity of Awassi (AW) sheep.Materials and Methods:The CLPG mutation was introduced into the AW sheep through frozen semen of homozygous Rambouillet rams for the CLPG mutation. Four ram lambs from the first-generation Rambouillet callipyge Awassi (F1-RCA) and five from pure AW were recruited for a fattening trial conducted in individual pens using standard ration, following which ram lambs were slaughtered for carcass and meat evaluation.Results:Final body weight, dry matter intake, average daily gain, and feed conversion ratio were significantly higher in F1-RCA than AW. Hot and cold carcass weights and the other carcass cuts’ weights, except for the fat tail, were heavier in F1-RCA than AW. There was no difference in dressing percentage between the two genetic groups (p>0.05). All non-carcass components’ weights, except spleen, kidney, and testis, were higher in F1-RCA. Total lean, total bone, and intermuscular fat weight were greater in F1-RCA, but bone-to-lean ratio was lower in F1-RCA when compared with AW (p<0.01). No differences (p>0.05) were observed in all meat quality parameters for muscle longissimus with the exception of pH, redness color, and tenderness that were lower (p<0.05) in F1-RCA than AW. F1-RCA lambs had larger longissimus muscle area (30.9 vs. 16.9 cm2) and less leg fat depth (11.1 vs. 17.4 mm).Conclusion:The implications of this research show the potential of 50% of Rambouillet genes and the CLPG mutation to improve growth and meat characteristics in AW-Rambouillet crosses and can be used further to develop a meat-type AW with improved productivity and muscle mass.

Highlights

Awassi (AW) is a multipurpose fat-tailed sheep breed, well adapted to harsh environmental conditions, and the predominant sheep breed in Jordan, Lebanon, and the Middle East
The implications of this research show the potential of 50% of Rambouillet genes and the CLPG mutation to improve growth and meat characteristics in AW-Rambouillet crosses and can be used further to develop a meat-type AW with improved productivity and muscle mass
We introduced the CLPG mutation from CLPG Rambouillet into purebred AW sheep for the 1st time and evaluated these animals for growth and meat characteristics

Summary

Introduction

Awassi (AW) is a multipurpose fat-tailed sheep breed, well adapted to harsh environmental conditions, and the predominant sheep breed in Jordan, Lebanon, and the Middle East. The AW sheep breed suffers from inferior carcass merit and poor leg muscling [1]. With consumers requiring meat with more lean and less fat without compromising juiciness and flavor [2], heavier carcasses could be advantageous for producers by providing higher profit from meat sales and for consumers by supplying more mature meat with better quality [3]. Mutations affecting muscle growth and development have been identified in sheep. The exploitation of these mutations in breeding strategies has the potential to significantly improve lamb meat quality.

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