Fattening performance, nutrient digestibility, and carcass traits of two fat-tailed sheep breeds

Fat-tailed sheep breeds are the most widespread types of sheep in the Middle East. They are hardy and have acceptable growth and carcass traits. The purpose of this study is to compare the fattening performance, nutrient digestibility, and carcass characteristics of two fat-tailed sheep breeds, Awassi and Najdi. Thirty single-born Awassi and Najdi male lambs (15 lambs per breed) were examined for fattening and carcass characteristics. The study lasted 70 days (10 days adaptation period and 60 days for collecting the data). Feed consumption was monitored daily, and the body weight of lambs was recorded upon arrival to the trial area and biweekly afterward. Lambs were slaughtered at the end of the study to assess carcass and meat quality characteristics. Nitrogen intake and retained nitrogen were higher (P < 0.05) for Najdi lambs. The digestibility of nutrients was comparable between the two genetic groups. Initial body weight, final body weight, average daily gain, and dry matter intake were not affected (P > 0.05) by the lamb's breed. Furthermore, the feed-to-gain ratio, hot and cold carcass weights, and dressing percentage were not affected by breed type (P > 0.05). Breed type has no influence on the shoulder, loin, and rack percentages of the lamb. Moreover, meat quality traits were not affected by the lamb's breed (P > 0.05). In the dissected leg cut, no differences in the leg component were found among the two breed types (P > 0.05). Results of this study reveal that nitrogen intake and retained nitrogen were higher for Najdi lambs, but this was not reflected in fattening performance and carcass traits.