Department of Animal Production, Faculty of Agriculture, Jordan University of Science and Technology (JUST), Irbid, 22110, Jordan.
Trop Anim Health Prod. 2022 Nov 5;54(6):375. doi: 10.1007/s11250-022-03364-8.
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.
脂肪尾绵羊品种是中东地区分布最广泛的绵羊品种。它们具有较强的适应性，生长和胴体性状也能被接受。本研究旨在比较两种脂肪尾绵羊品种——阿瓦什和那吉迪的育肥性能、养分消化率和胴体特性。选择 30 只单胎初生的阿瓦什和那吉迪雄性羔羊（每个品种 15 只羔羊）进行育肥和胴体特性研究。研究持续 70 天（10 天适应期和 60 天数据收集期）。每天监测饲料消耗量，并在试验开始时和之后每两周记录羔羊的体重。研究结束时对羔羊进行屠宰，以评估胴体和肉质特性。氮摄入量和保留氮量在那吉迪羔羊中较高（P<0.05）。两组遗传群体之间的养分消化率相当。初始体重、终末体重、平均日增重和干物质摄入量不受羔羊品种的影响（P>0.05）。此外，饲料增重比、热胴体和冷胴体重量以及屠宰率不受品种类型的影响（P>0.05）。品种类型对羔羊肩部、腰部和肋部的比例没有影响。此外，羔羊的品种对肉质特性没有影响（P>0.05）。在解剖的腿部切割中，两个品种类型之间的腿部成分没有差异（P>0.05）。本研究结果表明，那吉迪羔羊的氮摄入量和保留氮量较高，但这并未反映在育肥性能和胴体性状上。
