Fattening lambs in Mediterranean countries are produced under intensive production systems where high concentrate intake levels are reached. It is also well known that fattening lambs may present wide differences in feed efficiency, so the ability to transform the feed consumed into meat is variable and may impact the profitability of the farm and the quality of the final product obtained. Accordingly, it is essential to understand the differences in meat quality caused by divergent feed efficiency values before making recommendations to the farmers. Therefore, the aim of the present study has been to study the effects of two groups of Assaf fattening lambs with differences in feed efficiency on physicochemical parameters, fatty acid content and volatile compounds of meat. Lambs were fed a complete pelleted diet (CPD) ad libitum and slaughtered when they were 85-days old. The results obtained reveal that the less efficient lambs presented no differences in caracass and non-carcass parameters, but increased tenderness of the meat, probably caused by reduced cooking losses and higher amounts of several fatty acids (e.g., 17:0, 19:00, 20:0, c12−18:1, t10−18:1 + t11−18:1, 19:1, c11−20:1, t18:2). Other physicochemical traits such as chemical composition, pH or colour changes of meat under refrigerated storage were not significantly affected by feed efficiency in the present study, but volatiles compounds responsible of the flavor of cooked meat (e.g., 2-pentylfuran) presented a trend towards significantly lower values (P = 0.056) in low efficient lambs. All these results suggest the need for a deeper knowledge (including differential gene expression analyses and sensory characteristics) regarding the overall effects of feed efficiency on meat quality before implementing breeding programs for high efficient Assaf fattening lambs.

地中海国家的肥羊羔是在集约化生产系统下生产的，精矿摄入量很高。众所周知，育肥羔羊的饲料效率可能存在很大差异，因此将消耗的饲料转化为肉类的能力是可变的，并且可能影响农场的盈利能力和最终产品的质量。因此，在向农民提出建议之前，必须了解不同饲料效率值所导致的肉质差异。因此，本研究的目的是研究饲料效率不同的两组阿萨夫（Assaf）育肥羔羊对理化参数，脂肪酸含量和肉类挥发性成分的影响。羔羊饲喂完全颗粒饲料（CPD）他们85天大时随意随意宰杀。获得的结果表明，效率较低的羔羊的car肉和非-体参数没有差异，但是肉的嫩度增加，这可能是由于烹饪损失减少和几种脂肪酸的含量较高所致（例如17：0、19 ：00 ，20：0，c 12-18：1，t 10-18：1 + t 11-18：1，19：1，c 11-20：1，t 18：2）。在本研究中，其他物理化学特性，例如冷藏条件下肉的化学组成，pH或颜色变化，不受饲料效率的显着影响，但挥发性化合物会影响熟肉的风味（例如（2-戊基呋喃）在低效羔羊中呈现出明显降低的趋势（P = 0.056）。所有这些结果表明，在实施高效的阿萨夫育肥羔羊育种计划之前，需要对饲料效率对肉质的总体影响有更深入的了解（包括差异基因表达分析和感官特征）。