State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer Sheva, Israel.
J Anim Physiol Anim Nutr (Berl). 2020 Jul;104(4):1010-1023. doi: 10.1111/jpn.13298. Epub 2020 Jan 26.
Today, consumers are very health conscious and are more aware of the nutritional value of food, especially of meat, than they were in the past. The aim of this study was to evaluate the carcass parameters and meat quality of Tibetan sheep and Small-tailed Han sheep when consuming a diet of low-protein (~7%) and different energy yields (digestible energy, 8.21, 9.33, 10.45 and 11.57 MJ/kg) in the cold season. Twelve sheep of each breed were divided randomly into four treatments of different diets with three replicates per treatment per breed. Crude protein of the meat decreased linearly (p < .05), whereas energy increased linearly (p < .05) with an increase in energy level. Tibetan sheep tended to have a higher (p < .1) dressing percentage and rib eye area, while live body weight and hot carcass weight did not differ between breeds but increased linearly (p < .01) with an increase in energy level. Water holding capacity, as indicated by pressing loss and drip loss, did not differ between breeds and was not affected by dietary energy. The concentration of n-3 polyunsaturated fatty acids (PUFAs) was greater in Tibetan sheep meat but saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and n-6 PUFA did not differ between breeds. With an increase in energy content of the diet, SFA decreased (p < .05), whereas MUFA increased (p < .05). The n-6:n-3 PUFA ratio was lower (p < .001) in Tibetan sheep meat, while the atherogenic index did not differ between breeds, but tended to decrease (p < .1) with an increase in dietary energy content. The essential amino acid (EAA) content and ratio of EAA:NEAA (non-essential amino acid) were close to the world standards for healthy meat. In summary, (a) Tibetan sheep meat was preferable to Small-tailed Han sheep meat, although differences between breeds were small; and (b) some carcass parameters and meat quality were improved with an increase in dietary energy level when a low-protein diet was offered.
如今，消费者非常注重健康，对食物的营养价值，尤其是肉类的营养价值的认识比过去提高了很多。本研究旨在评估在寒冷季节，当藏绵羊和小尾寒羊摄入低蛋白（~7%）和不同能量水平（可消化能分别为 8.21、9.33、10.45 和 11.57MJ/kg）的饮食时，其胴体参数和肉质的变化。每个品种的 12 只绵羊被随机分为四个不同日粮处理组，每个处理组有三个重复。粗蛋白含量呈线性下降（p<0.05），而能量则呈线性增加（p<0.05）。藏绵羊的屠宰率和眼肌面积较高（p<0.1），而活体重和热胴体重在品种间无差异，但随着能量水平的增加呈线性增加（p<0.01）。水保持能力，如压榨损失和滴水损失，在品种间没有差异，也不受日粮能量的影响。藏绵羊肉中的 n-3 多不饱和脂肪酸（PUFA）浓度较高，但饱和脂肪酸（SFA）、单不饱和脂肪酸（MUFA）和 n-6PUFA 在品种间没有差异。随着日粮能量含量的增加，SFA 降低（p<0.05），MUFA 增加（p<0.05）。藏绵羊肉中的 n-6:n-3 PUFA 比值较低（p<0.001），而品种间的致动脉粥样硬化指数没有差异，但随着日粮能量含量的增加有降低的趋势（p<0.1）。必需氨基酸（EAA）含量和 EAA:NEAA（非必需氨基酸）的比值接近健康肉类的世界标准。总之，（a）藏绵羊肉优于小尾寒羊，尽管品种间差异较小；（b）当提供低蛋白饮食时，随着日粮能量水平的增加，一些胴体参数和肉质得到了改善。
