School of Biosciences,University of Nottingham,Loughborough,Leics LE12 5RD,UK.
Proc Nutr Soc. 2016 Aug;75(3):242-6. doi: 10.1017/S0029665116000161. Epub 2016 Apr 18.
Selective breeding and improved nutritional management over the past 20-30 years has resulted in dramatic improvements in growth efficiency for pigs and poultry, particularly lean tissue growth. However, this has been achieved using high-quality feed ingredients, such as wheat and soya that are also used for human consumption and more recently biofuels production. Ruminants on the other hand are less efficient, but are normally fed poorer quality ingredients that cannot be digested by human subjects, such as grass or silage. The challenges therefore are to: (i) maintain the current efficiency of growth of pigs and poultry, but using more ingredients not needed to feed the increasing human population or for the production of biofuels; (ii) improve the efficiency of growth in ruminants; (iii) at the same time produce animal products (meat, milk and eggs) of equal or improved quality. This review will describe the use of: (a) enzyme additives for animal feeds, to improve feed digestibility; (b) known growth promoting agents, such as growth hormone, β-agonists and anabolic steroids, currently banned in the European Union but used in other parts of the world; (c) recent transcriptomic studies into molecular mechanisms for improved growth efficiency via low residual feed intake. In doing so, the use of genetic manipulation in animals will also be discussed.
在过去的 20 到 30 年中，通过选择性繁殖和改进的营养管理，猪和家禽的生长效率得到了显著提高，特别是瘦肉组织的生长。然而，这是使用高质量的饲料成分实现的，如小麦和大豆，这些成分也用于人类消费，最近还用于生物燃料生产。另一方面，反刍动物的生长效率较低，但通常使用质量较差的饲料成分，这些成分不能被人类消化，如草或青贮饲料。因此，面临的挑战是：（i）在使用不需要养活不断增长的人口或生产生物燃料的更多成分的情况下，保持猪和家禽目前的生长效率；（ii）提高反刍动物的生长效率；（iii）同时生产同等或改善质量的动物产品（肉、奶和蛋）。这篇综述将描述以下方面的应用：（a）用于动物饲料的酶添加剂，以提高饲料的消化率；（b）已知的生长促进剂，如生长激素、β-激动剂和合成代谢类固醇，目前在欧盟被禁用，但在世界其他地区仍在使用；（c）通过低残留饲料摄入量提高生长效率的最新转录组研究。在这样做的过程中，还将讨论动物遗传操作的使用。
