摘要
Nano-trace element additives, with a particle size of 1-100 nm, are absorbed directly by osmosis in animals without ion exchange. When added to the feed, they can not only promote the growth by own nutrition at the conventional size, but also greatly improve the utilization and ab-sorption rate of additives by animals. In this paper, the researches on micro-element feed additives such as nano-selenium, nano-copper, nano-zinc and nano-chromium were reviewed, which will provide basis for breeding production.