Legume seeds are mainly soybean, black bean, cowpea, pea, peanut and so on.

The nutritional characteristics: crude protein content of up to 20% to 40%, good protein quality, lysine is more, and methionine and other sulfur-containing amino acids are relatively insufficient, essential amino acids in addition to methionine is similar to animal protein. Nitrogen-free leachate is significantly lower than the energy feed, the organic matter digestibility of beans is more than 85%, rich in fat. Soybeans and peanuts have a crude fat content of more than 15% and therefore have a high energy value and can be used as both protein and energy feeds. The mineral and vitamin content of legume seeds is similar to or slightly higher than that of cereal feeds, with slightly higher calcium content but still lower phosphorus, rich in vitamin B1 and niacin, and deficient in vitamin B2, carotene and vitamin D.

Legume seeds contain some anti-nutritional factors, such as trypsin inhibitory factor, chymotrypsin inhibitory factor, hemagglutinin, saponin, etc., affecting the palatability of the feed, digestibility, and some of the physiological processes of animals. However, after appropriate heat treatment, it can make it inactive and improve feed utilization.