Protein is an essential component of animal feed that the industry cannot do without. Soybean meal is used a lot and serves as a great protein source for animal diets. However, the use of (primarily) South American soy is questioned because of environmental reasons, despite efforts to make all the soy sustainable. In this section we highlight some of the protein alternatives that are currently seen as promising for livestock and fish diets. Click on the words around the soybean picture to read more about these individual alternatives.
Source : http://www.allaboutfeed.net/New-Proteins/New-proteins-which-alternatives-to-soy-show-promise-for-animal-diets/