Buckwheat (Fagopyrum sagittatum) has long been used as a livestock and poultry feed, but, unfortunately, little data is available on its use. The literature suggests that buckwheat has reasonable feed value, roughly comparable to oats. The grain contains 11-13% crude protein and is the best source of lysine among the feed grains, and is the only one not lysine deficient. The proteins of buckwheat are of high biological value proteins with essential amino acids making up over one third of the total protein. 

Buckwheat grain is considered to have lower feed value than grain of cereal crops because of its relatively high fiber content and low digestible nutrients. Buckwheat also contains fagopyrin, a compound which causes photosensitization of light-skinned animals. High levels of buckwheat have resulted in an increased incidence of sun-burned broiler chickens arriving at the processing plant.

ADDITIONAL RESOURCES

Alternative field crops manual - Buckwheat (University of Wisconsin)

Buckwheat (Agriculture and Agri-Food Canada)

Buckwheat - Production and Management (Manitoba Agriculture, Food and Rural Initiatives, Canada)

Buckwheat cover crop handbook (Ontario Ministry of Agriculture, Food and Rural Affairs)