Islamic Republic of Iran.

Samples of grass pea seed (Lathyrus sativus) were prepared and analyzed for some chemical composition and as well for their anti-nutritional factors. The rumen degradability coefficients and post ruminal digestibility of dry matter and crude protein of unheated vs. oven heated samples were determined, employing in situ and in vitro techniques. Results indicated that grass pea seed contained a considerable level of crude protein (36%). The process of heating reduced (P< 0.05) tannins and Oxalyl DiAminoPropanoic acid (ODAP) content in grass pea seeds. Heat processing, especially 3 hours of heating, increased (P< 0.05) the slowly degradable fractions of the seed. Ruminal disappearance of DM and CP occurred at a lower rate (P< 0.05) for the heated grass pea seed than for the unheated seed. Heat processing did not affect the production of some such nutritional parameters (estimated through gas production method) as DOM, ME, NEL, SCFA and MP production (P> 0.05). It was concluded that grass pea seed was of a substantial potential as a protein source in ruminant nutrition with its heat processing resulting in positive effects on its DM and CP digestibility