Evaluation of castor (Ricinus communis) seed cake in the total mixed ration for sheep.

Abstract

Castor (Ricinus communis), a tropical plant, is mainly cultivated for the production of non-edible oil used in the manufacture of detergents, cosmetics, pharmaceuticals, lubricants and, sometimes, as a laxative. India is the world's largest producer of castor seed with an annual production of 0.59 million tonnes of seed and 0.40 million tonnes of cake (CSC).1 The residue left after oil extraction, hitherto used as organic manure, is a rich source of protein (crude protein, 29–39 g kg−1), the quality of which further improves by sieving, and could be a suitable protein substitute of costly conventional oil cakes like soybean meal in livestock diets,2 but for the presence of toxic glycoprotein, ricin.3, 4 Though detoxification by physical and chemical means was found to be promising in reducing ricin, comprehensive studies are lacking to suggest its use either as such or after detoxification as animal feed. Studies were, therefore, undertaken to see the possibility of feeding CSC to sheep either as such or after detoxification with lime.