A review of nutritional and toxicological implications of castor bean (Ricinus communis L.) meal in animal feeding systems

Abstract

The nutrient-rich defatted castor meal has been tested as a potential source of protein in diets of many livestock species but has limitation due to challenges of toxins. This review was conducted to compile the relevant research information on advances in the use of raw and differently processed castor seed meal in animal feed. In this article, distribution and uses of castor and its products were identified. Research findings on the nutrients profile, principal toxins, various detoxification strategies, nutritional value and toxicity on common livestock species were compiled and reviewed. The defatted seed meal had crude protein range of 32-48%, gross energy of about 3200 kcal/kg. Ricin content was 9.3 mg/g seed, and the average RCA content was 9.9 mg/g. The meal had high activity of lectin, which produced agglutination at about 4.70 mg/ml minimum assays. Reports of detoxification strategies showed varying degrees of success but high pH, moist heating and microbial techniques appeared to exert greater effect on deactivating ricin. Detoxification strategy for the allergen component is inconclusive. Tannins and the phenolic contents were present at trace level and did not constitute notable threat. It was concluded that castor seed holds great potential as feedstuff when upgraded but such upgrading must be safe, cost-effective and labour efficient for commercial acceptability.