The nutritive value of grasspea (Lathyrus sativus) and allied species, their toxicity to animals and the role of malnutrition in neurolathyrism

The safe use of grasspea (Lathyrus sativus) and allied species (L. cicera, L. clymenum and L. ochrus) requires a better understanding of the factors that are involved in the development of neurolathyrism. A suitable animal model is needed. The nutritional quality, seed chemical composition, the role of malnutrition, synergistic action of antinutritional factors, the toxicity of both seed and forage to animals, metabolism and tissue distribution of the toxic amino acid beta-N-oxalyl-alpha,beta-l-diaminopropionic acid (ODAP) in mammals are reviewed. Malnutrition is not necessary for the development of neurolathyrism, however, the supply of sulfur amino acids by Lathyrus spp. is limited by the combined action of several antinutritional factors and the low inherent levels in the seeds. Metabolism or excretion of ODAP and clearance from the central nervous system appear to function well under normal circumstances, while species differences exist. Interruptions to these processes and excessive concurrent demands for reduced sulfur amino acids are likely to be conducive to the onset of neurotoxicity.