Background: Jatropha curcas, a non-edible oil plant, is being promoted as a biofuel plant in a number of countries in tropical and subtropical regions. The kernel meal left after extraction of the oil is a potentially protein-rich feed ingredient. However, the presence of highly toxic phorbol esters limits its use. Degradation of J. curcas phorbol esters by rumen microbes, using an in vitro rumen fermentation system, has been investigated in this study.
Results: The difference between phorbol ester contents in the residues obtained with and without substrates at 0, 24, 48 or 72 h of the incubations was statistically similar. Phorbol esters did not affect either the gas or short chain production in the in vitro rumen fermentation system.
Conclusions: Rumen microbes can not degrade phorbol esters. In addition, the phorbol esters do not adversely affect rumen fermentation. Ruminants are expected to be as prone as monogastric animals to the toxicity of Jatropha seeds.