Evaluation of parboiled rice by-product as a ruminant feed: in vitro digestibility and methane production

Abstract

Solid waste generated by parboiled rice industry are rice bran, rice husk and broken rice. Broken rice can be used for cattle feed as energy source. The aim of this study was to evaluate the effects of parboiling process on the in vitro rumen fermentation. The experiment was arranged in a completely randomized block design with 2 rice varieties (LIPI Go 1 and Sintanur) as blocks, 2 different soaking periods (30 and 60 minutes) as treatments and 3 replications. Parboiling treatment was significantly (P<0.05) increased crude protein, organic matter, and crude fiber, but decreased ether extract and solubility. LIPI Go 1 produced higher (P<0.05) gas (11.18%), but lower (P<0.05) gas production rate (52.38%) and methane (10.27%). Soaking rice grain for 30 and 60 minutes decreased rumen dry matter digestibility by 6.13% and 8.90% and increased post rumen dry matter digestibility by 10.41% and 10.43%, respectively. Moreover, 3.55% and 6.84% from total samples of parboiled rice treated by 30 minutes and 60 minutes soaking periods were digested in the ileum. As ruminant feed, parboiled rice decreased methane and digestibility in rumen, and increased the digestibility in post rumen and ileum.