Comparison of Nutritive Values and in vitro Degradability of Steam Treated Rice Straw with Chinese Wild Rye and Alfalfa

Abstract

The study was conducted to compare the chemical composition and in vitro degradability of steam treated rice straw, alfalfa hay (AH) and Chinese wild rye (CWR).The rice strawswere treated with steam pressure, i.e. TRS-I (exposed to 15.5 kgf/cm2 steam pressure for 90 sec), TRS-II (exposed to 15.5 kgf/cm2 steam pressure for 120 sec).The results regarding chemical composition revealed that steam treated straw had higher (P<0.05) dry matter (DM), ash and acid detergent fiber (ADF) contents; lower (P<0.05) organic ma tter (OM) than AH and CWR, the ether extract (EE) were higher and neutral detergent fiber (NDF) were lower (P<0.05) in AH and TRS-II, while the crude protein (CP) were higher and acid detergent lignin (ADL) were lower (P<0.05) in AH than other groups. The concentration of acetate, butyrate and iso-butyrate were almost similar in TRS-II, AH and CWR; valeric and iso-valericwere lower (P<0.05) in CWR and TRS-I than AH and TRS-II, while the propionate and total VFA were higher in AH but similar in CWR and treated rice straw. The in vitro degradibility of DM, OM and NDF were significantly higher for AH and TRS-II while, ADF was higher for AH. Steam treated straws showed increased (P<0.05) pH and NH3-N (P<0.05), while total gas production was higher in AH and TRS-II than other groups. These findings suggest that steam treated straw had better nutrients values and degradibility over Chinese wild rye, so it could be used as forage for ruminants.