Hydroxide upon the chemical composition and dry matter(DM) and organic matter(OM) digestibility . Rice straw was treated with 4% sodium hydroxide using 30% of DM basis moisture, and incubated at 40 ºC for 40 days., DM digestibility (DMD) was significantly affected (P<0.01) by the treatment , where DMD increased The objective of this experiment was to study the effect of physical form (long ,chopped and ground ) and washing rice straw treated with sodium from 42.32 to 45.41% , OM digestibility (OMD) and total digestible nutrient (TDN) increased(P<0.05) from 47.38 and 49.33 to 49.67 and 52.83% ,respectively. While hemicellulose content increased (P<0.05 ) from 261.71 to 268.17 gm/kg DM ,and metabolizable energy (ME) from 7.11 to 7.48 MJ/ Kg DM. The NDF and lignin contents decreased (P<0.01) from 742.73 and 141.21 to 703.01 and 96.36 gm/ kg DM respectively . While dry matter (DM) ,organic matter (OM) and ADF contents decreased (P<0.05) from 987.99,854.18 and 481.02 to 962.45 ,852.35 and 434.83 gm /Kg DM, respectively. OM ,DMD and GE were affected significantly (P<0.05 ) by treating ground rice straw with sodium hydroxide compared with chopped and long rice straw, and in hemicellulose with ground and as it is compared with chopped . While NDF content decreased (P<0.05 ) in ground rice straw treated with sodium hydroxide . OMD and ME increased (P<0.05 ) in washed rice straw treated with sodium hydroxide .While DM,OM,NDF ,hemicellulose and cellulose content were decreased (P<0.05) . Furthermore, the best treatment which improved the nutritive value and in vitro digestibility of DM and OM was associated with washed and ground rice straw treated with sodium hydroxide.
