IMPROVEMENT OF NUTRITIVE-VALUE OF BARLEY STRAW BY TREATMENT WITH AMMONIA AND SULFUR-DIOXIDE

Barley straw was treated with anhydrous ammonia (30 g/kg DM) for 28 days at 20-degrees-C and/or sulphur dioxide (40 g/kg DM) for 24 hours at 20-degrees-C to study the effect on the nutritive value. Barley straw was moistened with water (300 or 450 g/kg DM) before the treatment. Digestibility Of the sample was measured with nylon bags suspended for 48hours in the rumen of Tokara goats fitted with a rumen cannular and fed on alfalfa hay. Ammonia and NH3.SO2 treatments improved the crude protein content of barley straw by approximately 3.5-fold. Contents of NDF and. hemicellulose were reduced by ammonia and NH3.SO2 treatment, however ADF and cellulose contents were slightly affected. Lignin and silica contents were reduced by ammonia and NH3.SO2 treatments. These two treatments improved the digestibilities in sacco of barley straw and its cell wall components. Mild application of sulphur dioxide to ammoniated barley straw showed similar improvement in nutritive value over ammoniation alone. Sulphuration alone less affected the nutritive value of barley straw compared to the other treatment. Improvement in digestibility was strongly related to decrease in contents of lignin and silica and increased digestibility of lignin.