Effect of alkali and (or) steam treatment of wheat straw or cellulase augmented concentrate mixture on rumen fermentation in goats

Abstract

Four diets; untreated wheat straw plus concentrate mixture (CS), sodium hydroxide (5%, w/w) treated straw plus concentrate mixture (CA), sodium hydroxide (5%, w/w) and steam pressure (1 kg, cm −2, 1 h) treated straw plus concentrate mixture (CAS), and untreated straw plus cellulase augmented concentrate mixture (CES), were offered to goats to measure intake and ruminal parameters. The rumen fluids withdrawn at 0, 1, 2, 4, 6 and 8 h post feeding were analysed for pH, TVFA and its fractions as well as nitrogen fractions. The consumption of treated straw in CA or CAS groups was increased ( P < 0.01) over untreated straw. Similarly the total dry matter intake per day, per 100 kg body weight or per kg W 0.75 was higher ( P < 0.01) in CAS than in other groups. The ruminal pH was higher ( P < 0.01) in CA groups but lower ( P < 0.01), in CAS than in other groups, while TVFA concentration remained higher ( P < 0.01) in both CA or CAS diets compared with CS or CES diets. The fractional VFA remained similar amongst treatment groups. However, NPH, NH 3-N and soluble-N were lower ( P < 0.01) in CA or CAS groups than in others. Total-N and protein-N content remained similar amongst treatments. It is concluded that alkali plus steam treatment of wheat straw was the best method to improve the rumen fermentation process and enhance the availability of energy from native straw.