Effect of supplementing isobutyrate and fibrolytic enzymes on in-vitro degradibility of alkali treated wheat straw

The present study was conducted to find out the effect of incorporating isobutyrate and exogenous fibrolytic enzymes(EFE) in urea and sodium hydroxide treated wheat straw on in vitro degradability. Chopped wheat straw treated with 4% (w/w) of urea or 3% NaOH. Finely ground (1 mm screen) wheat straw, urea treated wheat straw and NaOH treated wheat straw were supplemented with pure cellulase and xylanase mixed in 50:50 proportion at 0, 1.5, 3, 6 g/kg DM of straw and isobutyrate at 0, 0.75 and 1.5% of substrate in a 4x3x3 factorial design. IVDMD of untreated (P<0.05), urea treated (P<0.01) and NaOH treated (P<0.05) wheat straw without isobutyrate supplementation was significantly higher on 3 and 6 g EFE/kg than zero and 1.5 g EFE/kg DM of straw and similar trend was observed for NDFD. IVDMD and NDFD were significantly (P<0.05) increased by 8.05 and 13.01%; 6.29 and 8.78%; 5.50 and 6.27% in untreated, urea and NaOH treated wheat straw respectively. Thus it was concluded that different levels of EFE or BCFA supplementation improved degradability of IVDMD and IVNDFD of wheat straw, 4% urea treated wheat straw and 3% NaOH treated wheat straw. IVDMD and IVNDFD of wheat straw invariably improved (P<0.01) by urea and NaOH treatments.