In vitro gas production of five rations of different maize silage and concentrate ratios influenced by increasing levels of chemically characterized extract of Salix babylonica

Abstract

This study was carried out to assess the effect of the chemical substances of Salix babylonica (SB) extract on in vitro rumen fermentation of five mixed rations with different maize silage to concentrate ratios. Fifty-nine compounds were identified in SB extract using the retention time and mass spectral technique. Interactive effects were noted (P < 0.001) for the asymptotic gas production (GP) (b), the rate of production (c), the initial delay before GP begins (L), pH, dry matter digestibility, metabolizable energy (ME), organic matter digestibility (OMD), short chain fatty acids (SCFAs), gas yield at 24 h (GY24), microbial crude protein, and in vitro GP. Both 1.2 and 1.8 mL SB/g DM had the highest (P < 0.05) b and c values. Addition of 1.2 and 1.8 mL SB/g DM linearly improved (P < 0.001) ME, OMD, SCFAs, and GY24. It could be concluded that, based on the highly detected interaction effects between ration types and extract doses for fermentation parameters and GP, the most effective dose of SB varied between incubated total mixed rations. However, the ration of 25% silage and 75% concentrate had the highest nutritive value, especially at doses of 1.2 to 1.8 mL SB/g DM total mixed ration.