Authors : Zheng Chen, Hao Zhengli, Li Fadi, Guo Yanli and Jin Yanmei
Abstract: This study was conducted to investigate the effects of adding Mannan-Oligosaccharide (MOS) to different concentrate-to-roughage diets on ruminal fermentation in vitro. A 4x6 two factorial experimental design (the concentrate-to-roughage ratio, 20:80, 30:70, 40:60, 50:50 and the MOS level, 0, 0.4, 0.8, 1.2, 1.6 and 2.0%) was carried out. The gas production technique was adopted and used the 100 mL cultivated bottles, 50 mL graduated syringes and thermostatic water bath pans as in vitro cultivated device. The in vitro incubation continued 24 h and collected samples at 3, 6, 9, 12 and 24 h. Each treatment executed five replicates at each fermentation time. The results showed the gas and methane production were not impacted by concentrate-to-roughage and MOS and the combination of two factors did not influence all items significantly (p>0.05). The In vitro Dry Matter Digestibility (IVDMD) was impacted by concentrate-to-roughage ratio (20:80<40:60, 9 and 12 h, p<0.05, 24 h, p<0.01; 20:80<50:50, 3, 12 and 24 h, p<0.01). The In vitro Crude Protein Digestibility (IVCPD) was affected by both concentrate-to-roughage ratio (20:80>40:60, 3 h, p<0.05; 20:80>50:50, 12 h, p<0.01; 30:70>40:60, 3 h, p<0.01, 6 h, p<0.05; 30:70>50:50, 3 and 12 h, p<0.01; 6 and 9 h, p<0.05) and MOS (0<1.6%, 24 h, p<0.01; 0<2.0%, 24 h, p<0.05). The pH also influenced by concentrate-to-roughage ratio (50:50<20:80, 3, 6, 9 and 12 h, p<0.01; 50:50<30:70, 3, 6 and 12 h, p<0.01; 50:50<40:60, 12 h, p<0.05; 20:80>40:60, 6 and 12 h, p<0.01; 3 and 9 h, p<0.05) and MOS (0>1.6%, 6 and 12 h, p<0.01; 0>2.0%, 6, 12 and 24 h, p<0.05; 0.4>2.0%, 6 h, p<0.05). The NH3-N content was affected by concentrate-to-roughage ratio (50:50<20:80, 3 and 9 h, p<0.05; 50:50<30:70, 12 h, p<0.01) and MOS (2.0>0%, 24 h, p<0.01). The concentrate-to-roughage impacted the ratio of acetic acid to propionic acid (20:80>50:50, p<0.05), acetic acid to TVFAs (20:80>40:60 and 20:80>50:50, p<0.01) and butyric acid to TVFAs (20:80<40:60 and 20:80<50:50, p<0.05). We could find the IVCPD, pH, NH3-N content increased with the reducing of concentrate approximately while opposite to the IVDMD and the IVCPD and NH3-N content increased with the rising of MOS roughly while opposite to pH.
Zheng Chen, Hao Zhengli, Li Fadi, Guo Yanli and Jin Yanmei, 2012. Effects of Adding Mannan-Oligosaccharide to Different Concentrate-to-Roughage Diets on Ruminal Fermentation in vitro. Journal of Animal and Veterinary Advances, 11: 36-42.