Study On Establishing Of Methane Production Prediction Models On Bactrian Camels And Inhibitor Of Methane Mession In Vitro

This study was to predict methane production of Bactrian Camels, establish model of predicting methane production and study on the methods for decreasing methane production, the study was divided into two parts.Part one: Methane production of Bactrian Camels was predicted, models for predicting methane production were estabilished and the relationship between methane production and rumen microbe was studied. One mature Bactrian Camels with permanent ruminal cannula was used for donor of rumen liquid, methane production of camel favorite pastures which were picked from Inner Mongolia desert grassland were determined by in vitro method, methane production in vivo were calibrated by formula. Relationship between methane production and rumen microbe were studied. Results showed that: (1)The methane production of Bactrian Camels in growing , grain-filling and maturing were 295.87～502.09g/d, 316.94～713.75g/d and 213.74～340.26g/d respectively. (2) Regression models between methane production and ingredients of pastures were established: a)CH4(g/kgDM)=36.47-0.25NFE(%)+0.26NDF(%)-0.90CP(%) R2=0.824 (p<0.01); b)CH4(g/kgDM)=49.88-0.04Hemi(%)-1.06CP(%)+0.20Cel(%)-0.462NFE(%) R2=0.781(p<0.01).(3)Methane production could be influenced by the ruminal cellulose-decomposed bacteria and methanogen; the positive correlation between cellulose-decomposed bacteria and methanogen counting was found.Part two: The effects of yeast culture and alfalfa saponin on methane production and ruminal fermentation were studied in vitro. Diluted ruminal fluid was incubated anaerobically at 39℃for 24h with or without yeast culture and alfalfa saponin, using diet as substrate. the yeast culture and alfalfa saponin were added at various concentration (yeast culture 1.5%,2.0%,2.5% and 3.0% and alfalfa saponin 0.5%,1.0%,2.0%,4.0%). Results showed that: (1) As the concentrate of yeast culture increased from 2.0% to 2.5%, the methane production decreased by 5.1%-11.0%. pH of the medium was decreased slightly. Gas production, NH3-N and disappearance of DM were increased slightly. TVFA was increased prominently (p<0.05), and molar proportion of acetate decreased and propionate increased with a corresponding decreased in acetate: propionate ratio. Bacteria and cellulose-decomposed bacteria counting increased and methanogen counting decreased with corresponding increased in cellulose-decomposed bacteria ratio and decreased in methanogen ratio. (2) As the concentrate of alfalfa saponin increased from 1.0% to 2.0%, methane production decreased by 9.3-10.1%. pH of the medium was prominently increased. Gas production, NH3-N and disappearance of DM were slightly decreased. TVFA was increased prominently (p<0.05), and molar proportion of acetate decreased and propionate increased with a corresponding decreased in acetate: propionate ratio. Cellulose-decomposed bacteria and methanogen counting decreased, but the effect of alfalfa saponin on methanogen counting was more than on cellulose-decomposed bacteria counting. In conclusion, yeast culture and alfalfa saponin stimulated the mixed ruminal microorganism fermentations as well as to inhibit methane production in vitro.