Studies On Measurement And Influcence Factors Of Methane Emission Of Bactrian Camels

In this study, the methane production of Inner Mongolian Bactrian Camels was measured by SF6 tracer technique when were fed on different single pastures. And the effect factors of the methane production of Bactrian camels were studied by deteriming intake,digestibility,rumen ferment index and the relative number of methanogens. The papers divided into two parts. Part one: the methane production of Inner Mongolian Bactrian camels was measured when were fed different on single pastures. Three Inner Mongolia Bactrian Camels in good body conditions were chose as the experimental animals. In ad libitum conditions, the methane production was measured using SF6 tracer technique after they were fed on Corn silage, Sorghum, Wheatgrass, fermented Caragana intermedia, Krascheninnikovia ceratoides Gueldenstaedt. The results showed that the daily methane production of each camel in 5 kinds of tested samples grasses by SF6 tracer technique was:16.23g/KgDMI (fermented Caragana intermedia);27.07g/Kg DMI(Corn straw);18.20g/Kg DMI(Sorghum);21.45g/KgDMI(Krascheninnikovia ceratoides Gueldenstaedt); 21.02g/KgDMI (wheatgrass).Part two: the effect factors of methane production of Bactrian Camels were studied.1.The effects with the methane production of Bactrian Camel was analysed by determining nutrients, feed intake and digestibility of eating grass. The results showed that methane production increasing with the increase in the content of NDF,except for the wheatgrass.The correlation between ruminant methane production and feed intake was negative.Except for the fermentation Caragana The methane production of Bactrian Camel increased with the increasing of forage digestibility.2.By determining fermentation index and polymorphism and the relative number of methane bacteria in rumen inner environment. Furthermore, the effect on methane production was researched.The results showed that:(1) At different time points, the pH value did not significantly affect the rumen methane production in the condition of relative stability. (2) The output of methane per kg dry matter intake was negatively correlated with the concentration of NH3-N in rumen fluid.(3) The dynamic varies of the concentrations of volatile fatty acid in rumen had shown a consistent trend except Krascheninnikovia ceratoides Gueldenstaedt when the Bactrian Camels were fed on different pastures. The concentrations of volatile fatty acid reached the highest when 4h after the morning feeding. Methane output and the ratio of acetic acid and metacetonic acid in rumen was positively correlated.(4) Methane output had a positive correlation with the bacterial protein.(5) With the increase in the number of protozoa methane output was also increasing. (6) By gene sequencing and homology analysis revealed the advantages of different grass flora belong to uncultured bacteria have been studied,and different with known five methanogens, indicating the Bactrian Camel methane producing bacteria are different with cattle and sheep. the homology was from 60.4% to 100.0%. Output of methane was not affected by the difference among bacteria groups. (7) After three kinds of forage were fed, the relative copy number of MCRa gene of total methanogens was not significant difference in per milliliter of rumen fluid at different time points. The relative number of methanogens in the order: corn straw> Carborescens > fermentation Caragana.