Effects Of Feeding Types And Breeds On Rumen Methanogens And Related Microflora In Inner Mongolia Cashmere Goats

Cashmere goat industry is the main economic growth point in Inner Mongolia.The current breeding mode is mainly based on natural grazing,But feeding on grazing not only affects its production performance,but also produces more methane,resulting in wasted energy.So In this study,Daqingshan and Arbas cashmere goats were selected as the research object,and natural grazing and grazing supplementation were adopted.To analy the ruminal fermentation characteristics,methanogens of quantity and their associated microorganisms and the characteristics of methanogens.The study on the rumen fermentation characteristics of Inner Mongolia cashmere goats showed that:The pH of rumen fluid in the Daqingshan supplement group?RS2group?was 7.19 lower than that in the Daqingshan natural grazing group?RS1 group?,but the difference was not significant?P>0.05?.Under the same grazing conditions,the pH values of rumen fluid in Daqingshan sheep?RS1 group?and Albus?RS3?were 7.46 and7.21,respectively,with no significant difference?P>0.05?.The concentrations of NH₃-N in the three groups were 5.56 mg/dL,10.59 mg/dL,and 5.91 mg/dL,respectively,and RS1and RS2 were significantly different?P<0.01?,while RS1 and RS3 were not significantly different?P>0.05?.The concentrations of acetic acid,propionic acid and butyric acid in the rumen fed Daqingshan cashmere goats were 38.65 mmol/L,13.07 mmol/L and 6.11mmol/L,respectively,which were significantly higher than that of grazing Daqingshan cashmere goats?P<0.05?.The difference of acetic acid/propionic acid was not significant?P>0.05?;There was no significant difference in the acid levels between the RS1 and RS3groups.?P>0.05?.The study on the effects of rumen methanogens and related microbial populations on Inner Mongolia cashmere goats showed that:The amount of rumen methanogens in RS2group was 1.68×10⁸/mL,which was significantly lower than that of RS1 group1.22×10⁹/mL.Under the same grazing conditions,the number of methanogenic bacteria in the RS3 group was 8.04×10⁸/mL,which was not significantly different from that in the RS1 group?P>0.05?.Affected by feed supplement factors The R.albus?F.succinogenes?Rflavefaciens were 1.72×10 ⁹ cells/mL,1.22×10 ⁷ cells/mL,7.33×10 ⁶ cells/mL,respectively.Which were lower the grazing conditions,2.99×10⁹ cells/mL,8.04×10⁷cells/mL,and 1.60×10⁷ cells/mL,but the difference was not significant.The number of rumen protozoa decreased with the addition of concentrate,but there was no significant difference in the number of rumen species.The number of rumen protozoa in RS1,RS2,and RS3 groups was 2.43×10⁶,1.09×10⁶,and 1.51×10⁶,respectively.The study on the effect of rumen methanogens on the structure of ruminal goats in Inner Mongolia cashmere goats showed that:The RS1,RS2,and RS3 groups contained an average of 121,187,and 152 OTUs per sample.The Chaol index and ACE index in the RS2 group were respectively 340 and 340 respectively,which were significantly higher than the RS1 group?224,231?.The effect of supplementary feeding on the structure of methane-producing bacteria in the rumen could change the proportion of methanogens.but the dominant methanogens in the rumen of the three goats belong to the genus Methanobrevibacter.which were 47.34%,58.90%and 43.28%,respectively.RS1 and RS2groups had significant differences?P<0.05?,and RS1 and RS3 had no significant differences?P>0.05?.Methanococcus spp.was the second,which accounted for 5.23%,0.46%,13.40%in the three groups,respectively.The RS3 group was significantly higher than the RS1 group?P<0.01?.Among them,Methanospirillum are endemic to the RS2group,and the Methanoculleusis endemic to the RS1 group,However,the occupancy was very low,0.001%and 0.003%,respectively.Unknown genus occupies a large proportion?39.53%-46.97%?in each group.