Study On Isolation,Characterization And Production Performance Of Ruminal Facultatively Anaerobic Cellulose-Decomposing Bacteria In Holstein Cows

Rumen is a crude fiber’s natural fermentation tank because it has a large number of microbes,80%the coarse fodder of ruminant animals in the rumen was decomposited and used.China was a big agricultural nation,there were a great number of crops straw wasted every year since unreasonal utilization,to improve the utilization rate of crops straw,rumen bacteria had became a hot topic.Facultative anaerobic of rumen became a focus gradually because main cellulose-decomposing bacteria of rumen need higher requirements for the environment.This paper will isolate and identify screen a cellulose-decomposing bacteria of facultative anaerobic,to research the influence on the rumen fermentation and cow milk products in the middle and the milk composition.This test was divided four aspects into as follow:Test1:This experiment was strains of cellulolytic isolated through first screening of selective medium, and then cultured in cellulose congo red medium and corn straw medium to assay cellulose enzyme activity and DMD, R3was the best. Its transparent spot diameter/colony diameter was6.27, CMCase was5.94U/g, FPase was1.12U/g and DMD was23.73%.Test2:Testing by morphological identification, the strains and biochemical identification, growth characteristics and safety of R2, R3, R4, R5and R19. The results showed that strains R2was genus corynebacterium, R3was aeromonas fiber, R5was bacillus, two strains were identified that did not fully meet the number of measured strain tolerance pH value of roughly5.0to10.0, high temperature tolerance was not high,47℃growth was poor, but safety higher except R4.Test3:This experiment using the single factor and iterant experimental design, the experiment selected four holstein cows with permanent rumen fistula and similar body condition. Taking the mixed rumen liquor and adding different doses of R3rumen bacteria culture in vitro. They were: the control group(0cuf/g),the first group(3%adding amount,4.4×108cuf/g),the second group(5%adding amount,7.8×108cuf/g), the third group(10%adding amount,1.2×109cuf/g).Each group set seven time points:2,4,8,12,24,36and48. There were three repeated samples in every point. The results showed that:Adding R3culture could inease DMD, NDFD, ADFD(P<0.01) which were improved by35.41%,48.90%,30.23%in comparison with control group,and could inease BCP, TVFA and acetic acid, CMCase, FPase and utilization ratio of ammonia(P<0.05). The adding3%R3culture effect is best in this test. but had no significant effect on other kinds of acid and the ratio of acetic acid to propionic acid(P>0.05). And then, adding different bacterias culture in vitro. They were:DZ group(substrate),R3group(substrate+R3culture),KC group(substrate+bacillus subtilis culture),DY group(substrate+bacillus licheniformis culture). Each group have same bacterial number(4.4×108cuf/g)and cultivate24h. There were three repeated samples in every group. The results showed that:The group of R3, KC, DY were improved the utilization ratio of ammonia and ineased BCP content, DMD, ADFD, NDFD (P<0.01). they had no significant effect on TVFA, acetic acid, propionic acid, butyric acid and the ratio of acetic acid to propionic acid(P>0.05), but all of them have the rising trend in3treatment groups.Test4:The objective of this paper to determine the effects of feeding R3culture with different levels on the performance of Chinese Holstein dairy cows.15cows with similar weight、parity and milk capacity, adopting randomly assigned to3treatments:contrast group (0cfu/d), the first group (0.75×1011cuf/d) and second group (1.5×1011cuf/d). The experiment lasted for75days, including15days pre-experiment. The results showed that compared with control group milk yield of two experimental group were significantly improved by1.96%、7.31%and4%fat-corrected milk and energy-corrected milk of the second group were significantly improved by12.05%、12.77%(P<0.01) The fat, protein rate and fat, non-fat soild capacity of the second group increased by14.92%、8.97%、6.61%、6.77%respectively (P<0.05) and protein capacity increased by17.73%(P<0.01).In conclusion,in the cows’s rumens a certain number of facultative anaerobic cellulose decompose bacteria. In the results can be drawn, R3(fiber unicellular bacteria category) can improve the cow rumen fermentation, promote in the degradation of rumen cellulose, so as to improve the milk production and milk composition, it is significance for improving cows’ products and has the possibility as microbial additive.