Study On Response Pattern Of Gut Microflora Of Goose To Dietary Fiber And Its Function

The goose, as one of poultry, is capable of utilizing a large amount of fiber. Clarifying the mechanism for digesting crude fiber(CF) in goose is of great significance on the utilization of roughage resource. In the present study, response pattern of gut microflora of goose to different levels and sources of dietary fiber, isolated and screening of cellulose decomposing bacteria and their best combinations were studied using methods of molecular microbial ecology, animal nutrition and biology. The results will provide reference for fully understanding mechanism for digesting crude fiber in goose.One hundred and eighty healthy Carlos geese with 35 days old(half male and half female)were divided into 4 groups(n=45) with 3 duplicates, and then fed with diets containing 5% or 8%crude fiber using alfalfa or corn stover as the CF sources, irrespectively. After feeding 42 days,nutrients digestibility, activity of digestive enzymes in intestines, blood biochemical indexes and intestinal microflora were determined using digestion and metabolism experiment, slaughter experiment and MiSeq PE300 sequencing platform, furthermore, isolated and screening of cellulose decomposing bacteria and their best combinations were carried out. The results are as following.1. Increasing dietary fiber level could significantly enhance feed intake, digestibility of NDF and ADF, thymus index, burse index, spleen index and activity of cellulose enzyme and trypsin in ileum and cecum. Digestibility of crude protein(CP) was not affected by dietary fiber level. Different fiber source and levels led to the significant difference on digestibility of CP, CF,NDF and ADF. At 5% CF, activity of protein enzymes and alkaline phosphatase levels in corn stover group were significantly higher than alfalfa group, while thymus index was lower. At 8%CF, thymus index and cellulase activity in jejunum in alfalfa group was lower than corn stover group, while cellulase activity in ileum and cecum was higher.2. For the two fiber source, increasing dietary fiber level both could increase bacteria diversity index. In duodenum, increasing dietary fiber level could increase abundance of Lactobacillus, Pediococcus, Ruminococcus and Anaerobiospirillum,and decrease abundance of Pseudomonas, Escherichia, Phyllobacterium, Rhodococcus, Streptococcus, Acinetobacter and Shewanella. In ileum, abundance of Helicobacter, Stenotrophomonas and Brevundimonas decreased, while abundance of Swaminathania increased. In ileum, abundance of Lactobacillus,Clostridium, Ruminococcus and Pseudonocardia significantly increased,while abundance of Enterococcus decreased. In cecum, abundance of Prevotella, Helicobacter and Mucispirillum increased,while abundance of Methanobrevibacter decreased.3. Intestinal microflora of goose was affected by dietary fiber source. Bacteria diversity index of ileum in alfalfa group was significantly higher than corn stover group, while bacteriophyta quantity of abundance above 0.01% in duodenum, jejunum and caecum was lower.These results indicated that alfalfa as fiber source could significantly increase type of bacteria inintestine of goose.4. Twenty-nine cellulose decomposing bacteria strains including 19 aerobic strains and 10 facultative anaerobe strains were isolated from intestines of goose. Eight strains with higher ability of decomposing cellulose were identified as Paenibacillus mucilaginosus, Bacillus subtilis, Clostridium, Bacillus licheniformis, Bacillus cereus, Clostridium cellulolyticum, hemolytic staphylococcus and pseudomonas aeruginosa. The best combination for producing cellulose was cerea bacillus and Pseudomonas aeruginosa.