title: In vitro evaluation on neutral detergent fiber and cellulose digestion by post-ruminal microorganisms in goats.
abstract: BACKGROUND
  Post-ruminal digestion of fiber has received much less attention than its ruminal digestion. Using in vitro incubation techniques, the present study explored whether variations in fiber digestion occurred in different segments of the post-ruminal tract and whether fiber structure could influence its digestibility. A split plot design was conducted with gut segments (jejunum, ileum, cecum and colon) as main plot and substrates (neutral detergent fiber (NDF) and cellulose (CEL)) as subplot.
  
  
  RESULTS
  With the same substrate, the final asymptotic gas volume (V(F)), gas production at t(i) (V(t(i)), digestibility, microbial crude protein (MCP), total bacteria number (TBN), total short-chain fatty acids (TSCFA) and xylanase in incocula from the cecum and colon exceeded (P < 0.01) those in incocula from the jejunum and ileum, while the NH3-N in the former was less (P < 0.01). For the same gut segment, the digestion of CEL was superior to NDF, as reflected in greater V(F), V(t(i)), maximum rate of gas production, digestibility, enzyme activities and SCFA but lower pH and NH3-N.
  
  
  CONCLUSIONS
  The current results imply that the intestinal contents from the cecum and colon have greater potential to digest fiber than those from the jejunum and ileum, and CEL is more easily digested in the post-ruminal tract than NDF.
authors.affiliation: Key Laboratory for Agro-Ecological Processes in Subtropical Region, Hunan Research Center of Livestock and Poultry Sciences, South-Central Experimental Station of Animal Nutrition and Feed Science in Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, Hunan, 410125, China; University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jinzhen
authors.initials: J
authors.lastname: Jiao
authors.forename: Pengpeng
authors.initials: P
authors.lastname: Wang
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: He
authors.forename: Shaoxun
authors.initials: S
authors.lastname: Tang
authors.forename: Chuanshe
authors.initials: C
authors.lastname: Zhou
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Han
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Duanqin
authors.initials: D
authors.lastname: Wu
authors.forename: Jinhe
authors.initials: J
authors.lastname: Kang
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Tan
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D002432:Cecum / Q000378:metabolism / Q000382:microbiology; D002482:Cellulose / Q000378:metabolism*; D003106:Colon / Q000378:metabolism / Q000382:microbiology; D003902:Detergents; D004043:Dietary Fiber / Q000378:metabolism*; D004063:Digestion; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005740:Gases / Q000378:metabolism; D006041:Goats / Q000378:metabolism* / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D007082:Ileum / Q000378:metabolism / Q000382:microbiology; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000382:microbiology; D007583:Jejunum / Q000378:metabolism / Q000382:microbiology; D012417:Rumen; D014995:Xylosidases / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D005740:Gases; D000641:Ammonia; D002482:Cellulose; D014995:Xylosidases
keywords: digestion; fiber; goat; in vitro; post-ruminal tract