title: Rumen development process in goats as affected by supplemental feeding v. grazing: age-related anatomic development, functional achievement and microbial colonisation.
abstract: The aim of the present study was to describe age-related changes in anatomic, functional and microbial variables during the rumen development process, as affected by the feeding system (supplemental feeding v. grazing), in goats. Goats were slaughtered at seven time points that were selected to reflect the non-rumination (0, 7 and 14 d), transition (28 and 42 d) and rumination (56 and 70 d) phases of rumen development. Total volatile fatty acid (TVFA) concentration (P= 0·002), liquid-associated bacterial and archaeal copy numbers (P< 0·01) were greater for supplemental feeding v. grazing, while rumen pH (P< 0·001), acetate molar proportion (P= 0·003) and solid-associated microbial copy numbers (P< 0·05) were less. Rumen papillae length (P= 0·097) and extracellular (P= 0·093) and total (P= 0·073) protease activity potentials in supplemented goats tended to be greater than those in grazing goats. Furthermore, from 0 to 70 d, irrespective of the feeding system, rumen weight, rumen wall thickness, rumen papillae length and area, TVFA concentration, xylanase, carboxymethylcellulase activity potentials, and microbial copy numbers increased (P< 0·01) with age, while the greatest amylase and protease activity potentials occurred at 28 d. Most anatomic and functional variables evolved progressively from 14 to 42 d, while microbial colonisation was fastest from birth to 28 d. These outcomes suggest that the supplemental feeding system is more effective in promoting rumen development than the grazing system; in addition, for both the feeding systems, microbial colonisation in the rumen is achieved at 1 month, functional achievement at 2 months, and anatomic development after 2 months.
authors.affiliation: Key Laboratory of Agro-Ecological Processes in Subtropical Region, South-Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences,Changsha, Hunan410125,People's Republic of China.
authors.forename: Jinzhen
authors.initials: J
authors.lastname: Jiao
authors.affiliation: Key Laboratory of Agro-Ecological Processes in Subtropical Region, South-Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences,Changsha, Hunan410125,People's Republic of China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Li
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada,Lethbridge, Alberta,CanadaT1J 4B1.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Beauchemin
authors.affiliation: Key Laboratory of Agro-Ecological Processes in Subtropical Region, South-Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences,Changsha, Hunan410125,People's Republic of China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Tan
authors.affiliation: Key Laboratory of Agro-Ecological Processes in Subtropical Region, South-Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences,Changsha, Hunan410125,People's Republic of China.
authors.forename: Shaoxun
authors.initials: S
authors.lastname: Tang
authors.affiliation: Key Laboratory of Agro-Ecological Processes in Subtropical Region, South-Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences,Changsha, Hunan410125,People's Republic of China.
authors.forename: Chuanshe
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000681:Amylases / Q000096:biosynthesis; D000821:Animal Feed; D000818:Animals; D000831:Animals, Newborn; D002480:Cellulase / Q000096:biosynthesis; D002681:China; D004032:Diet / Q000662:veterinary*; D005248:Feeding Methods / Q000662:veterinary*; D005260:Female; D005285:Fermentation; D005753:Gastric Mucosa / Q000201:enzymology / Q000254:growth & development* / Q000382:microbiology / Q000502:physiology; D005766:Gastrointestinal Contents / Q000737:chemistry / Q000382:microbiology; D006041:Goats / Q000254:growth & development* / Q000382:microbiology / Q000502:physiology; D060434:Herbivory; D008297:Male; D008892:Milk; D010447:Peptide Hydrolases / Q000096:biosynthesis; D012417:Rumen / Q000201:enzymology / Q000254:growth & development* / Q000382:microbiology / Q000502:physiology; D014886:Weaning; D015430:Weight Gain; D014995:Xylosidases / Q000096:biosynthesis
chemical_list: D000681:Amylases; D014995:Xylosidases; D002480:Cellulase; C019826:carboxymethylcellulase; D010447:Peptide Hydrolases
keywords: Microbial colonisation