title: Effects of energy and protein restriction, followed by nutritional recovery on morphological development of the gastrointestinal tract of weaned kids.
abstract: Effects of energy, protein, or both energy and protein restriction on gastrointestinal morphological development were investigated in 60 Liuyang Black kids, which were sourced from local farms and weaned at 28 d of age. Weaned kids were randomly assigned to receive 1 of 4 dietary treatments (15 kids per treatment), which consisted of adequate nutrient supply (CON), energy restriction (ER), protein restriction (PR), or energy and protein restriction (EPR). The entire experiment included adaptation period (0 to 6 d), nutritional restriction period (7 to 48 d), and recovery period (49 to 111 d). Three kids from each group were killed at d 48 and 111, and the rumen, duodenum, jejunum, and ileum were harvested. On d 48 (end of nutritional restriction), lengths of the duodenum (P = 0.005), jejunum (P = 0.003), and ileum (P = 0.003), and weights of the rumen (P = 0.004), duodenum (P = 0.006), jejunum (P = 0.006), and ileum (P = 0.004) of kids in ER, PR, and EPR were less than those of kids in CON. Compared with CON, PR decreased papillae width (P = 0.03) and surface area (P = 0.05) of the rumen epithelium, villus surface area (P = 0.05), and N concentration (P = 0.02) of the jejunum mucosa on d 48. Compared with CON, EPR decreased papillae height (P = 0.001), width (P = 0.001), and surface area (P = 0.003), N concentration (P = 0.01), and the ratio of N to DNA (P = 0.03) of the rumen epithelium. Compared with CON, EPR also decreased villus height (P = 0.01), width (P = 0.006), and surface area (P = 0.006), N concentration (P < 0.001), and the ratio of N to DNA (P < 0.001) of the jejunum mucosa on d 48. On d 111 (end of nutritional recovery), lengths of the duodenum (P = 0.001), jejunum (P = 0.001), and ileum (P = 0.001), weights of the rumen (P < 0.001), duodenum (P = 0.001), jejunum (P < 0.001), and ileum (P < 0.001) of kids in ER, PR, and EPR were still less than those of kids in CON; N concentrations of rumen epithelium of kids in PR (P = 0.01) and EPR (P = 0.001), and the ratio of N to DNA of jejunum mucosa of kids in EPR (P < 0.001) were greater than those of kids in CON. Results indicate that nutritional restriction of 6 wk can retard gastrointestinal morphological development for kids weaned at 28 d of age and retarded development remains evident, even after nutritional recovery of 9 wk.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, The Chinese Academy of Sciences, Changsha PO Box 10, Hunan 410125, PR China.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Sun
authors.forename: Z X
authors.initials: ZX
authors.lastname: He
authors.forename: Q L
authors.initials: QL
authors.lastname: Zhang
authors.forename: Z L
authors.initials: ZL
authors.lastname: Tan
authors.forename: X F
authors.initials: XF
authors.lastname: Han
authors.forename: S X
authors.initials: SX
authors.lastname: Tang
authors.forename: C S
authors.initials: CS
authors.lastname: Zhou
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: Q X
authors.initials: QX
authors.lastname: Yan
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D018753:Diet, Protein-Restricted; D004044:Dietary Proteins / Q000378:metabolism; D002149:Energy Intake; D006041:Goats / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D007421:Intestine, Small / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development; D009929:Organ Size; D011897:Random Allocation; D012417:Rumen / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development; D014886:Weaning
chemical_list: D004044:Dietary Proteins