|Title||Quantitative feed restriction rather than caloric restriction modulates the immune response of growing rabbits.|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Knudsen, C, Combes, S, Briens, C, Duperray, J, Rebours, G, Salaun, J-M, Travel, A, Weissman, D, Gidenne, T, Oswald, IP|
|Date Published||2015 Mar|
|Keywords||Animal Feed, Animals, Body Weight, Caloric Restriction, Diet, Energy Intake, Female, Ileum, Immunity, Immunoglobulin A, Immunoglobulin G, Interleukin-1beta, Interleukin-2, Male, Ovalbumin, Rabbits, Spleen, Tumor Necrosis Factor-alpha, Weaning|
BACKGROUND: Short-term feed restriction strategies are used in rabbits to reduce postweaning digestive disorders, but little is known about the involvement of the immune system in these beneficial effects.OBJECTIVE: In the present study, the consequences of feed and energy restriction on immune response were investigated.METHODS: At weaning, 320 male and female rabbits were assigned to 4 groups differing in dietary digestible energy (DE) concentrations and intake levels: a low-energy ad libitum-feed (LE100) group, a low-energy restricted-feed (LE75) group, a high-energy ad libitum-feed (HE100) group, and a high-energy restricted-feed (HE75) group. The high-energy groups consumed 10.13 MJ DE/kg of feed, whereas the low-energy groups consumed 9.08 MJ DE/kg (formulated values). Intake amounts for the restricted groups were 75% those of the ad libitum groups. Rabbits consumed these diets until age 63 d, after which they consumed feed ad libitum for 9 d. Ten rabbits per group and per age were killed at ages 42, 50, 63, and 72 d. Spleens and appendixes were weighed; Peyer's patch surface area was determined by image analysis; plasma total immunoglobulin (Ig) G and anti-ovalbumin IgG; and fecal and plasma IgA concentrations were determined by ELISA; and ileal expressions of cytokines were measured by quantitative reverse transcriptase-polymerase chain reaction at ages 50 and 63 d.RESULTS: The relative weight and size of the lymphoid organs were not affected by treatments. Concentrations of plasma total IgA (-41% at 63 d and -29% at 72 d), IgG (-22% at 72 d), and anti-ovalbumin IgG (-41% at 63 d) were lower with feed restriction. Fecal IgA concentrations were lower with quantitative restriction (-40%, -52%, and -65% at age 42, 50, and 63 d, respectively) and energy restriction (-56%, -46%, and -73% at ages 50, 63, and 72 d, respectively). Feed-restricted rabbits tended to have greater expressions of interleukin (IL) 1β and IL-2 and lower expressions of tumor necrosis factor α (P < 0.1).CONCLUSION: These results demonstrated that, in rabbits, restriction and, to a lesser extent, dietary energy concentration modulate gut immunity.
|Alternate Journal||J. Nutr.|