Departamento de Producción Agraria, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, Madrid, Spain.
Carrera de Medicina Veterinaria y Zootecnia, Universidad Nacional de Loja, Ciudad Universitaria La Argelia, Loja, Ecuador.
J Anim Sci. 2018 May 4;96(5):1806-1817. doi: 10.1093/jas/sky106.
The aim of this study was to examine whether the combination of dietary soluble fiber and cellobiose exerts a synergistic effect on growth performance, health status, fermentation traits, and immune response in rabbits. Six treatments in a 3 × 2 factorial arrangement were used: 3 cellobiose concentrations in drinking water (0.0, 7.5, and 15.0 g/L) × 2 dietary levels of soluble fiber (84.0 and 130 g/kg DM, for the low soluble fiber [LSF] and high soluble fiber [HSF] diets, respectively). A total of 318 young rabbits (53/treatment) were weaned at 34 d of age and had ad libitum access to feed and water. At 46 d of age, 9 rabbits/treatment were slaughtered and ileal and cecal digesta were collected to analyze VFA profile and the immune response in the cecal appendix mucosa. At 48 d of age, the cellobiose supplementation was withdrawn and the experimental diets were replaced by a standard commercial diet until 61 d of age. From 34 to 48 d of age, there was a linear increase of mortality with the level of cellobiose in the HSF group (0% vs. 17.1%; P = 0.017). In contrast, a quadratic effect of cellobiose level on mortality was observed in the LSF group, the rabbits offered 7.5-cellobiose showing the lowest mortality (5.7% vs. 21.4%; P = 0.030). Cellobiose level had a quadratic effect on ADFI, ADG, and G:F in this period (P ≤ 0.047), with the 7.5-cellobiose groups having the best growth performance. In contrast, only minor changes on these traits were observed from 48 d of age onwards. Cellobiose level influenced quadratically the ileal VFA concentrations (P = 0.014), showing the maximal value in the 7.5-cellobiose groups. In rabbits fed 7.5-cellobiose-LSF, a change of acetate to propionate, butyrate, and valerate was observed in the ileum. Increasing cellobiose levels reduced linearly cecal VFA concentrations in HSF fed rabbits, but no effect was detected in LSF groups (P = 0.046). The level of soluble fiber increased VFA concentrations in both the ileum (by 22%; P < 0.001), and the cecum (by 11%; P = 0.005). The relative gene expression of IL-6, IL-10, TNF-α, iNOS, MUC-1, and toll-like receptors (TLR-2 and TLR-4) in the cecal appendix increased linear and quadratically with increasing levels of cellobiose (P ≤ 0.063). In conclusion, in rabbits fed LSF diets, a dose of 7.5 g cellobiose/L drinking water would be recommended, whereas these levels of cellobiose supplementation should be avoided in rabbits fed HSF diets.
本研究旨在探讨膳食纤维与纤维二糖的组合对兔子生长性能、健康状况、发酵特性和免疫反应的协同作用。采用 3×2 因子设计，共设置 6 种处理方式：饮水（0.0、7.5 和 15.0 g/L）中 3 种纤维二糖浓度×2 种膳食纤维水平（低膳食纤维[LSF]和高膳食纤维[HSF]饲料，分别为 84.0 和 130 g/kg DM）。共有 318 只幼兔（53 只/处理）在 34 日龄断奶，自由采食和饮水。在 46 日龄时，每组 9 只兔子被屠宰，采集回肠和盲肠内容物，分析 VFA 谱和盲肠阑尾黏膜的免疫反应。在 48 日龄时，停止纤维二糖补充，用标准商业饲料替代实验饲料，直至 61 日龄。从 34 日龄到 48 日龄，HSF 组死亡率随纤维二糖水平线性增加（0%比 17.1%；P = 0.017）。相比之下，LSF 组纤维二糖水平对死亡率的影响呈二次曲线，添加 7.5 g/L 纤维二糖的兔子死亡率最低（5.7%比 21.4%；P = 0.030）。在这段时间内，纤维二糖水平对 ADFI、ADG 和 G:F 呈二次影响（P≤0.047），添加 7.5 g/L 纤维二糖的兔子生长性能最好。相反，48 日龄以后这些特征仅出现较小的变化。纤维二糖水平对回肠 VFA 浓度呈二次影响（P = 0.014），在添加 7.5 g/L 纤维二糖的组中，VFA 浓度最高。在接受 7.5 g/L 纤维二糖和 LSF 的兔子中，观察到乙酸到丙酸、丁酸和戊酸在回肠中的变化。在 HSF 喂养的兔子中，随着纤维二糖水平的增加，盲肠 VFA 浓度呈线性下降，但 LSF 组未检测到这种影响（P = 0.046）。膳食纤维水平增加了回肠（增加 22%；P<0.001）和盲肠（增加 11%；P = 0.005）中 VFA 的浓度。盲肠阑尾中 IL-6、IL-10、TNF-α、iNOS、MUC-1 和 toll 样受体（TLR-2 和 TLR-4）的相对基因表达随纤维二糖水平的增加呈线性和二次增加（P≤0.063）。综上所述，在 LSF 饮食中，建议添加 7.5 g/L 的纤维二糖，但在 HSF 饮食中应避免添加这些水平的纤维二糖。
