Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae029.
An experiment was conducted to determine the effects of betaine on growth performance and intestinal health in rabbits fed diets with different levels of digestible energy. During a 36-d experiment, a total of 144 healthy 35-d-old weaned New Zealand white rabbits with a similar initial body weight (771.05 ± 41.79 g) were randomly distributed to a 2 × 3 factorial arrangement. Experimental treatments consisted of two levels of digestible energy (normal: 10.20 and low: 9.60 MJ/kg) and three levels of betaine (0, 500, and 1,000 mg/kg). Results indicated that rabbits fed the diet with low digestible energy (LDE) had reduced body gain/feed intake on days 1 to 14 and 1 to 36 (P < 0.05), increased the apparent total tract digestibility (ATTD) of neutral detergent fiber, acid detergent fiber (ADF), and n-free extract, and decreased the ATTD of gross energy (GE), crude fiber, and organic matter (OM; P < 0.05). The LDE diet upregulated the gene abundance levels of duodenum junctional adhesion molecule-3 (JAM-3) and downregulated the ileum toll-like receptor 4, myeloid differentiation factor 88, and interleukin-6 (IL-6; P < 0.05). Activities of amylase, lipase, trypsin, and the immunoglobulin M content in the jejunum were decreased in the LDE treatment group (P < 0.05). Dietary betaine supplementation increased the ATTD of GE, dry matter (DM), ADF, and n-free extract by LDE (P < 0.05). The villus height, crypt depth, and goblet cell numbers were decreased, and the villus-crypt ratio was increased in the duodenum (P < 0.05). The gene abundance levels of duodenum IL-2 were downregulated, and the duodenum JAM-2 and JAM-3 were upregulated (P < 0.05). Furthermore, the addition of betaine to the LDE diet increased the ATTD of GE, DM, and OM in rabbits (P < 0.05). Gene abundance levels of ileum IL-6 and duodenum JAM-3 were upregulated (P < 0.05). In summary, LDE diets can reduce the activity of intestinal digestive enzymes and decrease the ATTD of nutrients. However, the addition of betaine to LDE diets improved the intestinal barrier structure and nutrient ATTD in rabbits, with better results when betaine was added at an additive level of 500 mg/kg.
进行了一项实验，以确定甜菜碱对不同可消化能水平日粮喂养的兔子生长性能和肠道健康的影响。在 36 天的实验中，总共 144 只健康的 35 日龄断奶新西兰白兔，体重初始值相似（771.05 ± 41.79 g），随机分为 2×3 因子设计。实验处理包括两种可消化能水平（正常：10.20 和低：9.60 MJ/kg）和三种甜菜碱水平（0、500 和 1000 mg/kg）。结果表明，饲喂低可消化能（LDE）日粮的兔子在第 1 至 14 天和第 1 至 36 天的体重增长/饲料摄入量降低（P＜0.05），增加了中性洗涤纤维、酸性洗涤纤维（ADF）和无氮提取物的表观全肠道消化率（ATTD），降低了总能（GE）、粗纤维和有机物（OM）的 ATTD（P＜0.05）。LDE 日粮上调了十二指肠连接黏附分子-3（JAM-3）的基因丰度水平，下调了回肠 toll 样受体 4、髓样分化因子 88 和白细胞介素 6（IL-6）的基因丰度水平（P＜0.05）。LDE 处理组空肠中淀粉酶、脂肪酶、胰蛋白酶的活性和免疫球蛋白 M 含量降低（P＜0.05）。饲粮添加甜菜碱增加了 LDE 对 GE、干物质（DM）、ADF 和无氮提取物的 ATTD（P＜0.05）。十二指肠绒毛高度、隐窝深度和杯状细胞数量减少，绒毛-隐窝比增加（P＜0.05）。十二指肠 IL-2 的基因丰度水平下调，十二指肠 JAM-2 和 JAM-3 的基因丰度水平上调（P＜0.05）。此外，LDE 日粮添加甜菜碱增加了兔子 GE、DM 和 OM 的 ATTD（P＜0.05）。回肠 IL-6 和十二指肠 JAM-3 的基因丰度水平上调（P＜0.05）。综上所述，LDE 日粮可降低肠道消化酶活性，降低养分 ATTD。然而，LDE 日粮添加甜菜碱可改善兔子的肠道屏障结构和养分 ATTD，甜菜碱添加水平为 500mg/kg 时效果更佳。
