丁酸梭菌对七彩神仙鱼生长、形体指标、营养利用和肠道结构功能的影响

为探讨丁酸梭菌(Clostridium butyricum)对七彩神仙鱼(Symphysodon haraldi)生长、形体指标、营养利用和肠道结构功能的影响，在基础饵料中分别添加0(对照)、1×104、1×105、1×106、1×107、1×108 cfu/g丁酸梭菌饲养幼鱼8周。结果显示，与对照组相比，丁酸梭菌对七彩神仙鱼生长和形体指标无显著影响。1×105 cfu/g添加组鱼体粗蛋白含量增加，对蛋白质的消化率显著提高。丁酸梭菌显著提高了中肠肠道绒毛高度和宽度，且1×105 cfu/g添加组肠道酸性黏多糖分泌量显著增加。对于肠道消化酶和抗氧化能力，1×105 cfu/g添加组胰蛋白酶活性显著提高，1×106 cfu/g添加组丙二醛含量显著降低。肠道内容物短链脂肪酸分析显示，1×105 cfu/g添加组的乙酸和丙酸含量显著高于对照组，且总酸含量在该添加组达到最大显著高于其他组。研究表明，在本试验条件下，七彩神仙鱼饵料中添加1×105 cfu/g丁酸梭菌可以改善肠道结构，提高肠道消化和抗氧化能力，增加肠道短链脂肪酸的分泌和营养利用率。

Effects of Clostridium butyricum on growth, body index, nutrient utilization, and intestinal structure and function of discus fish Symphysodon haraldi

To determine the effects of Clostridium butyricum on growth, body index, nutrient utilization, and intestinal structure and function, C. butyricum was added in basic feed for discus fish Symphysodon haraldi with concentration of 0 (control)、1×104、1×105、1×106、1×107 and 1×108 cfu/g, respectively. After 8-week culture, no significant difference was showed on growth and body index of fish in C. butyricum-added group. However, crude protein content and digestibility in 1×105 cfu/g addition group increased significantly. Compared to control one, height and width of midgut villi in fish fed with C. butyricum was apparently increased and mucopolysaccharide secretion level of fish in 1×105 cfu/g addition group significantly improved. For intestinal digestive and antioxidant enzymes, the trypsin activity of fish in 1×105 cfu/g addition group was greatly improved. Furthermore, the malondialdehyde content in 1×106 cfu/g addition group fish was significantly decreased. Short chain fatty acids (SCFAs) were measured in fish intestinal contents, it suggested that acetic acid and propionic acid in 1×105 cfu/g addition group was significantly higher than that in the control group, and the total acid content reached the maximum in this addition group, which was significantly higher than other groups. Studies have shown that under the conditions of this experiment, adding 1×105 cfu/g C. butyricum to the discus fish bait can improve intestinal structure, improve intestinal digestion and antioxidant capacity, and increase intestinal SCFAs secretion and nutrition utilization.