This study was conducted to evaluate the prebiotic action of distinct linseed fibers on diets for silver catfish (Rhamdia quelen) juvenile. For this, soluble and insoluble fractions of linseed fiber were concentrated separately and combined in four ratios (1:0.5, 1:1, 1:2, 1:4), which were added in diets and evaluated along with a control diet. After 45 days receiving the experimental diets, the animals were submitted to biometry for data collection and samples. The experimental design was completely randomized, data were submitted to analysis of variance, and the means were compared by Tukey’s test (P < 0.05). Fish performance was higher for the group that received the 1:2 and 1:4 diets. The production of intestinal acetic acid was higher in fish fed on the 1:2 diet, and butyric acid was higher with 1:4 diet and the propionic acid with the control diet. The control diet led to lower counts of goblet cells. Total proteins and globulins in plasma, mucoprotein, total immunoglobulins, and cutaneous mucus pH were higher in fish fed on diets 1:2 and 1:4. Cortisol levels and intestinal pH were lower in these treatments. The linseed fiber intake increased total plasma immunoglobulins and plasma alkaline phosphatase activity and in mucus. It was concluded that the use of 1:2 and 1:4 soluble fiber/insoluble linseed in the diet beneficially modulates the production of short-chain fatty acids in the digesta, with reflection on growth performance, number of goblet cells in the intestinal epithelium, and improvement in plasma and skin mucus parameters of fish.

进行这项研究以评估不同亚麻籽纤维对银cat鱼（Rhamdia quelen）幼鱼日粮的益生元作用。为此，将亚麻籽纤维的可溶部分和不溶部分分别浓缩，并以四个比例（1：0.5、1：1、1：2、1：4）合并，将其添加到日粮中并与对照日粮一起进行评估。接受实验饮食45天后，将动物接受生物测定以收集数据和样品。实验设计完全随机化，将数据提交给方差分析，并通过Tukey检验比较均值（P <0.05）。接受1：2和1：4饮食的组的鱼类生产性能更高。以1：2饲喂的鱼的肠乙酸产量更高，以1：4饲喂的鱼丁酸含量较高，而以对照饮食饲喂的丙酸含量更高。对照饮食导致杯状细胞数量减少。以1：2和1：4喂养的鱼的血浆，粘蛋白，总免疫球蛋白和皮肤粘液pH中的总蛋白和球蛋白较高。在这些治疗中，皮质醇水平和肠道pH较低。亚麻籽纤维的摄入量增加了血浆总免疫球蛋白和血浆碱性磷酸酶的活性，并增加了粘液的含量。结论是，饮食中使用1：2和1：4可溶性纤维/不溶亚麻籽有利地调节了消化物中短链脂肪酸的产生，反映了其生长性能，