Dietary supplementation of autolysed yeast enhances growth, liver functionality and intestinal morphology in African catfish

A feeding trial was conducted to evaluate the potential of dietary supplementation of autolysed brewer's yeast (AY) on African catfish. The catfish (22.5 ± 1.15 g/fish, 20 fish 33 L/tank) were fed with either of diets (390 g/kg crude protein, 140 g/kg lipid) supplemented with 0, 3, 6 or 10 g/kg AY (n = 3). After 49 days of feeding, the final body weight and metabolic growth rate of the catfish fed 3 g/kg AY (3-AY) diet were higher than those fed the control diet (p <.05). The lowest level (p <.05) of alanine transaminase was detected in the blood of the catfish fed 3-AY diet. The mid-intestinal histology of the catfish revealed no significant difference (p >.05) in intestinal perimeter ratio. However, an elevated (p <.05) abundance of goblet cells and intraepithelial leucocytes were found in the intestine of catfish fed 3, 6 and 10 g/kg AY diets, with the highest level of abundance recorded in the mid-intestine of the catfish fed 3-AY diet. The results suggest that dietary 3 g/kg autolysed brewer's yeast supplementation improves growth performance of African catfish without deleterious effect on liver functionality and gut morphology.