Effect of dietary Bacillus pumilus A1_YM_1 on growth, intestinal morphology and some hematological parameters of hybrid catfish (Clarias macrocephalus × Clarias gariepinus)

摘要

A 60 day feeding trial was performed to examine the dietary supplementation of Bacillus pumilus A1_YM_1 (BP) on growth, intestinal morphology and some hematological parameters of hybrid catfish (Clarias macrocephalus × Clarias gariepinus). Fish with an average weight of 8.55±0.18 g were divided into 4 treatments with 3 replications. The control treatment was fed with the basal diets, whereas the experimental treatments were fed the basal diet incorporated with 1×106, 1×107 and 1×108 CFU/g. The results indicated that fish fed the diets supplemented with BP significantly enhanced final weight, weight gain, specific growth rate, average daily gain and feed conversion efficiency when compared to the control diet (P0.05). Hematological evaluation showed supplementation of BP in the fish diets significantly increased red blood cell, white blood cell, lymphocyte and neutrophil when compared to the control diet (P0.05). Histological study of different parts (anterior, middle and posterior) of intestine proper revealed that dietary supplementation of BP significantly enhanced intestinal villi width, intestinal villi height, thicknesses of muscular layers, goblet cell number and microvillus height when compared to the control (P0.05). General feed intake behavior and health as well as feed acceptability of the treatments were the same as the control. It was suggested that the optimum dietary level of BP for catfish cultivation observed was 1×107 CFU/g. Thus, the results of this study support the use of BP in diets as a probiotic in order to enhance growth, intestinal morphology and hematology of catfish.