Effect of dietary supplements in American bullfrogs reared in low and high stocking densities

摘要: Abstract The aim of this study was to evaluate the effect probiotic Bacillus subtillis and beta-glucan from fungus Agaricus blazei on survival, growth immunological capacity in bullfrogs ( Lithobates catesbeianus) cultured low high stocking densities. Animals weighing 24.3 ± 2.38 g were randomly distributed into four treatments with simultaneous replicates: D100: 100 frogs/m 2 (control); D236: 236 ; D236 + Prob.: supplemented probiotic; D236 + BG: beta-glucan. parameters evaluated weight gain, plasma corticosterone (CORT), phagocytic (PC) index (PI), at 24 h 15 30 days. There is significant interaction between time for CORT levels. At 30 days, these values very close D100 (control) D236 + BG groups. Meanwhile, no statistical differences observed PC PI. These results indicate that reduced effects stress caused by density bullfrogs, but did not reduce effects. Both compounds are efficient increasing survival rates, gain neither immune response animals. Thus, use commercial food additives may have favorable impact desired farmer. Their aquaculture should be further studied experiments involving a longer trial period taking account cost their use.