ARS | Publication request: Feeding Lactobacillus spp. and Bacillus spp. Does Not Improve Growth or Survival of Channel Catfish Experimentally Challenged with Edwardsiella ictaluri

Submitted to: American Society of Animal Science Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2010
Publication Date: July 1, 2010
Citation: Peterson, B.C., Wood, M.L., Booth, N.J., Morgan, N., Tellez, G., Hargis, B.M. 2010. Feeding Lactobacillus spp. and Bacillus spp. Does Not Improve Growth or Survival of Channel Catfish Experimentally Challenged with Edwardsiella ictaluri. American Society of Animal Science Annual Meeting.

Technical Abstract: A major problem in the channel catfish industry has been high disease loss to enteric septicemia of catfish, caused by the bacterium Edwardsiella ictaluri. Feeding probiotics may prove beneficial in improving disease resistance. The first study examined the effects of a Lactobacillus probiotic (FloraMax-B11; Ivesco, LLC, Springdale, AR) (poultry origin) on growth and resistance to E. ictaluri. Two hundred catfish (23.5 ± 0.3 g) were assigned to 2 treatments with 5 replicates each: 1.) Control (36% CP diet) and 2.) FloraMax-B11 (11 Lactobacillus spp., sprayed on feed at 106 cfu/g of diet). The fish were fed for 6 wks and then experimentally challenged with E. ictaluri. The second study examined the effects of 3 spores of Bacillus spp. on growth and disease resistance. Bacillus subtilis-1 (environmental sample) and B. subtilis-2 (catfish origin) were previously shown to have antibacterial in vitro activity against Escherichia coli and E. ictaluri. Bacillus pumilus of catfish origin, which did not show in vitro antibacterial activity, was also tested in this study. Five hundred catfish (11.2 ± 0.1 g) were assigned to 4 treatments with 5 replicates each: 1) Control (36% CP diet); 2) BS-1 (B. subtilis at 107 cfu/g of diet); 3) BS-2 (B. subtilis at 107 cfu/g of diet); and 4) BP (B. pumilus at 106 cfu/g of diet). Fish were fed for 9 wks and challenged with E. ictaluri. Data were subjected to ANOVA with tank as the experimental unit. Addition of Lactobacillus spp. and Bacillus spp. to the diet of catfish had no effect on weight gain, FE, or survival after challenge with E. ictaluri (P > 0.10). The results of these studies suggest that neither the Lactobacillus based probiotic nor any of the 3 spore base probiotic candidates improved growth performance or resistance against E. ictaluri . Identifying other catfish specific bacteria and understanding how they may manipulate the microflora of the GI tract will be key in determining whether probiotics have a benefit in improving catfish aquaculture.