Bioeconomics of Flavobacterium columnare Vaccine Pond Trials with Channel Catfish Ictalurus punctatus

Authors: MALECKI, JILLIAN - Auburn University; ROY, LUKE - Auburn University; ARIAS, COVA - Auburn University; Lange, Miles; Shoemaker, Craig; Beck, Benjamin; TRUONG, NHAT - Auburn University; HANSON, TERRILL - Auburn University

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2021
Publication Date: 4/27/2021
Citation: Malecki, J.K., Roy, L.A., Arias, C.R., Lange, M.D., Shoemaker, C.A., Beck, B.H., Truong, N.T., Hanson, T.R. 2021. Bioeconomics of Flavobacterium columnare Vaccine Pond Trials with Channel Catfish Ictalurus punctatus. North American Journal of Aquaculture. https://doi.org/10.1002/naaq.10191.
DOI: https://doi.org/10.1002/naaq.10191

Interpretive Summary: While Flavobacterium columnare is a well-known fish pathogen that has been studied for over 100 years, columnaris disease remains poorly controlled and in need of improved management solutions for United States catfish producers. Outside of therapeutants, the disease remains relatively unchallenged in the commercial catfish industry. Attempts to improve the management of this disease have led to the development of a live-attenuated genetic group 2 F. columnare vaccine (hereafter 17-23) administered via immersion to fingerling stage Channel Catfish (Ictalurus punctatus). The current study investigated the efficacy of the 17-23 vaccine on Channel Catfish fingerlings versus non-vaccinated (control) fingerlings grown to foodsize fish in earthen ponds. Data were collected from the two treatments (n=5 per treatment) to evaluate impacts on survival, growth, feed conversion, antibody development, and economic benefit. There were no natural outbreaks of columnaris disease observed during the trial and no significant difference in survival of vaccinated versus control fish. The vaccinated fish had significantly elevated antibodies at 4 weeks post-vaccination but not at 12 weeks. Vaccinated fish were significantly larger at harvest (0.78 ± 0.07lbs) than control fish (0.64 ± 0.04lbs), and the feed conversion ratio (FCR) of vaccinated fish (1.35) was significantly better than control fish (2.13). Partial budget analysis demonstrated use of 17-23 vaccinated fingerlings for growout resulted in a net benefit of US $600 per acre. Based on these results, the vaccine appears to show potential economic benefit to producers but should be further substantiated under both research and commercial settings.

Technical Abstract: While Flavobacterium columnare is a well-known fish pathogen that has been studied for over 100 years, columnaris disease remains poorly controlled and in need of improved management solutions for United States catfish producers. Outside of therapeutants, the disease remains relatively unchallenged in the commercial catfish industry. Attempts to improve the management of this disease have led to the development of a live-attenuated genetic group 2 F. columnare vaccine (hereafter 17-23) administered via immersion to fingerling stage Channel Catfish (Ictalurus punctatus). The 17-23 vaccine was confirmed to protect against F. columnare in Channel Catfish fry in previous studies. The current study investigates and compares the efficacy of the 17-23 vaccine on Channel Catfish fingerlings versus non-vaccinated (control) fingerlings grown to foodsize fish in earthen ponds. Data were collected from the two treatments (n=5 per treatment) to evaluate impacts on survival, growth, feed conversion, antibody development, and economic benefit. There were no natural outbreaks of columnaris disease observed during the trial and no significant difference in survival of vaccinated versus control fish (P = 0.7127). Indirect ELISA results determined that the anti-F. columnare 17-23 antibody concentrations were significantly higher in vaccinated fish at 4 weeks post-vaccination (P < 0.05) but not at 12 weeks (P = 0.334). Vaccinated fish had a significantly higher average weight at harvest (357.5 ± 30g) than control fish (289.3 ± 20g) (P = 0.0013), and the feed conversion ratio (FCR) of vaccinated fish (1.35) was significantly better than control fish (2.13) (P < 0.0001). Partial budget analysis of changing production from use of non-vaccinated fingerlings to use of 17-23 vaccinated fingerlings for growout resulted in a net benefit of US $1,443/ha. Based on these results, the vaccine appears to show potential economic benefit to producers but should be further substantiated under both research and commercial settings.