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; Beck, Benjamin; TRUONG, NHAT TRIET - 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., Arias, C.R., Lange, M.D., Beck, B.H., Truong, N., Hanson, T.R. 2021. Bioeconomics of Flavobacterium columnare vaccine pond trials with channel catfish Ictalurus punctatus. North American Journal of Aquaculture. 83: 207-217. https://doi.org/10.1002/naaq.10191.
DOI: https://doi.org/10.1002/naaq.10191

Interpretive Summary: A pond trial was conducted with channel catfish vaccinated with a live-attenuated columnaris (hereafter termed 17-23) vaccine and control non-vaccinated fish. Data were collected to evaluate the effect of the vaccine on survival, growth, feed conversion, antibody development, and overall economic benefit. The trials were a follow-up to promising laboratory results, which confirmed that the genetic group 2 vaccine increased protection against F. columnare in channel catfish fry. Pond trials using catfish fingerlings represent the commercial catfish environment that use earthen ponds. Monthly sampling to track growth was performed. Blood serum samples were collected and assayed at 4- and 12-weeks post-vaccination. F. columnare strain 17-23 specific antibodies were detected by ELISA (enzyme-linked immunosorbent assay). Results showed no significant increase in survival of vaccinated fish compared to control fish (P = 0.7127), since there were no apparent natural outbreaks of columnaris disease observed during the pond trials. However, ELISA results determined that the antibody concentrations were significantly higher in vaccinated fish 4 weeks post-vaccination, but not at 12 weeks. Vaccinated fish (357.5 g) had a significantly higher average weight at harvest than control fish (289.3), and the FCR of vaccinated fish (1.35) was significantly lower than control fish (2.13). The total amount of feed decreased from the control to vaccinated treatment by 14% but was not significant. Partial budget analysis based on these results from research ponds showed an additional benefit of US$1,482/ha and could be beneficial to commercial producers.

Technical Abstract: A pond trial was conducted with channel catfish (Ictalurus punctatus) vaccinated with a live-attenuated COL vaccine and control non-vaccinated fish. Data were collected to evaluate the effect of the COL vaccine on survival, growth, feed conversion, antibody development , and overall economic benefit. The trials were a follow-up to promising laboratory results, which confirmed that the genetic group 2 (hereafter 17-23) vaccine increased protection against F. columnare in channel catfish fry. Pond trials using catfish fingerlings represent the commercial catfish environment that use earthen ponds. Monthly sampling to track growth was performed from May to October 2019. Blood serum samples were collected and assayed at 4- and 12-weeks post-vaccination. F. columnare strain 17-23 specific IgM antibodies were detected by an indirect ELISA (enzyme-linked immunosorbent assay).. Results showed no significant increase in survival of vaccinated fish compared to control fish (P = 0.7127), and there were no apparent natural outbreaks of columnaris disease observed during the trials. Indirect ELISA results determined that the anti-F. columnare 17-23 antibody concentrations were significantly higher in vaccinated fish 4 weeks post-vaccination (P < 0.05), but not at 12 weeks(P=0.334). Vaccinated fish (357.5 ± 30g) had a significantly higher average weight at harvest than control fish (289.3 ± 20g) (P =0.0013), and the FCR of vaccinated fish (1.35) was significantly lower than control fish (2.13) (P < 0.0001). The total amount of feed decreased from the control to vaccinated treatment by 14% but was not significant (P = 0.1195). Partial budget analysis based on these results from research ponds showed an additional benefit of US$1,482/ha and could be beneficial to commercial producers.