Effects of dietary lipid concentration and a dairy-yeast prebiotic on growth, body composition, and survival of stressed goldfish challenged with Flavobacterium columnare
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Preliminary feeding trials with goldfish Carassius auratus were conducted by using four practical diets with 4% or 10% supplemental poultry fat (PF) and 0% or 2% dairy-yeast prebiotic. Total lipid in the diets ranged from 9.7% to 16.4%, which is higher than the lipid level in most commercial baitfish diets. Aquarium and pool trials were conducted to compare diet effects in the presence or absence of natural foods. In aquaria, weight gain, survival, and feed conversion were similar among diets, but whole-body lipid and dry matter percentages were higher in goldfish that were fed 10% PF diets than in fish receiving 4% PF diets. In pools, weight gain was higher in goldfish that received the 10% PF diets or the 4% PF diet with prebiotic than in fish that were fed the 4% PF diet without prebiotic. Lipid and dry matter were higher in goldfish that were given 10% PF diets than in fish that were given 4% PF diets. The presence of natural foods in pools may partly explain the differences in results between aquaria and pools. Subsequent bacterial challenges with Flavobacterium columnare were conducted separately for fish in pools that received the 4% PF and 10% PF diets. Some groups of fish were stressed prior to exposure. Stressed goldfish that were fed the 4% PF diet with prebiotic had a survival rate similar to that of unstressed fish that were fed the basal or prebiotic diets, but stressed fish that were given the 4% PF diet without prebiotic had lower survival. Unstressed goldfish that received the 10% PF diets had higher survival than stressed fish, but there was no prebiotic effect. Preliminary results indicate that the dairy-yeast prebiotic has some potential to protect stressed goldfish against F. columnare infection, but more studies are needed to determine whether dietary lipid concentration influences the results. American Fisheries Society 2011.
North American Journal of Aquaculture
author list (cited authors)
Lochmann, R. T., Sink, T. D., & Phillips, H.
complete list of authors
Lochmann, RT||Sink, TD||Phillips, H