Evaluation of Replacement Feeds for the Fry Feed Kyowa for Larval Walleyes

摘要

Because Fry Feed Kyowa (FFK) was the standard and the only commercially manufactured starter feed suitable for intensive culture of larval walleyes Sander vitreus, it became imperative to evaluate other commercial feeds after FFK importation to the USA was banned to prevent the spread of bovine spongiform encephalopathy. A project was undertaken at the Rathbun Fish Culture Research Facility (Rathbun), Moravia, Iowa, and Iowa State University (ISU). Ames, using it single-factor experimental design with Lansy and Epac feeds (INVE Aquaculture, Inc., Ogden, Utah) and Gemma feed (Skretting, Vancouver, British Columbia). Walleyes were cultured at both sites front 3 to 28 d posthatch to evaluate the feeds. Performance indicators included presence of feed in gut, gas bladder inflation, survival, total length (mm), weight (mg), growth rate, and incidence of deformities. At both sites, survival was 2.6-3.6 times greater for fish given Gemma than for fish given the INVE feeds: the difference was significant at Rathbun but not at ISU. Length, weight, and growth rate at both sites were also significantly greater for Gemma-fed walleyes than for INVE-fed fish. Weight advantage produced by Gemma was 192% at ISU and 534% at Rathbon. Performance measures of fish given Gemma were similar to those of fish fed FFK in previous years.