Development of Rations for the Enhanced Survival of Salmon. Annual Report

摘要

It is believed that hatchery feed nutritional quality plays an important role in determining the health and ''fitness'' of smolts. Commercial fish meal, the major source of protein in salmon rations, is subject to heat damage during drying and chemical interaction of fat oxidation products with meal proteins. Protein bioavailability is reduced and dietary stress may be introduced into hatchery feeds. The basic hypothesis of this investigation is that ration protein quality can influence the survival of smolts and the ultimate return of adults. Improved hatchery production would be better able to reestablish natural runs of salmon in the Columbia River and its tributaries and maintain and improve the genetic integrity of specific stocks. The general approach being used to prove this hypothesis involves a comparison of the hatchery growth response, survival and return of coho and chinook salmon reared on nutrient dense rations containing a very high quality fish protein complement and commercial ration relying on commercial fish meals as a source of protein. Coded wire tagging experiments are being conducted on replicate brood years of test and control fish to determine the influence of ration protein on survival. The growth response of both coho and fall chinook salmon between mid February of 1985 to release in May was altered from that expected by poor test ration palatability. Palatability problems were traced to one of two lots of herring oil used to prepare rations. (ERA citation 11:041712)