A BIOLOGICAL ASSAY OF THE NUTRITIONAL VALUE 

 OF CERTAIN SALMON CANNERY WASTE PRODUCTS 



By Roger E. Burrows and Neva L. Karrick5y 



Introduction 



There is a critical need for a large source of an inexpensive and 

 nutritionally adequate supply of food for feeding fish. In the past 

 fev years the demand for hatchery-bred fish has increased tremendously. 

 At the same time the cost of fresh meat and meat waste which has been 

 a large part of diets in the past has increased and the supply of these 

 foods has decreased. Ae a result, the amount of fish used in the diet of 

 hatcheries has increased during this period. In the hatcheries in Wash- 

 ington State alone, the consumption of fish products has increased from 

 270,590 pounds in 1934 to approximately 4,000,000 pounds in 1946, and 

 directors of hatcheries have stated that they could use a much larger 

 amount if the waste could be properly processed. This means that a method 

 of processing and preserving must be developed that is economical and 

 retains in the finished product the essential nutritive factoj*s known 

 to be present in the raw fish waste. 



The necessity for an adequate supply of food for fish will become 

 even greater as the number of dams along the Columbia River increases 

 and the demand for hatchery-bred fish becomes greater. Another possible 

 market demand is due to the current trend in private and state sports 

 fish hatcheries toward a longtr holding period. Some hatcheries do not 

 release fish until they are full size, with the obvious result that more 

 food is needed than previously. 



Not only must a cheap and plentiful source of food be found, but 

 also a diet must be worked out that will supply the factors necessary for 

 optimum fish growth and for the production of healthy fish. These factors 

 are still an unknown quantity to those working on fish nutrition. A re- 

 view of the work which has been done to determine the composition of an 

 adequate diet for fish has been prepared by the U. S. Fish and Wildlife 

 Service and will be published as a Fishery Leaflet. This leaflet includes 

 a discussion of the mechanics of feeding, present knowledge of the necessary 

 nutritional elements of foods which have been tested for their content 

 of the anti-anemia factors, and of methiods of preservation which have been 

 tried. The abstracts of the references in the bibliography of "The Nu- 

 trition of Fish" are available on microfilm for purchase from the Office 

 of Technical Services, Department of Conmerce, Washington 25, ^. '^. 



^7 Aquatic Biologist, Leavenworth Laboratory, Division of Fishery Biology, 

 U. S. Fish and Wildlife Service, and Chemist, Alaska Fisheries Experimental 

 Commission, Seattle Fishery Technological Laboratory. Acknowledgement is 

 made to ^^r. Leslie A. Robinson for technical assistance in performance of 

 the hatchery feeding tests. 



^9 



