is subject to greater oxidation than the unbound product. Although 

 packaged in waxed cardboard cartons, the effect of oxidation was ap- 

 parent on all outer surfaces of the diet indicating that some air did 

 penetrate the carton. The use of antioxidants to prevent oxidation 

 within the mass of the ground product and the employment of other, 

 more impervious, types of freezing containers offer possible solutions 

 to the problem of vitamin destruction in prepared diets during storage, 



SUMMARY 



The feeding trials conducted by the Leavenworth Laboratory 

 during the years 19UU, 19U5, 19^7, and 19U8 have evaluated the 

 effects of feeding certain meat products, fish products, dry 

 meal supplements, potential production diets, and prepared diets 

 held in frozen storage, as rations for blueback salmon. The 

 results of these evaluations may be summarized as follows: 



Meat Products 



1. Of the meat products tested flukey beef liver and flukey 

 hog liver were found to produce- a comparable growth response in the 

 fish. A combination of equal parts of beef liver and hog liver de- 

 monstrated a higher growth potential than either product fed se- 

 parately. Hog spleen, when combined with equal parts of either beef 

 or hog liver, made no measurable contribution to the growth rate 



in excess of either of these products alone. The anti-anemic 

 factor was present in the greatest amount in beef liver and to a 

 lesser degree in hog liver. Both these products contained more of 

 the anti-anemic factor than did hog spleen. 



2. Beef liver, ground and canned under 2f> pounds of vacuum, 

 showed evidence of a severe thiamin depletion, sufficient to cause 

 symptoms of a thiamin deficiency in the fish. 



Fish Products 



3. Salmon viscera produced an excellent growth response, superior 

 to any meat product tested, but was a less potent source of the anti- 

 anemic factor than was beef liver. Salmon viscera contained other 

 vitamins, particularly pantothenic acid, in minimal amounts which 

 caused vitamin deficiencies in the fish when the food intake was low. 

 Salmon viscera should be fed in conjunction with other products 



which will supply adequate vitamin fortification, especially during 

 periods of low water temperature. 



3U 



