FISHERY INDUSTRIES OP THE UNITED STATES, 1935 95 



in 1934, an investigation of tlie value of menhaden fish meal in the 

 feeding of calves and yearling heifers. Menhaden fish meals, pre- 

 pared according to diflerent methods of manufacture, have been 

 obtained for this test from, various factories. Results thus far have 

 indicated that both flame-dried and steam-dried menhaden meals are 

 valuable ingredients in the dairy ration. A full report on this work 

 will be published by the Maryland State Agricultural Experiment 

 Station and this Bureau in the Journal of Dairy Science. 



STUDIES OF THE CHEMISTRY AND NUTRITIVE VALUE OF FISH PROTEINS 



As discussed in a previous section of this report, our College Park 

 laboratory, late in 1935, began a study of the constituents of fish pro- 

 teins. This project not only includes a determination of the nutri- 

 tionally important amino acids in the proteins of various species of 

 fish and shellfish, but also digestibility and metabolism studies have 

 been begun in our nutrition laboratory to determine the biological 

 value of these proteins. As indicated previously, this work has not 

 progressed to a point where any results can be reported. 



NUTRITIVE VALUE OF MACKEREL 



A preliminary study of the nutritive value of the edible portion of 

 mackerel was made during 1935 by William H. Conway, Jr., in the 

 food products laboratory of the Massachusetts State College, Amherst, 

 Mass., in cooperation with our technological staff. This work was 

 supervised jointly by Dr. C. R. Fellers, of Massachusetts State 

 College, and Dr. F. P. Griffiths, of the technological stafl'. Mr. 

 Conway, a student assistant, was assigned to this study by the 

 National Youth Administration through the courtesy of the Massa- 

 chusetts State College. The results of this investigation are reported 

 in a thesis entitled "Studies on the Nutritive Value of Mackerel", 

 by William H. Conway, Jr., and submitted to the college. It was 

 found that mackerel is a good source of protein and that mackerel 

 flesh is a fair source of vitamins A and D, although not quite as good 

 a source of these vitamins as some other fish. 



MINERAL CONSTITUENTS IN FISHERY PRODUCTS AND BYPRODUCTS 



During 1935, E. J. Coulson, of our technological staff, stationed in 

 the laboratories of the State Medical College, Charleston, S. C, con- 

 tinued his study of the mineral constituents in various fishery products 

 and byproducts. This work not only included chemical determina- 

 tions of the amount of these various mineral constituents in the 

 difterent products studied, but also included tests of the nutritive value 

 of these minerals with experimental animals. Determinations of the 

 iodine content of most of the important products were completed 

 and the results were published in Fisheries' Investigational Report 

 No. 25, entitled "The Iodine Content of Some American Fishery 

 Products." This report contains determinations of the iodine con- 

 tent of about 25 kinds of fishery products. 



Studies of the iodine of haddock flesh and oysters, as compared with 

 the iodine of milk and iodine in the inorganic form of potassium iodide 



