392 U. S. BUEEAU OF FISHERIES 



as good results as fish menl. but that with bhxxl aHniniin alone, although for 

 the first fortnight the .trains were as good as with fish meal, afterwards growth 

 slowed down and was no better than with a purelj' grain ration. 



They further stated that " both milk and eggs consist very kirgely 

 of protein and mineral matter. Three gallons of milk contain 

 about 1 pound of protein, three-fourths of an ounce of lime (CaO) 

 and an ounce of phosphorus (P2O5) so that a cow giving that amount 

 of milk per day loses these quantities of essential substances that 

 must be made good in the ration, unless it draws on its tissues and 

 bones for them. Egg, like fish meal itself, consists almost entirely 

 of protein, minerals, and fat. For milk cows and poultry, therefore, 

 fish meal seems a most suitable food and it is not difficidt to under- 

 stand why good results are obtained in feeding it to these animals." 

 Something to be remembered emphatically is a statement of the 

 authors as follows: ''With regard to meeting the requirements for 

 mineral matter fish meal is so rich in this that if sufficient be given 

 to yield the necessary amount of protein there is likely to be more 

 than sufficient mineral matter present." They said that " in fish 

 meal the ratio of calcium to phosphorus is about the same as is 

 required for growth, and it might be expected that the percentage 

 utilization would be high." This fact was subsequently proved by 

 the authors in feeding experiments. 



Edwards (1923) recommended fish meal along with corn to supply 

 sufficient minerals in hog rations. 



In feeding fish meal to dairy cows, Hansson (1926) said that the 

 large percentage of minerals present in fish meal was considerably 

 in its favor in addition to its high protein content. 



In studying rations for fattening pigs, Davidson (1928) stated 

 that fish meal w^as found to be valuable not only for its protein con- 

 tent but particularly for the amount and proportions of mineral 

 constituents. 



Robertson and Baskett (1929) reported that soybean meal was 

 not as good as fish meal in poultry rations, unless the soybean meal 

 was supplemented with minerals. 



According to Jenn}^ (1929), " Kelp, the aquatic crop, and the fish 

 living in the sea have in them the mineral matter necessary to 

 optimum nutrition — by feeding the milk cow certain proportions of 

 kelp and ground dried fish (tuna fish minus the wdiite meat) in her 

 rations, we can supply the natural amounts of the essential minerals 

 her feed lacks and at the same time provide animal proteins of the 

 best quality to the ration." The author also said that the feeding 

 of these marine products increased the iodine content of the milk 

 many times its original centent. 



Mann (1930) reported kelp, a dried seaweed, to be an excellent 

 source of organic mineral salts for animal feeding. Feeding tests 

 indicated that kelp was a better and cheaper source of minerals 

 than an inorganic mixture of minerals. He states: 



Feeding experiments indicate these are in the proper proportions to meet 

 the requirements of the animal body. No great quantities seem to be needed, 

 but a little seems to make a great deal of difference in the results from feeding. 

 The best gains (with cattle) were made on a daily apportionment of 2i/l> 

 ounces of the supplement (a commercial mixture of fish meal and kelp). 



Insufficient iodine cau.ses goiter, and this disease is largely corrected with 

 the use of kelp in the feed. Fed to pregnant animals it will prevent the 



