17 



in the various control mashes, and varying amounts of ground limestone, soybean 

 oilmeal, and wheat were replaced by these fish meals to balance the nutrients. 

 Growth rates of the chicks fed mashes containing the lower levels of starfish 

 meal were as good as, or better than, those obtained with the control mashes, but 

 the rates were lower for the groups fed the 8 and 12 percent levels of starfish 

 meal. The mean gain in liveweight of the group fed the 12 percent level of star- 

 fish meal was only 60 percent that of the control group. It was concluded that 

 the starfish meal could be used to supply all of the calcium and some of the animal 

 protein, it having the- same growth-stimulating qualities as sardine meal protein. 

 The calcium content limited the amount of starfish meal which could be used. 



Morse, et al, (1944) carried out their study with starfish meal with an ex- 

 perimental lot of about one ton of meal produced in commercial scale operations . 

 The starfish meal was included in diets at 4 and 8 percent levels and compared 

 with those containing a 4 percent level of crab meal and a 2.5 percent level of. 

 fish meal. The protein level and calcium: phosphorus ratio were approximately 

 balanced. There were no significant differences in mean gains of liveweight be- 

 tween any of the four groups of chicks after 8 weeks . Smaller groups were con- 

 tinued on experiment and fed the diets containing 2.5 percent fish meal and 8 per- 

 cent starfish meal until the 14th week. At this time, the two groups were still 

 about equal in size and feathering. At this level, the starfish meal plus dicalcium 

 phosphate adequately replaced both the fish meal and meat scrap. 



Although the tests varied somewhat in detail of experiment, all of these in- 

 vestigators have used newly-hatched chicks. Their conclusions agree in substance; 

 namely, that small amounts of starfish meal can replace other animal proteins as 

 a source of supplementary protein permitting approximately equal growth on an 

 equal-protein basis. When several levels were fed, poorer growth usually resulted 

 when more than 6 percent starfish meal was included in the diets . It was generally 

 concluded that this effect was due to the resultant high levels of calcium, to 

 the unbalanced calcium: phosphorus ratio, or to both factors. 



STARFISH MEAL FOR GROWTH OF RATS 



The work reported herein antedates the 6 papers just discussed, having been 

 carried out in the summer and fall of 1942. This fact is mentioned in explanation 

 of the inclusion in these tests of certain preliminary studies exploring the possible 

 effects of the high levels of calcium in starfish meals. 



The method of preparation of the meals used in these feeding tests has been 

 described in Part II of this series dealing with chemical composition. In brief, 

 starfish drained of free liquid which had separated in shipping were dried in ovens 

 heated by steam coils at about a temperature of 60° C. Most of the foreign matter 

 was removed before drying. In the first rat and chick tests, the extracted meal 

 referred to was that remaining after the starfish oil was extracted. A quantity 

 of this meal was available and it was fed in amounts equivalent to the protein 

 in the diet containing the highest level of starfish meal fed to find out whether 

 the oil had an adverse dietary effect which had to be considered in producing feed- 

 ing meals . 



As a preliminary to the feeding tests, the nutritive quality of the protein 

 was determined by a nitrogen metabolism study. Six adult male rats were fed a 

 protein-free diet during a preliminary and following period of 10 days, and the 

 starfish protein to be tested was then fed during a middle 4-day period according 

 to the method of Mitchell (1924). Feces and urine were collected for each period. 



