Table 3. — Effect of meat on protein deposition and 

 utilization and on mortalities 



Table Ii. — Effect of vitamin supplementation on protein 

 deposition and utilization and on mortalities 



fish receiving diets witJn 30 percent protein 

 would consume only a part of the food present 

 at each feeding. In order to prevent this loss, 

 the protein level of these diets was lowered to 

 27.5 percent. No further trouble was encoun- 

 tered with the fish refusing food. 



12 weeks. — The 25 -percent protein diets 

 produced significantly more weight and greater 

 protein deposition than comparable diets fed at 

 the 20 -percent level of protein intake . There 

 was no difference in protein utilization. The 

 2 7. 5 -percent protein diets, when compared with 

 diets of 25 percent protein with comparable 

 caloric intake and meat supplementation, pro- 

 duced fish which had significantly better protein 

 deposition and equal protein utilization . 



24 weeks. --Results at the end of the exper- 

 iment were similar to those at 12 weeks. The 



25 -percent protein diets produced fish with 

 significantly greater protein deposition than did 

 comparable diets at the 20-percent protein level. 

 Protein utilization factors did not differ signifi- 

 cantly between comparable diets . In turn the 

 2 7. 5 -percent protein diets produced significantly 

 greater protein deposition than did comparable 

 diets at levels of 25 percent protein. There was 

 no difference in protein utilization. Table 5 

 summarizes the results of comparable diets at 

 the 25- and 2 7. 5 -percent protein levels at the 

 end of 24 weeks. 



These results would indicate that under these 

 experimental conditions and at a constant water 

 temperature, diets that provided a protein intake 

 of 27.5 percent were superior to the comparable 

 diets that supplied 20 and 25 percent protein. 

 However, there is a trend, though not statisti- 

 cally significant, for the protein utilization 

 factors at the 27. 5 -percent protein level 



