process sharply reduced the content of some of the B-coraplex vit- 

 amins in the salmon viscera,, This reduction in the vitamin content 

 may have had a masking effect on the temperature evaluation. Regard 

 less of t K e cause, the ace-tone extracted meal did not prove superior 

 to the tunnel-dried meal and because of its reduced vitamin content 

 must be considered inferior. 



On the basis of these experiments, it is indicated that high 

 temperatures such as occur in flame drying may have a deleterious 

 effect on the growth potential oT fish meals. Although the dif- 

 ferences in growth rate did not prove statistically significant , the 

 trend indicated that high drying temperatures produced salmon offal 

 meals of an inferior growth potential. This inference is sub- 

 stantiated by the significantly greater gains made by fish fed 100- 

 degree, tunnel-dried, salmon viscera meal when compared with those 

 fed a similar diet containing an identical meal dried at ikS degrees. 

 The acetone extraction of salmon viscera at room temperatures did not 

 increase the growth response of fish fed this product over that of 

 those fed meals prepared by the tunnel-drying process. 



The effect of water temperature on the utilization of meal 

 supplements was demonstrated during the 19^8 feeding trials. Prior 

 to 19U8, the diets were tested for a 12 or lit- week period at an 

 average water temperature of approximately 5k degrees. In these 

 feeding trials the addition oT high protein meals resulted in an 

 impetus to the growth rate and a low mortality rate. In the 19h8 

 experiments these results were not duplicated for the entire ex- 

 perimental period. During the first 12-weeks of the feeding trials 

 the water temperature averaged kk-9 degrees , In this period the 

 growth response due to the addition of meals in the diets was not 

 measurable and the mortality rates were greatly accelerated when 

 compared to control diets from which meals were excluded. During 

 the second 12 weeks the water temperature averaged £U.3 degrees. 

 The rise in water temperature resulted in an increase in the gain* 

 in weight and a reduction in mortality in the fish fed meal diets, 

 more comparable to the results attained in the previous feeding 

 trials. 



The effect of water temperatures on the utilization of meals 

 is shown in Figure 2o To demonstrate the effect four diets were 

 selected. Diet 1 was the standard beef liver control. Diet 2 

 contained the standard meat and viscera mixture and 10 per cent 

 of llr5-degree salmon viscera meal. This diet was chosen for com- 

 parison because it contained an identical meal to that used in the 

 Cortland No. 6 meal mixture. Diet k consisted of the recommended 

 Cortland diet and included lj? per cent beef liver, 35 per cent hog 

 spleen and 50 per cent of the Cortland No. 6 meal mixture. Diet 8 

 was the standard meat and viscera mixture fed at the 100 per cent 

 level,. Diet 8 served as a control on Diet 2 and measured the 



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