exceeded the control diets. Diets 2 and 8, by about $0 percent if the da.fference 

 between weight gains of comparable diets during the warm-water period is used 

 as the basis of calculation. 



From the lack of differences between the meat-viscera mixture and the 

 diet wit>iout hog spleen it was concluded that an increase in the vitamin content 

 and a slight increase in the orotein content made no measurable contribution 

 over and above the neat-viscera combination when fed to blueback salmon. 



Crab Meal Supplement 



Crab meal was used to supplement the meat-viscera mixture to determine 

 the effect of crab meal on growth and sunrival when added at the S percent level. 

 The crab meal was derived from the total crab scrap of the blue crab ( Callin - 

 ectes sapidus) and reduced to a dry powder in a conventional, rotary, flame-drier. 



Diets U and 5, used in this test during the cold-water period, consisted 

 of 21 percent each of beef liver, hog liver, and hog spleen, 32 percent of salmon 

 viscera and 5 percent of crab meal. During the warm-water period, ^iet U remain- 

 ed the same and Diet 5 was changed to 19 percent each of beef liver, hog liver, 

 and hogi splfeen, 28.5 percent Salmon viscera, 'li, 5 perfe^nt '"of crab meal, and 10 

 percent of vacuum-dried Salmon viscera meal. 



Results at the end of the first 12 weeks (the cold-water period) 

 showed that crab meal caused no differences in groirt.h, but at the end of the 

 warm-water period, the diet supplemented with crab meal (Table 1, Diet U)> pro- 

 duced a significantly higher final raeaxi lot weight than did Diet 2, a comparable 

 diet which had no crab meal. There were no significant differences in mortalities. 

 The addition of vacuiora-dried salmon viscera meal to Diet 5 during the 12 weeks of 

 warm water provided a 26 percent gain in weight which was the smallest percent 

 gain yielded by vacuum-dried salmon viscera meal in this expdriment. 



The slightly increased growth brought about by crab meal alone in the 

 meat-viscera mixture during the warm-water period shewed that crab meal exerted 

 its greatest effect on growth during the warm-water period. The small increase 

 has no special significance in blueback salmon culture, however, since an equal 

 amount of salmon viscera meal during the warm-water period assuredly would have 

 made a greater contribution. Of some importance was the fact that crab meal 

 could be used during the cold-water period at the 5 percent level vrithout a res- 

 ulant mortality or diminution in mean low weight. 



Substitution of Salmon Eggs for Salmon Viscera 



In the I9U9 feeding trials (Robinson et al. ]93'1) salmon eggs in single 

 component rations produced more growth during the warm-water period than did 

 whole salmon viscera, and that during the cold-water period the differences were 

 difficxilt to judge by mean lot weights because of the very serious mortalities 

 (up to 50 percent) caused by both the salmon viscera and salmon egg diets. The 

 diet used in the previous experiment, 90 percent salmon e^i^js or salmon viscera 



