4. PROJECTED GROW-OUT EXPERIMENTS (1976 – 1977)

Animals for this phase of the work will be taken from the wild fry collected in March/April 1976. Procedures will follow those developed during the 1974 – 75 studies, with emphasis on conversion rates and time required to reach marketable size of ca 250 – 300 g. Experimental design comprises eight dietary variations with four replicates of each, for a total of 32 tanks. Grow-out diets will be prepared in pelleted form.

Diets are designated as follows:

1. A-2. (based on 40 % protein, of which 15 % is fish meal, and a vitamin premix potency of 20 %). This will serve as the control diet to be compared with the previous grow-study and the nutritional value of the various substitutions, especially increased protein, increase in fish meal percentage, addition of fish oil and solubles and increased vitamin level. Formulations may change based on results of fry studies. If fish hydrolysate is growth promoting, this will be added to grow-out diets.

2. A-2 (A-1) - 40 % protein; vitamin premix potency at 100 %.

3. A-2-m-1 - 40 % protein with fish meal levels increased to ca 25 % (subsequent decrease in soya); vitamin potency at 100 %.

4. A-2-M-2 - 46 % protein with fish meal portion at 25 %, addition of yeast and feather meal (possibly use of a soya concentrate) and reduction of wheat to achieve 46 % protein level; vitamin potency at 100 %

5. A-2-M-3 - 40 % protein with fish meal under 30 %; addition of fish oil and solubles at 2 – 3 %, 5 % oil supplement total (fish oil 3 %, soya oil 2 %);vitamin potency at 100 %.

6. A-2-M-4 - 46 % fish oil and solubles added as in A-2-M-3; vitamin potency at 100 %.

7. A-2-M-5 - 40 % Protein; fish oil and solubles added as in A-2-M-3; vitamin potency at 20 %.

8. A-2-M-6 - 46 % protein; fish oil and solubles added as in A-2-M-3; vitamin potency at 20 %.

The aforementioned permit the following comparisons: