My buddies Alvin and Leong in Singapore have continually tried to ferret out new information sources on goldfish care. I really admire their efforts to consult with experienced hobbyists and find informative books. Occasionally they share some of this information with me.
I want to pass along a couple of things here. The first is a set of goldfish recipes used by Chinese zoos. Leong was kind enough to translate these from a Chinese goldfish text. The second is some information Leong found in a Japanese article on the digestibility of different foodstuffs for goldfish.
A strong word of caution: this information is provided for your interest. The recipes strike me as potentially very high in protein, but this may work very well for pond raised fish that have access to natural food as well as prepared food. The digestibility information is interesting, but I would not assert that all the experimentally examined foods are suitable staples for goldfish. So use common sense for any use you might consider making of this information.
a. Fish Powder - 40% b. Bran - 60% c. Every kg add 1.2 gm yeast & 10 gm gelatin.
a. Fish Powder - 30% b. Bran - 70% c. Every kg add 1.2gm yeast, 10 gm gelatin & 25 Vitamin.
a. Fish Powder - 150gm b. Bran - 200gm c. Yeast - 45 gm d. Some Fiber - 50gm (used like gelatin) e. Water - 500 to 600ml f. Vitamin - some.
a. Beef or pork heart - 500gm b. Small dry fish or "animal type" protein - 1500gm c. Dry shrimp - 250gm d. Small amount of wheat bran.
Leong says the bran in the above recipes is wheat bran. I assume the fiber is also a bran ... perhaps the wheat bran is actually wheat germ; need to check on the translation.
The following is from an unidentified Japanese article.
Food (%) % digestibility ----------- ---------------------- 1. Meat 50%, Starch 50% 93% 2. Cheese 50%, Starch 50% 96% 3. Horse meat 80%, Starch 10%, Oil(?) 10% 97% 4. Dry Silkworm 100% 79% 5. Skim Silkworm 100% 87% 6. Fish meat 100% 92% 7. Seaworm (?) 100% 71% 8. Spirulina 80% Starch 20% 57% 9. Spirulina 20%, Starch 80% 26%
I have no idea of the experimental method used here. One thing that is very interesting to me is the digestibility of the mixes with Spirulina algae; not very high! I have seen authors question the digestibility of Spirulina elsewhere in human nutrition books. It seems to be a worthwhile ration additive, but not a suitable principle feed component.