Factor H in the Nutrition of Trout

Abstract

To determine the nutritional requirements of trout, 30 different groups of 50 fingerlings each were fed upon purified diets made up in the same manner as those commonly fed to rats. Trout are stunted in growth when they are maintained upon a ration that contains only 10 % casein; the normal growth rate is resumed if changed to a ration of raw meat. Upon protein levels higher than 10% the trout grow at sub-normal rates, but die much sooner than those stunted by low protein feeding. Trout fed upon dried skim milk display excellent growth for several mos., then suddenly die. The addition of known vitamin supplements can not be shown to have any influence upon either growth or mortality of trout. Raw meat is the most effective agent in promoting an optimum growth, while dried or cooked meats are failures. Raw meat contains large amounts of some factor essential for the growth of trout; dried milk contains a small amount. This factor is not identical with vitamins A, B, C, D, or E.