Antioxidants have been used in commercial fish foods in the USA for over 20 years. Although hundreds of chemicals have been tested, only a few have shown the qualifications necessary to make them suitable for use in preventing undesirable oxidations in feedstuffs, in finished feeds, and in the guts and carcasses of animals. In order for an antioxidant to be useful in animal feeding, it must have the following qualifications:
(a) it must be effective in preserving animal and vegetable fats, vitamins, and other feed qualities subject to oxidative destruction;
(b) it must be non-toxic to man and to farm animals (i.e., chickens, swine, fish, etc.);
(c) it should be effective at very low concentrations; and
(d) it must be low enough in cost to be economically practical.