[Use of food treated with gamma radiation in the feeding of rainbow trout (Salmo gairdnerii irideus)].

A rainbow trout diet, partially prepared with agroindustrial by-products, including laying hen's dung, was treated with gamma radiation (25 KGy). The objective was to reduce the microbiological contamination and test its effect on weight gain, feed efficiency and mortality of trouts. For this purpose, two groups of trouts were compared: one received irradiated food, and the other the same diet, but without treatment. The experience was carried out through a period of 32 weeks, during the free growth stage (from 2 to 20g). Microbiological contamination decreased from high values (greater than 6 X 10(6) germs/g of food) to acceptable levels (less than or equal to 3 X 10 germs/g of food), but the parameters measured in trouts, did not show any difference among both groups.