Effects of Dietary Zeolites (Bentonite and Mordenite) on the Performance Juvenile Rainbow trout Onchorhynchus myskis

Abstract

Zeolites are natural or synthetic crystalline aluminosilicates with ion exchanging properties. Zeolites have been increasingly used i n v arious ap plication ar eas such as industry, agriculture, environmental protection, and eve n medi cine. Supplied as d ietary additives to l ivestocks such as swine, ru minants a nd poultry, they im prove weight gain, increase feed conversion ratios a nd promote animal health. The aim wa s to a sses the effects of the natural zeolites, bentonite and mor denite on the performance and body c omposition of ra inbow trout. During the feeding trial, quadruplicate groups of 15 rainbow trout (average initial weight ± SD , 1 04.2 ± 0.7) w ere g rown in f reshwater (salinity: 0; t emperature: 1 4-16 C) o ver 9 0 days. Fish were hand-fed, t wo times a day w ith diets o containing 40% crude protein supplemented with 0 ( control), 2.5, 5.0 a nd 10% bentonite or mordenite. Alpha cellulose replaced bentonite or mordenite in the control diet in order to k eep t he diet isonitrogenous a nd isoenergetic. There was a statistically significant d ifferences (P <0.05) in percent weight gain, specific gro wth rate and feed efficiency for f ish fed dietary bentonite at 5 and 10% and di etary mordenite at 2.5% compared to t hose fish on the control diet. Whole body composition of rainbow t rout was not adversely affected by the ad dition of bentonite o r mo rdenite to diets.