Different milling degrees of ingredients in diet for Nile tilapia (Oreochromis niloticus L.) during growth phase

Abstract

The trial aimed to compare pelletized diets with different milling degrees (0.50 or 1.50mm) on the performance and food transit velocity rate (FTVR) of Nile tilapia during growth phase. Forty animals with mean initial weight of 68.95 ± 13.30 g and total length of 15.94 ± 1.06 cm, were distributed in a completely randomized design with two treatments and five replications in 500l concrete tanks. Significant differences (P < 0.05) were observed according to the mean values of final weight, final length, daily weight gain, feed intake and feed conversion, and the worst results were with diet of 1,50mm. There was no difference when using diets of 0.50 or 1.50mm on condition factor, carcass and fillet yields, and on visceral fat percentage of the fishes. The FTVR was faster for the 1.50mm treatment. It was concluded that the use of 0.50mm milling degree diet promoted the slowest food transit velocity and the best performance for Nile tilapia during growth phase.