Abstract

MARTINS SOARES, Claudemir; HAYASHI1, Carmino; WILSON, Rogério Boscolo  and  MEURER, Fábio. DIFFERENT MILLING DEGREE OF INGREDIENTS IN PELLET DIETS FOR NILE TILAPIA (OREOCHROMIS NILOTICUS L.) DURING THE GROWTH PHASE. PERFORMAN CE AND APPARENT DIGESTIBILITY . Zootecnia Trop. [online]. 2003, vol.21, n.3, pp.275-288. ISSN 0798-7269.

To evaluate the effect of diets with different milling degree of ingredients (MDI) in pellet diets on performance and carcass characteristics of tilápia do Nile, 100 fingerlings were used with initial average weight of 11.92 ± 0.29 g, which were distributed in a randomized block design, with four treatments and five replications. The experimental diets had different MDI, as 0.50, 0.75, 1.00, and 1.50 mm mesh. It was observed a quadratic effect (P<0,05) on final mean weight, percent weight gain, total length, apparent feed conversion, and protein efficiency rate with the best values of 0.782, 0.789, 0.739, 0.656, and 0.734 mm. The body and fillet yields and visceral fat had the smaller values 0.969, 0.100, and 0.877 mm, respectively. The carcass yield showed a linear increase and the condition factor was not affected by the MDI. It was observed a quadratic effect (P<0,02) of the ingredients milling degree on dry matter, crude protein, and gross energy digestible apparent with maximum values of 0.691, 0.572, and 0.716 mm, respectively. It may be concluded that the milling degree of ingredients at 0.79 mm was the more adequate in pellet diets for Nile tilapia during the growth phase.

Keywords : Milling degree; Nile tilapia,; Oreochromis niloticus; particle size; performance.