Partial and total replacement of soybean meal protein by canola or cottonseed meal protein in diets of <em>Leporinus macrocephalus</em> (Garavello & Britski, 1988) fingerlings

Abstract

The effects of soybean meal (SB) protein replacement by canola meal (CN) or cottonseed meal (CT) protein in diets of Leporinus macrocephalus (Characiformes, Anostomidae) fingerlings are provided. Assay was carried out during 60 days. Three hundred fingerlings with mean initial weight of 1.00g were distributed in a block randomized design with six treatments and five replicates. Isoprotein diets contained SB, CN, CT, SB+CN, SB+CT and CN+CT as protein source. Fingerlings fed on diets with SB, SB+CN, SB+CT showed better final mean weight and protein efficiency rate values (p < 0.01) than the ones fed on diets with CN. The feed/gain of the fingerlings fed on diets containing FS, FS+FC e FS+FA had better values than the ones fed on CN diets. However, they did not differ from the other diets. Survival rate was not affected (p > 0.05) by different diets linear reduction (p < 0.05) of final weight and protein efficiency rate and increase of feed/gain of SB protein replacement levels by CN protein in diets were reported. Quadratic effect (p < 0.05) of SB protein replacement by CT protein in diets with final weight, feed/gain and efficiency protein rate with best values at 28.90, 24.51 and 25.74% of protein replacement levels, which correspond to 40.42, 34.23 and 36.00% of CT inclusion in diets, respectively, was also recorded. CN and CT may be included in the diets of L. macrocephalus fingerlings, replacing 50.00% of SB protein.