Avaliou-se a inclusão dos farelos da vagem da algaroba (Prosopis juliflora) e folha da mandioca (Manihot esculenta) em rações para tilápia do Nilo (85,22 ± 3,13 g). Foram utilizados 336 peixes, distribuídos em 28 tanques (120 L), em esquema fatorial 2 x 4, duas fontes de óleo e quatro níveis de farelo (0, 5, 10 e 20%) (n = 4). Ao final de 60 dias, foram avaliados o desempenho zootécnico (consumo de ração, ganho de peso, conversão alimentar aparente e taxa de sobrevivência) e a composição da carcaça dos peixes. Para análise da histologia intestinal, foram mensuradas a altura e a densidade das vilosidades. O desempenho zootécnico, a composição da carcaça e a densidade das vilosidades intestinais não foram afetados (p > 0,05) pela fonte e nível de inclusão de farelo. Houve efeito significativo do nível de inclusão dos farelos sobre a altura das vilosidades intestinais, com comportamento linear decrescente, indicando que quanto maior o nível de inclusão de farelo, menor a altura das vilosidades. Os farelos estudados podem ser incluídos em até 20% em rações de tilápias do Nilo sem comprometer o desempenho zootécnico e alterar a composição corporal, no entanto, a presença destes coprodutos em rações pode resultar em efeito deletério sobre as vilosidades intestinais dos peixes.

This work evaluated the inclusion of mesquite bean bran (Prosopis juliflora) and cassava leaf bran (Manihot esculenta) in diets for Nile tilapia (85.22 ± 3.13 g). Three hundred and thirty-six fish were distributed in 28 fiberglass tanks (120 L) in a 2 × 4 factorial scheme for two sources of oil and four levels of bran (0, 5, 10 and 20%) (n = 4). After 60 days, growth performance (feed intake, weight gain, apparent feed conversion and survival rate) and fish body composition were evaluated. Heights and density of villi were measured for morphometric analysis of the intestinal mucosa. Animal performance, body composition and villi density were not affected (p > 0.05) by the source and level of inclusion of bran. There was a significant effect of the level of inclusion of bran on villi height, with a linear trend, indicating that the higher the inclusion levels of bran, the lower the height of the villi. The bran studied can be used in diets for Nile tilapia up to 20% without compromising growth performance and body composition change, but the presence of these by-products can result in a deleterious effect on fish villi.

This study was conducted to evaluate performance and body composition of tilapia (Oreochromis niloticus) fed diets containing byproducts aerial parts of cassava meal (Manihot esculenta), mesquite pod meal (Prosopis juliflora), cocoa meal (Theobroma cacao) and palm kernel cake (Elaeis guineensis) and to analyze the economic viability of the feed. A total of 1,350 juvenile males (100 g) were distributed in 15 cages (1 m³) in completely randomized design with five treatments (basal diet and four test diets) and three replicates. The following aspects were evaluated: final weight, total feed intake, total weight gain, feed conversion, specific growth rate, protein efficiency ratio and survival rate, dry matter, crude protein, fat and ash body, the average cost of feed per kilogram of weight gain and economic efficiency rate. No differences were observed for total consumption of food or survival rate. For other variables, the inclusion of cocoa and cassava meal impaired fish performance. No differences were observed for dry matter, crude protein and body ash. The lower body fat accumulation was recorded for the tilapia fed palm kernel cake. The best economic indicators were found to diets containing palm kernel cake. The byproducts evaluated can be used up to 150 g/kg in feed formulation, providing good performance and economic rate for Nile tilapia.

The objective of the present study was to evaluate the apparent digestibility coefficients of dry matter (DM), crude protein (CP) and gross energy (GE) of the following agro-industrial byproducts: cassava leaf (Manihot esculenta), mesquite bean (Prosopis juliflora), cotton (Gossypium species), cocoa (Theobroma cacao), soursop (Annona squamata) and African oil palm cake (Elaeis guineensis) for Nile tilapia (Oreochromis niloticus). Fish from two weight classes (200±11 and 300±32 g) were stocked in tanks and fed a reference diet plus 30% of one tested byproduct with the addition of 0.1% chromic oxide. The fish were routinely moved to digestibility aquariums for feces collection, in a completely randomized design (n=3). The apparent digestibility coefficient (ADC) values between the two weight classes were similar, but differed between the byproducts for DM, CP and GE. The highest ADC DM, ADC CP and ADC GE for 200-g and 300-g tilapias were, respectively, 0.58 and 0.53; 0.77 and 0.78; 0.66 and 0.62 for the soursop bran and 0.52 and 0.51; 0.77 and 0.80; 0.66 and 0.60 for the palm cake, respectively. The cotton and cocoa bran had the worst results of ADC of DM in two weight ranges (means of 0.34 and 0.37 g/100 g, respectively) while the mesquite bean had the lowest ADC of CP and GE, with means of 0.28 and 0.14 g/100 g for 200-g and 300-g tilapias, respectively. The byproducts analyzed may be used in formulating diets for Nile tilapia adults, observing their contributions to the digestibility of nutrients and energy for the species.