ABSTRACT A 90-day feeding trial was conducted to estimate the dietary lysine requirement of adult lambari ( Astyanax altiparanae ), based on growth performance, whole-body composition, muscle development, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. Six isoproteic (345.0 g kg−1) and isoenergetic (19.51 MJ kg−1) diets were formulated, and crystalline L-lysine was added to obtain diets with lysine concentrations of 12.13, 13.31, 15.36, 18.79, 19.92, and 23.02 g kg−1 dry diet. Female adult lambari (n = 480; weight of 4.96±0.02 g) were distributed into 24 (70 L) aquaria and fed the experimental diets six times daily. Fish fed 12.13 to 19.92 g kg−1 lysine showed increased weight gain and percent weight gain, and fish from those treatments also showed improvement in final carcass quality by a decrease in whole-body lipid content. Fish fed 12.13 g kg−1 lysine showed lower ALT and AST activities in blood serum when compared with fish fed the highest lysine levels. No differences were observed in muscle growth in fish fed graded lysine levels. According to the broken-line model analysis of weight gain and dietary lysine levels, the dietary lysine requirement of adult lambari is estimated at 18.72 g kg−1 (5.41% of dietary protein).

RESUMO A digestibilidade do trigo e seus co-produtos foi avaliada em dietas extrusadas para juvenis de tilápia do Nilo. Foram avaliados os coeficientes de digestibilidade aparente (CDAs) de matéria seca (CDAMS), energia bruta (CDAEB), proteína bruta (CDAPB), aminoácidos essenciais (AAEs) e aminoácidos não essenciais (AANEs) do triguilho, trigo, farelo de trigo, fibra grossa de trigo e gérmen de trigo. Utilizou-se uma dieta de referência e dietas de teste, com 5,0g/kg de óxido crômico (Cr2O3) como indicador externo. O CDAMS, CDAPB e CDAEB foram maiores (P< 0,05) no triguilho, trigo e germen de trigo do que para farelo de trigo e fibra grossa de trigo. Os CDAs de todos os aminoácidos (AAs) foram maiores que 80%, exceto para treonina no farelo de trigo e fibra grossa de trigo, superior a 90% para triguilho e germen de trigo. Os valores de todos os ingredientes investigados foram elevados para CDAPB, e os CDAs de AAEs e AANEs. Uma forte correlação negativa foi detectada para fibra bruta e cinzas com os ADCs de matéria seca, energia bruta e proteína bruta. De maneira geral, os ingredientes provenientes do trigo possuem boa digestibilidade da proteína e aminoácidos, porém o alto conteúdo fibroso reduz os CDAMS e CDAEB, em dietas extrusadas para a tilápia do Nilo.

SUMMARY In the present study, we investigated the digestibility of wheat and its coproducts in extruded diets for juvenile Nile tilapia. Specifically, we evaluated the apparent digestibility coefficients (ADCs) of dry matter (ADCDM), gross energy (ADCGE), crude protein (ADCCP), essential amino acids (EAAs), and non-essential amino acids (NEAAs) in winter wheat, spring wheat, wheat middling, wheat bran, and wheat germ in a diet fed Nile tilapia. A reference diet and test diets were used, with 5.0g/kg chromic oxide (Cr2O3) as the external indicator. The ADCDM, ADCCP, and ADCGE were higher (P< 0.05) in winter wheat, spring wheat, and wheat germ than for wheat middling and wheat bran. The ADCs of all amino acids (AAs) were >80%, except for threonine in wheat middling and wheat bran, exceeding 90% for winter wheat and wheat germ. The values of all investigated ingredients were high for ADCCP, and the ADCs of EAAs and NEAAs. A strong negative correlation was detected for crude fiber and ash with the ADCs of dry matter, gross energy, and crude protein. In general, wheat ingredients have good digestibility of protein and amino acids, but high fiber content reduces CDAMS and CDAEB in extruded diets for Nile tilapia.

Resumo O objetivo deste trabalho foi desenvolver massas de pizza com diferentes níveis de inclusão de farinha de atum (Tunnus spp.). Para a produção da farinha de atum, foram utilizados troncos de atum sem nadadeiras, cozidos por uma hora, prensados, moídos e desidratados por 24 horas a 60 °C. Foram elaboradas massas de pizza sem inclusão (0%) ou com inclusão de 5, 10, 15 e 20% de farinha de atum, sendo estas inclusões calculadas com base na quantidade de farinha de trigo. A farinha de atum e as diferentes massas foram analisadas quanto aos teores de umidade, proteína bruta, lipídeos totais, cinzas e carboidratos, além do valor calórico e do perfil de ácidos graxos. Análises microbiológica e sensorial foram realizadas nas massas de pizza. A crescente inclusão de farinha de atum resultou em aumento do teor de proteína bruta (10,89 a 18,94%), de lipídeos totais (4,63 a 5,89%) e de cinzas (2,54 a 3,54%) nas massas, sem influenciar no teor de umidade e no valor calórico. A inclusão de farinha de atum aumentou linearmente a quantidade de ácidos graxos da série n-3 nas massas, com aumento de 1,56 para 5,93 g/kg, em 20% de inclusão de farinha de atum. A relação entre ácidos graxos poli-insaturados e saturados da farinha de atum e das massas variou entre 1,21 e 1,85. A análise microbiológica demonstrou que as massas foram produzidas em condições adequadas de higiene. Observou-se que a inclusão de 5 a 20% de farinha de atum na massa de pizza não interferiu significativamente (p>0,05) nos parâmetros de aroma, sabor, impressão global e intenção de compra. Concluiu-se que a inclusão de 5 até 20% de farinha de atum é eficaz para melhorar o valor nutritivo e o perfil de ácidos graxos de massa de pizza.

Abstract The aim of this study was to develop pizza dough with different levels of tuna meal (Tunnus spp.). In order to produce tuna meal, tuna torsos without fins were used, cooked for 1 hour, pressed, milled and dehydrated for 24 hours at 60 °C. Pizza dough was produced without (0%) or with the addition of 5, 10, 15 and 20% of tuna meal, calculated based on the quantity of wheat flour. The tuna meal and different pizza pastries were analyzed for moisture content, crude protein, total lipids, ash, carbohydrates, caloric value and fatty acid profiles. Microbiological and sensory analyses were also carried out on the pizza pastries. The increasing addition of tuna meal resulted in gains in the crude protein (10.89 to 18.94%), total lipid (4.63 to 5.89%) and ash (2.54 to 3.54%) contents of the pizza pastries, not influencing the moisture content or caloric value. The inclusion of tuna meal linearly increased the quantity of n-3 series fatty acids in the pizza pastry, from 1.56 to 5.93 g/kg with the addition of 20% tuna meal. The ratio between the polyunsaturated and saturated fatty acids in the tuna meal and pizza pastries varied from 1.21 to 1.85. The microbiological analyses showed that the pizza pastries were produced under proper hygiene conditions. It was also observed that the addition of 5 to 20% of tuna meal to the pizza pastry did not significantly (p>0.05) alter the parameters of aroma, flavor, overall impression and purchase intention. It was therefore concluded that the addition of 5 to 20% tuna meal is effective in improving the nutritional value and fatty acid profile of pizza pastry.

Abstract Tilapia, salmon, tuna and sardine meals were prepared to develop and analyze extruded snacks with residue meal from fish processing. Residue meals were included in five types of corn snacks: control (0% fish meal) and four with 9% tilapia, salmon, tuna and sardine meals. Although moisture, lipids and carbohydrates rates did not differ among the snacks, protein rates increased with the increment of fish meal, reaching 11.85% in the tuna snack. Tuna and sardine snacks had the highest iron levels. The most abundant fatty acids were linoleic, oleic, palmitic, linolenic and stearic acids, with sardine, salmon and tuna snacks presenting the highest values of n-3 series fatty acids. Greater luminosity rate was reported for salmon snack, followed by tilapia, tuna and sardine snacks. The highest sensory acceptance index was verified in tilapia (78.07%) and salmon (72.40%). A 9% addition of residue meals of tilapia, salmon and tuna improved the nutritional value of the snacks.

This trial was conducted to determine the dietary digestible methionine + cystine requirement of Nile tilapia (550 to 700 g) based on the ideal protein concept. Six hundred fish were distributed in a completely randomized design with five treatments and four replicates, with 30 fish per experimental unit. The fish were fed diets containing approximately 262 g of digestible protein/kg, 3,040 kcal of digestible energy/kg and 7.90, 9.40, 10.90, 12.40 or 13.90 g of methionine + cystine/kg. The fish were hand-fed three times a day until apparent satiation for 30 days. No effects of dietary methionine + cystine on feed conversion ratio, daily protein deposition, whole body moisture, fillet moisture, crude protein, ether extract and ash, plasmatic HDL and LDL cholesterol were observed. Dietary methionine resulted in a linear increase in whole body protein and linear reduction in lipid deposition rate, hepatosomatic index, whole body ether extract and ash, plasmatic total cholesterol, plasmatic total lipids and plasmatic triglycerides. According to the Linear Response Plateau, the daily weight gain and fillet yield increased up to a level of 9.00 and 9.90 g methionine + cystine/kg of diet, respectively. The digestible methionine + cystine requirement of Nile tilapia is 9.00 g/kg for weight gain and 9.90 g/kg for fillet yield, corresponding to methionine + cystine:lysine ratios of 0.60 and 0.66, respectively.