Valores de proteína, energia e aminoácidos digestíveis da farinha de carne e ossos para a tilápia do Nilo

This work was carried out to determine values of energy, protein and digestible amino acids from meat and bones meals with different crude protein levels. An in vivo digestibility trial was conducted with 180 juveniles of Nile tilapia (32.65 ± 4.52 g) GIFT strain, divided into conical tanks. Five meat and bones meals with 30.90, 35.26, 38.06, 41.38 and 44.36% crude protein were evaluated. To determine the apparent digestibility coefficients (ADC) was elaborated a reference diet based on soybean meal and poultry meal byproduct with approximately 3,120 kcal DE/kg and 32% of crude protein. The diets were composed of 70% of reference diet and 30% of each meat and bones evaluated. A completely randomized design with five treatments and three replications was used. The values of digestibility of gross energy, crude protein and amino acids and energy values, protein and digestible amino acids were subjected to linear or quadratic regression. It was observed a linear increase on the crude protein and digestible energy with , the increased levels of crude protein of meal. The average apparent digestibility of essential amino acids (including cystine and tyrosine) of meat and bones meals with 30.90, 35.26, 38.06, 41.38 and 44.36% crude protein were 82.21, 86.50, 90.06, 89.94 and 92.61% respectively. A great variation between the ADC of crude protein, gross energy and amino acids between and among each meat and bone meals was observed. Based on the ideal protein concept, the most limiting amino acids in meat and bone meal are, respectively: sulfur amino acids, threonine and isoleucine.Este trabalho foi realizado com o objetivo de determinar valores de energia, proteína e aminoácidos digestíveis da farinha de carne e ossos com diferentes teores de proteína bruta. Um ensaio de digestibilidade in vivo foi realizado com 180 juvenis de tilápia do Nilo (32,65± 4,52 g) da linhagem GIFT, distribuídos em aquários cônicos. Cinco farinhas de carne e ossos com 30,90; 35,26; 38,06; 41,38 e 44,36% de proteína bruta foram avaliadas. Para a determinação dos coeficientes de digestibilidade aparente (CDA) foi utilizada ração-referência com base em proteína de farelo de soja e farinha de vísceras de aves com aproximadamente 3.120 kcal de ED/kg e 32% de proteína bruta. As rações-teste foram compostas por 70% da dieta-referência e 30% de cada farinha de carne e ossos avaliada. Um delineamento inteiramente casualizado com cinco tratamentos e três repetições foi utilizado. Os valores de coeficientes de digestibilidade da energia bruta, proteína bruta e aminoácidos e de valores de energia, proteína e aminoácidos digestíveis foram submetidos à regressão linear ou quadrática. Foi observado um aumento linear sobre os valores de proteína digestível e energia digestível à medida que aumentou os níveis de proteína bruta das farinhas de carne. Os coeficientes de digestibilidade aparente médios dos aminoácidos essenciais (incluindo cistina e tirosina) das farinhas de carne e ossos com 30,90; 35,26; 38,06; 41,38 e 44,36% de proteína bruta foram de: 82,21; 86,50; 90,06; 89,94 e 92,61%, respectivamente. Foi observada grande variação entre os CDA da proteína bruta, energia bruta e aminoácidos entre e dentre as farinhas de carne e ossos avaliadas. Com base no conceito de proteína ideal, os aminoácidos mais limitantes na farinha de carne são respectivamente: os aminoácidos sulfurados, a treonina e a isoleucina.viii, 28

Digestibilidade e desempenho de tilápias do Nilo (Oreochromis niloticus) utilizando farinha de penas submetida a diferentes tecnologias de produção

Two experiments were conducted to determine the apparent digestibility coefficients of energy and nutrients as well as apparent absorption coefficients of essential and nonessential amino acids of feather meal and the productive performance of juvenile tilapia fed feather meal submitted to different pressures and different times during the hydrolysis process. In the first experiment, 240 juveniles of Nile tilapia (24.53 ± 3.11 g), were distributed into eight fiberglass tanks of 200 liters each. A reference diet and eight test-diets were elaborated. A completely randomized design in a 2 x 4 factorial arrangement composed by feather meal subjected to two pressures (2.5 and 3.5 kgf/cm²) and four cooking times (10, 20, 30 and 40 minutes), respectively, was used. Except for leucine, glutamic acid, alanine, cystine, glycine, and tyrosine, significant interaction for apparent digestibility coefficients of crude protein gross energy and apparent absorption coefficients of amino acids were observed; where higher apparent digestibility coefficients and apparent absorption coefficients in feather meal submitted to hydrolysis during 20 minutes at 3.5 kgf /cm ² were observed. In the second experiment, during 50 days, 400 fish (6.90 ± 0.20 g), were distributed to 16-500 L plastic aquaria. Four extruded diets with 10% of feather meal were elaborated. A complete randomized design in a 2 x 2 factorial arrangement, composed of two pressures (2.5 and 3.5 kgf/cm²) and two cooking times (20 and 30 minutes) of feather meal was used. No significant differences on weight gain, feed conversion, protein efficiency rate, protein retention and body composition of the fish were observed. It was concluded that considering growth performance, higher apparent digestibility coefficients and apparent absorption coefficients is obtained in feather meal submitted to 20 minutes at 3.5 kgf/cm² during hydrolysis, what is recommended in diets for juvenile Nile tilapia.Dois experimentos foram conduzidos para determinar os coeficientes de digestibilidade aparente da energia e nutrientes; coeficientes de absorção aparente dos aminoácidos essenciais e não essenciais da farinha de penas e, por fim, o desempenho produtivo de juvenis de tilápias do Nilo alimentados com farinha de penas (FP) submetida a diferentes tempos e pressões durante a hidrólise. No primeiro experimento, foram utilizados 240 juvenis de tilápias do Nilo (24,53 ± 3,11 g), distribuídos em oito aquários de fibra de vidro, com capacidade de 200 litros cada. Foi elaborada uma dieta referência e oito dietas teste. O delineamento utilizado foi inteiramente casualizado, em esquema fatorial 2 x 4, composto por FP submetidas a duas pressões (2,5 e 3,5 kgf/cm²) e quatro tempos de cozimento (10, 20, 30 e 40 minutos). Com exceção da leucina, ácido glutâmico, alanina, cistina, glicina e tirosina, foi observada interação significativa para os coeficientes de digestibilidade aparente da proteína bruta, energia bruta e coeficientes de absorção dos aminoácidos, sendo os melhores resultados encontrados nos animais alimentados com dieta contendo FP processada por 20 minutos a 3,5 kgf/cm². No segundo experimento, com duração de 50 dias, foram utilizados 400 peixes (6,90 ±0,20 g), distribuídos em 16 aquários de plástico com capacidade de 500 litros cada. Foram elaboradas quatro dietas extrusadas, com inclusão de 10% de farinha de penas. O experimento foi realizado em esquema fatorial 2 x 2, sendo duas pressões (2,5 e 3,5 kgf/cm²) e dois tempos de cozimento (20 e 30 minutos). Não foram observadas diferenças significativas (P>0,05) sobre o ganho em peso, conversão alimentar, taxa de eficiência proteica, retenção de proteína e composição corporal dos peixes. Concluiu-se que para coeficientes de digestibilidade aparente e de absorção aparente da farinha de penas, assim como para desempenho zootécnico, recomenda-se hidrólise com cozimento durante 20 minutos a 3,5 kgf/cm² para utilização em dietas de juvenis de tilápia do Nilo.[75]

Mathematical modeling for digestible protein in animal feeds for tilapia

The objective of this study was to formulate mathematical models to estimate digestible protein in some animal feeds for tilapia. Literature results of the proximate composition of crude protein, ether extract, and mineral matter, as well as digestible protein obtained in biological assays, were used. The data were subjected to multiple linear stepwise backward regression. Path analysis was performed to measure the direct and indirect effects of each independent variable on the dependent one. To validate the model, the experience used data from independent studies and values obtained from a digestibility trial with juvenile Nile tilapia testing five meat and bone meals, using the Guelph feces collecting system and chromium oxide (III) as an indicator. The obtained model used to estimate digestible protein values (DP) of animal origin is: DP(g kg-1) = -204.15+1.203xCP;R² = 0.953. The path coefficients showed a high direct positive effect (0.900) of crude protein on the digestible protein content. The mineral matter content has an indirect negative effect on protein digestibility (-0.710), reducing the crude protein content and quality

Apparent protein and energy digestibility and amino acid availability of corn and co-products in extruded diets for nile tilapia, oreochromis niloticus

We assessed the nutritional value of corn in extruded diets for Nile tilapia, Oreochromis niloticus, by determining the apparent digestibility coefficients of dry matter, crude protein, and gross energy, and by measuring the apparent availability coefficients (AACs) of essential and non-essential amino acids (AAs) in several corn-based diets. We fed 180 juvenile Nile tilapia a reference diet containing 325.8g/kg crude protein and 4613kcal/kg gross energy or a test diet containing a 70:30 mixture of the reference diet and a test ingredient (whole corn, corn germ, corn germ meal, corn gluten feed, or corn gluten meal). The apparent digestibility coefficients ranged from 56.3 to 96.6% (dry matter), 89.4 to 96.8% (crude protein), and 59.0 to 95.4% (gross energy). The AACs of all AAs exceeded 80% for all diets and were >90% for corn gluten meal. All ingredients showed high levels of apparent digestibility for crude protein and high AACs of AAs. Diets based on whole corn or corn gluten meal showed higher digestibility values for dry matter and gross energy, suggesting that they are preferable choices for Nile tilapia.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Performance and body composition of Nile tilapia fed diets supplemented with AminoGut® during sex reversal period

The present study was to evaluate the effects of the commercial product AminoGut® (Ajinomoto, SP), a source of glutamine and glutamate, on performance and body composition of Nile tilapia fingerlings. A study was conducted with 26,000 Gift strain tilapias, with seven days of age during the sex reversal, with initial weight and length of 0.037±0.09 g and 13.28±0.78 mm. The fish were distributed in a completely randomized design with five treatments and four replications, totaling 1,300 fish/tank of 0,5m3 each one. Control diet was used with approximately 500 g/kg of crude protein and 3,840 kcal/ kg of digestible energy. The AminoGut® was added to the control diet at a ratio of 5, 10, 15 and 20g/kg to replace L-alanine. Each diet was provided 10 times per day at intervals of one hour, from 8:00 until 17:00, for 30 days. No effect was observed on weight gain (p>0.05) in fish fed with increasing levels of Aminogut®. However, a positive linear effect (p<0.05) on feed conversion, protein efficiency ratio and survival of the fish supplemented was verified. The inclusion of Aminogut® up to 20 g/kg improves the feed conversion, protein efficiency ratio and survival, parameters of Nile tilapia during sex reversal