Resumo
O presente estudo foi conduzido com o objetivo de determinar a atrato-palatabilidade para juvenis de tilápia do Nilo alimentados com rações contendo proteínas hidrolisadas seca e líquida e níveis do aromatizante Atractus Aqva® incluídos em substituição a farinha de peixe. Para determinar o comportamento alimentar dos peixes referente aos hidrolisados seco foram utilizados quatro juvenis de tilápia do Nilo com peso médio de 2,90 ± 0,01 g, distribuídos em aquários com volume de 10 litros. Foram elaboradas quatro dietas experimentais contendo 5% de inclusão de proteína hidrolisada de frango (PHF), proteína hidrolisada de fígado suíno (PHS), proteína hidrolisada de penas (PHP) e o tratamento controle (FPE) contendo farinha de peixe. Os animais foram adaptados às condições e dietas experimentais por quinze dias. Os peixes foram alimentados quatro vezes ao dia, para cada alimentação foram fornecidos 20 peletes por peixe e o ensaio teve a duração de oito dias. Na avaliação do comportamento alimentar dos peixes referente ao aromatizante Atractus Aqva® foram utilizados cinco juvenis de tilápia do Nilo com peso médio de 2,58 ± 0,27g, distribuídos em cinco aquários com volume de 10 litros. Foram elaboradas cinco dietas experimentais contendo 0,25% (A25); 0,50% (A50) e 0,75% (A75) de inclusão de aromatizante, controle positivo contendo farinha de peixe (FPE) e controle negativo sem farinha de peixe (SPE). Os animais foram adaptados às condições e dietas experimentais por oito dias. Os peixes foram alimentados quatro vezes ao dia, para cada alimentação ao longo do dia foram fornecidos 30 peletes por peixe e o ensaio teve a duração de oito dias. Para determinar o comportamento alimentar dos peixes referente aos hidrolisados líquido foram utilizados cinco juvenis de tilápia do Nilo com peso médio de 2,51± 0,13 g, distribuídos em aquários com volume de 10 litros. Foram elaboradas cinco dietas experimentais contendo 5% de inclusão de farinha de peixe (FPE), proteína hidrolisada líquida de mucosa suína (PHM), proteína hidrolisada líquida de frango (PHF), óleo de peixe líquido (OPE) e uma dieta sem farinha de peixe (SPE). Os animais foram adaptados às condições e dietas experimentais por dez dias. Os peixes foram alimentados cinco vezes ao dia, para cada alimentação ao longo do dia foram fornecidos 20 peletes por peixe e o ensaio teve a duração de doze dias. Em ambos os ensaios, os delineamentos experimentais foram inteiramente casualizados e foram observados os comportamentos alimentares referentes ao tempo de captura do primeiro pelete, número de rejeição do pelete, número de aproximação sem haver a captura do pelete e número de peletes consumidos de cada alimentação por meio de filmagens durante três minutos com uma câmera digital. Os dados obtidos foram submetidos à análise de variância paramétrica (ANOVA) e em caso de efeito significativo (P < 0,05), foi realizado o teste de comparação múltipla de Tukey em nível de 5% de significância. Quanto aos hidrolisados secos a PHF influenciou (P < 0,05) positivamente o consumo de ração e número de rejeição dos peletes após captura quando comparado à dieta PHP, não diferindo dos demais (P > 0,05). A PHF proporcionou maior valor numérico para o índice de palatabilidade, com 10,82%, aumento de 17% no consumo de ração final e apresentou número de rejeição 6,89 vezes menor em relação à dieta FPE. Referente aos níveis de aromatizante, o A75 apresentou diferenças significativas (P < 0,05) para o comportamento alimentar referente ao número de aproximação sem captura do pelete e maior índice de palatabilidade, com 10,49%, aumento de 13% no consumo de ração final, 23,13% menor rejeição dos peletes e apresentou 3,3 vezes menor número de aproximação sem captura dos peletes em relação à dieta FPE. Quanto aos hidrolisados líquidos, nenhum parâmetro observado apresentou diferença significativa (P > 0,05). Todas as dietas apresentaram índice de palatabilidade negativo comparando-se com FPE. A SPE proporcionou um índice de palatabilidade de -2,34%, OPE índice de -6,48%, PHM índice de -10,80% e PHF índice de -15,21%. As dietas PHF e PHM diminuíram o consumo de peletes em comparação com a FPE em aproximadamente 28% e 20%, respectivamente. Assim, com base nos resultados obtidos, para juvenis de tilápia do Nilo (Oreochromis niloticus) em substituição à farinha de peixe recomenda-se a PHF seca e A75, a utilização dos hidrolisados na forma de mucosa suína e frango na forma líquida não apresentaram bons resultados de atrato-palatabilidade.
The present study was performed with the aim of determining the compelling palatability for Nile tilapia juveniles fed with diets containing dry and liquid protein hydrolysates and inclusion levels of the flavoring Atractus Aqva® in replacement of fishmeal. In order to determine the fishs behavior concerning dry hydrolysates, four Nile tilapia juveniles (2.90 ± 0.01 g) were used, distributed in 10L tanks. Four experimental diets containing 5% inclusion of poultry protein hydrolysate (PHF), swine liver protein hydrolysate (PHS), feather protein hydrolysate (PHP) and the fishmeal (FPE, control treatment) were elaborated. The animals were adapted to the experimental conditions for fifteen days before the experiments. The experiment lasted for eight days, and fish were fed four times a day with a supply of 20 pellets per animal. Regarding the evaluation of the feeding behaviors of fish fed with diets containing Atractus Aqva®, five juvenile fish (2.58 ± 0.27 g) were distributed in 10L tanks, and five experimental diets were made with 0.25% (A25); 0.50% (A50); and 0.75% (A75) of flavoring inclusion, besides the positive control with fishmeal (FPE) and the negative control without fishmeal (SPE). The animals were adapted to the experimental conditions for eight days, and were fed four times a day, with 30 pellets being offered per feeding event. The experiment lasted for eight days. In order to determine the feeding behavior of fish concerning the liquid hydrolysates, five Nile tilapia juveniles (2.51 ± 0.13 g) were also distributed in 10L tanks. The following diets were elaborated: a diet containing a 5% inclusion level of fishmeal (FPE); liquid protein hydrolysate of porcine mucosa (PHM), poultry (PHF), fish oil (OPE) and a diet without fishmeal (SPE). The animals were also adapted to the experimental conditions, for ten days, and were fed five times a day, which in each feeding event 20 pellets were supplied per fish. This experiment lasted for twelve days. In both essays, the experimental design was completely randomized and the feeding behaviors regarding time to capture first pellet, number of pellet rejections, number of approximations without capturing the pellet and number of consumed pellets were observed in each feeding by means of three-minute footages made with a digital camera. The obtained data were submitted to a parametric variance analysis (ANOVA) and in case of significant effect, the multiple comparison test of Tukey was performed at a 5% significance level. Regarding the dry hydrolysates, PHF has positively influenced feed consumption and pellets rejection after capture (P < 0.05) in comparison to PHP, not differing from the other diets (P > 0.05). The diet PHF provided the highest palatability index (10.82%), representing a 17% increase in final feed consumption and a 6.89 times lower rejections in relation to FPE. Concerning the inclusion levels of the flavoring, A75 presented significant differences (P < 0.05) on the number of approximations without capturing the pellet and a high palatability index of 10.49%, besides a 13% increase in the final feed consumption, a 23.13% lower pellets rejection and a 3.3 times higher approximations without capturing pellets in relation to FPE. Regarding liquid hydrolysates, none of the observed parameters were statistically different (P > 0.05), and all diets presented negative palatability indexes in comparison to FPE. The SPE diet had a palatability index of -2.34%, OPE -6.84%, PHM -10.80%, and PHF a -15.21% index. Both PHF and PHM reduced the pellet consumption in comparison to FPE in approximately 28% and 20%, respectively. Thus, based on the obtained results the replacement of fishmeal in Nile tilapia juvenile diets can be achieved using both dry PHF and A75, whilst using liquid hydrolysates is not recommended, as they did not present good compelling palatability results.
Resumo
The replacement and growth of 311 primary feathers of eight captive male rock pigeons, Columba livia Gmelin, 1789 were monitored daily. Feather replacement was recorded in all months, but the primaries 1 to 5 (innermost primaries) were replaced mostly from September to December, whereas the primaries 6 to 10 (outermost primaries) were more frequently replaced from January to August. Each primary was held in plumage from six to fifteen months, but the lifetime of the outer feathers was longer than that of the inner feathers. A new primary emerges two or three days after its predecessor has been dropped, but the primaries replacing the feathers accidentally lost during bird handling emerge only after about eight days. The average growth period of a primary ranged from 21 to 37 days, with the larger and outermost feathers exhibiting a longer growth period. A constant average growth rate of 4 to 5 mm/day was found for all primaries until the last two days of growth, when the growth rate of the feathers became progressively slower. Bilateral symmetry in the primary replacement, when the same feather is replaced simultaneously in both wings, was not significant (22.2%) in the birds monitored in this study.
Resumo
The replacement and growth of 311 primary feathers of eight captive male rock pigeons, Columba livia Gmelin, 1789 were monitored daily. Feather replacement was recorded in all months, but the primaries 1 to 5 (innermost primaries) were replaced mostly from September to December, whereas the primaries 6 to 10 (outermost primaries) were more frequently replaced from January to August. Each primary was held in plumage from six to fifteen months, but the lifetime of the outer feathers was longer than that of the inner feathers. A new primary emerges two or three days after its predecessor has been dropped, but the primaries replacing the feathers accidentally lost during bird handling emerge only after about eight days. The average growth period of a primary ranged from 21 to 37 days, with the larger and outermost feathers exhibiting a longer growth period. A constant average growth rate of 4 to 5 mm/day was found for all primaries until the last two days of growth, when the growth rate of the feathers became progressively slower. Bilateral symmetry in the primary replacement, when the same feather is replaced simultaneously in both wings, was not significant (22.2%) in the birds monitored in this study.
Resumo
The replacement and growth of 311 primary feathers of eight captive male rock pigeons, Columba livia Gmelin, 1789 were monitored daily. Feather replacement was recorded in all months, but the primaries 1 to 5 (innermost primaries) were replaced mostly from September to December, whereas the primaries 6 to 10 (outermost primaries) were more frequently replaced from January to August. Each primary was held in plumage from six to fifteen months, but the lifetime of the outer feathers was longer than that of the inner feathers. A new primary emerges two or three days after its predecessor has been dropped, but the primaries replacing the feathers accidentally lost during bird handling emerge only after about eight days. The average growth period of a primary ranged from 21 to 37 days, with the larger and outermost feathers exhibiting a longer growth period. A constant average growth rate of 4 to 5 mm/day was found for all primaries until the last two days of growth, when the growth rate of the feathers became progressively slower. Bilateral symmetry in the primary replacement, when the same feather is replaced simultaneously in both wings, was not significant (22.2%) in the birds monitored in this study.