Freqüência alimentar na larvicultura do trairão (Hoplias lacerdae)
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Data
2005-10-01
Autores
Luz, Ronald Kennedy [UNESP]
Portella, Maria Célia [UNESP]
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ISSN da Revista
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Editor
Sociedade Brasileira de Zootecnia
Resumo
O experimento foi realizado com o objetivo de se desenvolver estratégias de manejo alimentar durante a larvicultura de trairão. Larvas com oito dias de vida foram contadas individualmente e alojadas na densidade de 30 larvas/L em 20 unidades experimentais com volume útil de 5 L cada. As larvas foram submetidas a quatro tratamentos de freqüência alimentar: F1 - uma vez ao dia; F2 - duas vezes ao dia; F3 - três vezes ao dia; F4 - quatro vezes ao dia, cada um com cinco repetições. A alimentação foi fornecida na mesma quantidade em todos os tratamentos. Para avaliação do crescimento dos animais, foram realizadas biometrias a cada cinco dias. Após 15 dias sob os tratamentos, quando os animais estavam com 23 dias de vida, o experimento foi encerrado, avaliando-se também as taxas de sobrevivência, de mortalidade, de canibalismo e de resistência ao estresse. Na primeira avaliação biométrica, aos 13 dias de vida, não foram encontradas diferenças significativas no crescimento das larvas submetidas às diferentes freqüências alimentares. No entanto, aos 18 e 23 dias de vida, os animais do tratamento F1 apresentaram as menores médias de comprimento e peso. Não foi encontrado efeito significativo da freqüência alimentar sobre as taxas de crescimento específico durante a larvicultura. As diferentes freqüências de alimentação impostas não influenciaram as taxas de sobrevivência, de mortalidade, de canibalismo e de resistência ao estresse, destacando-se as elevadas taxas de sobrevivência (acima de 93%) obtidas durante o período de larvicultura. Portanto, pelo menos durante a criação inicial (até 23 dias de vida), as larvas de trairão podem receber manejo mais simplificado, com fornecimento de alimento apenas duas vezes ao dia, sem prejuízo ao desenvolvimento e à produção de animais.
The effects of feeding management strategies on larval rearing of trairao were evaluated in this trial. Eight-d old larvae were counted and stocked in 20 experimental containers (units with volume of 5 L each), with constant aeration and temperature. The stocking density was 30 larvae/L. The following treatments (feeding frequency) were used: F1 - once a day, F2 - twice a day, F3 - three times a day, F4 - four times a day, each with five replicates. Feeding rate was equal for all treatments. In order to evaluate the animal growth, some samples were collected every five days. At the end of the experiment, after 23 days, the survival, mortality, rates of cannibalism and stress resistance were also evaluated. No significant difference was observed among the growth parameters at 13 days. However, after 18 and 23 days, F1 treatment showed the lowest length and weight averages. No differences of larval specific growth rate due to the feeding frequencies were observed. No effects of feeding frequency on rates of survival, mortality, cannibalism and stress resistance were detected. The survival rates showed the highest values (93%) during the experiment. Thus, trairao larvae can be fed only twice a day, with no changes on growth, at least during the initial rearing (first 23 days).
The effects of feeding management strategies on larval rearing of trairao were evaluated in this trial. Eight-d old larvae were counted and stocked in 20 experimental containers (units with volume of 5 L each), with constant aeration and temperature. The stocking density was 30 larvae/L. The following treatments (feeding frequency) were used: F1 - once a day, F2 - twice a day, F3 - three times a day, F4 - four times a day, each with five replicates. Feeding rate was equal for all treatments. In order to evaluate the animal growth, some samples were collected every five days. At the end of the experiment, after 23 days, the survival, mortality, rates of cannibalism and stress resistance were also evaluated. No significant difference was observed among the growth parameters at 13 days. However, after 18 and 23 days, F1 treatment showed the lowest length and weight averages. No differences of larval specific growth rate due to the feeding frequencies were observed. No effects of feeding frequency on rates of survival, mortality, cannibalism and stress resistance were detected. The survival rates showed the highest values (93%) during the experiment. Thus, trairao larvae can be fed only twice a day, with no changes on growth, at least during the initial rearing (first 23 days).
Descrição
Palavras-chave
freqüência de alimentação, Hoplias lacerdae, larvicultura, trairão, feeding frequency, Hoplias lacerdae, larvae rearing, trairao
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 34, n. 5, p. 1442-1448, 2005.