Feed training of giant trahira fingerlings fed diets containing different levels of vitamin C

Abstract

-The objective of this work was to evaluate suplemenation of vitamin C during feed training of giant trahira fingerlings. An experiment was established in a complete random design with seven treatments (0.0, 17.5, 52.5, 87.5, 122.5, 175.0 and 350.0 mg vitamin C/kg diet) and four repetitions. Giant trahira fingerlings (2.8 ± 0.2 cm) were distributed in 6-L aquaria at the density of 6 fish/L. A basal diet was formulated with 44.0% of crude protein and vitamin C and bovine heart were added in it daily. After 20 days, biometry of fish for evaluation of weight and length gains, rates of survival and cannibalism and uniformity of final length and for macroscopic observations of clinical signs of deficiency or excess of vitamin was carried out. After biometry evaluation, ten fish from each tested diet were collected for analysis of the fatty acid profile which was compared to profile of fish at the same life stage fed forage fish collected from breeding fishponds. Data on growth performance and fatty acid profiles were submitted to analyses of polynomial regression and uniformity of the final length was evaluated by the Bartlett test. There was a significant difference only for uniformity in final length and fatty acid profile of the carcass. Supplementation with 52.5 mg vitamin C/kg diet provided a greater uniformity of the final length of the fish. Fish from breeding fishponds presented lower concentration of PUFA (polyunsaturated fatty acids) and higher concentration of saturated fatty acids compared to fish trained to accept dry diets. com 44,0% proteína bruta, e diariamente foi adicionada vitamina C e coração bovino. Após 20 dias, realizou-se biometria dos peixes para avaliação do ganho de peso e do comprimento, das taxas de sobrevivência e canibalismo e da uniformidade do comprimento final e para observações macroscópicas de sinais clínicos de deficiência ou excesso da vitamina. Após a biometria, dez peixes de cada dieta testada foram coletados para análise do perfil de ácidos graxos e este perfil foi comparado ao perfil de peixes, na mesma fase de vida, alimentados com peixes forrageiros coletados de viveiros de criação. Os dados de desempenho produtivo e perfil de ácidos graxos foram submetidos a análise de regressão polinomial e a uniformidade do comprimento final avaliada pelo teste de Bartlett. Houve diferença significativa apenas para a uniformidade em comprimento final e perfil de ácidos graxos da carcaça. A suplementação com 52,5 mg de vitamina C/kg de ração proporcionou maior uniformidade do comprimento final dos peixes. Os peixes dos viveiros de criação apresentaram menor concentração de PUFA (polyunsaturated fatty acids) e maior de ácidos graxos saturados em comparação aos peixes condicionados a aceitar dietas secas.Palavras-chave: canibalismo, Hoplias lacerdae, peixes carnívoros, perfil lipídico, uniformidade em comprimento Revista Brasileira de Zootecnia

Feed training of juvenile giant trahira under different light intensities

“…Feed training was conducted using food pellets following methods proposed by Luz et al (2002), with modifications to the time of transition diets (Kasai et al, 2011) (Tables 1 and 2). …”

Saline water for juvenile giant trahira during feed training

“…The ability of salt to act as a mitigator of stress during transport and recovery has been reported by several authors (Carneiro & Urbinati, 2001;Tsuzuki et al, 2001;Gomes et al, 2003), along with its role in disease prevention (Altinok & Grizzle, 2001b;Garcia et al, 2007), which is particularly useful, given the common occurrence of disease in fish under stress conditions. High survival rates were also observed during feed training at 4 g of salt L -1 (Kasai et al, 2011). Salinity gradients of up to 6 g of salt L -1 did not negatively affect the survival rate of other species of freshwater fish (Altinok & Grizzle, 2001a;Luz & Santos, 2010).…”

“…The technique of feed training consisted of a gradual transition of ingredients using mixtures of bovine heart (H) and commercial ration (F) following the protocol described by Kasai et al (2011): 20F:80H (diet 1); 40F:60H (diet 2); 60F:40H (diet 3); 80F:20H (diet 4); and 100%F (diet 5). Each diet was offered for 4 days.…”

Suplementação de vitamina C em dietas para juvenis de trairão

“…Após Para a análise dos ácidos graxos da carcaça dos peixes, as amostras de cada tratamento foram homogeneizadas e separadas em triplicata para extração dos lipídeos (Folch et al, 1957), com subsequente saponificação e esterificação (Hartman & Lago, 1973). Após estes procedimentos, determinou-se o perfil de ácidos graxos por cromatografia gasosa, em aparelho GC 17A (Shimadzu do Brasil Ltda., São Paulo, SP), equipado com detector de ionização de chama, injetor split e coluna cromatográfica de sílica fundida SP-2560, (Supelco Distribuidora, São Paulo, SP) de 100 m e 0,25 mm de diâmetro interno.…”

“…Utilizou-se a densidade de estocagem de 2,5 peixes por litro. Previamente, realizou-se o condicionamento alimentar dos peixes para aceitarem dietas secas, segundo metodologia proposta por Luz et al (2002) e adaptada por Kasai et al (2011). Durante a fase de condicionamento alimentar, utilizou-se o mesmo delineamento e as mesmas dietas da fase experimental.…”