Contaminação fúngica em rações para camarões cultivados

Abstract

The objective of this study was to evaluate the quality of the diet, provided to cultivated shrimps, through fungi counts. One hundred forty four feed samples were collected in four shrimp farms in a randomized way and letters were used to designate them. The experimental design was completely randomized in factorial scheme 2 x 3 x 2 (periods of the year, cultivation phases and condition of the packing and properties), with three repetitions of 100 g feed. Brackets of the dilutions 10-1 to 10-3 were sowed in Petri plates containing Dichloran Rose Bengal Cloranfenicol and they were incubated by seven days to 28 ºC. The results were transformed in log 10(x+1) and they were submitted to the test of Duncan, with p<0,05. Considering all samples analyzed, 136 (94,4 %) presented contamination by molds. It was observed the existence of fungi spores, even in samples taken from intact packing. The countings during the dry period oscillated from 1,43 to 2,72 UFC/g and during the rainy one from  2,10 to 5,95 UFC/g, presenting, in this last period,  a significant difference among shrimp farms, cultivation phases and, in the two farms, packing condition has also shown to be different. Therefore, it was possible to conclude that  feed used has presented fungi spores and that the climatic conditions and packing  ones favor the feed contamination.Objetivou-se neste trabalho avaliar a qualidade da ração, fornecida a camarões cultivados, pormeio da contagem de fungos. Foram coletadas 144 amostras de ração em quatro propriedadescarcinicultoras randomicamente sorteadas e designadas por letras. O delineamento experimentalfoi inteiramente casualizado, em esquema fatorial 2 x 3 x 2 x 4 (períodos do ano, fases de cultivo,condição da embalagem e propriedades), com três repetições, representadas por amostras de100 g de ração. Alíquotas das diluições 10-1 a 10-3 foram semeadas em placas de Petri contendoDichloran Rose Bengal Cloranfenicol e incubadas por sete dias a 28 ºC. Os dados passaram portransformação logarítmica (log 10(x+1)) e foram submetidos à análise de variância. Para comparaçãodas médias, realizou-se o teste Duncan, com p<0,05. Das amostras analisadas, 136 (94,4 %)apresentaram contaminação por fungos. Foi verificada a ocorrência de esporos de fungos,mesmo em amostras obtidas de embalagens íntegras. As contagens no período seco oscilaramentre 1,43 e 2,72 UFC/g e no chuvoso entre 2,10 e 5,95 UFC/g, havendo, neste período, diferençasignificativa entre propriedades, fases de cultivo e, em duas propriedades, houve diferença quantoà condição das embalagens. Conclui-se que as rações utilizadas apresentam contaminação poresporos de fungos e que as condições climáticas e de manipulação das embalagens favorecema contaminação da ração.  Fungi contamination in feed to cultivated shrimpAbstractThe objective of this study was to evaluate the quality of the diet, provided to cultivated shrimps,through fungi counts. One hundred forty four feed samples were collected in four shrimp farms in arandomized way and letters were used to designate them. The experimental design was completelyrandomized in factorial scheme 2 x 3 x 2 (periods of the year, cultivation phases and condition of thepacking and properties), with three repetitions of 100 g feed. Brackets of the dilutions 10-1 to 10-3 weresowed in Petri plates containing Dichloran Rose Bengal Cloranfenicol and they were incubated byseven days to 28 ºC. The results were transformed in log 10(x+1) and they were submitted to the test ofDuncan, with p<0,05. Considering all samples analyzed, 136 (94,4 %) presented contamination bymolds. It was observed the existence of fungi spores, even in samples taken from intact packing. Thecountings during the dry period oscillated from 1,43 to 2,72 UFC/g and during the rainy one from 2,10to 5,95 UFC/g, presenting, in this last period, a significant difference among shrimp farms, cultivationphases and, in the two farms, packing condition has also shown to be different. Therefore, it waspossible to conclude that feed used has presented fungi spores and that the climatic conditionsand packing ones favor the feed contamination.