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This study assessed the use of increasing levels of brown propolis extract (BPE) as a growth promoter in Nile tilapia ¢ngerling feeds. In a complete randomized design,75 Nile tilapia ¢ngerlings with 60 days on average and weighing 4.1 AE 0.1g were assigned to 25 aquaria (60 L) and subjected to 5 treatments in 5 repetitions for 30 days. Propolis from Serra do Araripe, Cariri Region, South Ceara Ł State^Brazil was used to produce the BPE. The treatments involved the addition of BPE to feed samples (0.91, 1.83, 2.74 and 3.65 g kg À 1 ) and feed control (without BPE). The ¢nal mean weight and the percentage of weight gain varied quadratically with the increase in BPE (Po0.01), with a maximum of 2.22 g kg À 1 . The other evaluated parameters were not a¡ected by the treatments (P40.05). The level of best performance parameters was 2.22 g kg À 1 , between the levels of 1.83 and 2.74 g BPE kg À 1 feed inclusion. These results indicate the potential to use the brown propolis extract as a growth promoter to Nile tilapia ¢ngerlings.

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RESUMO -Um experimento foi realizado durante 29 dias com o objetivo de avaliar o uso de Saccharomyces cerevisiae (SC) como probiótico em rações para tilápias-do-nilo (Oreochromis niloticus) durante o período de reversão sexual, submetidas a um desafio sanitário. Foram utilizadas 300 larvas de dois dias de idade (8,9 ± 1,02 mg e 0,71 ± 0,09 cm), distribuídas em um delineamento completamente casualizado, com dois tratamentos e seis repetições, em 12 aquários de 50 L. O desafio sanitário foi o fornecimento diário de 0,5 mL de esterco suíno in natura para cada aquário. Os tratamentos constituíram-se de uma ração comercial para a fase de reversão sexual, adicionada (TP) ou não (TT) de 0,1% de S. cerevisiae. As larvas foram alimentadas, à vontade, cinco vezes ao dia e, ao final do experimento, foram contadas, medidas e pesadas. Dois alevinos de cada tratamento foram escolhidos aleatoriamente para retirada dos intestinos e contagem do número de bactérias e coliformes totais. O desempenho e a sobrevivência não foram influenciados pelo tratamento. A SC colonizou o intestino somente dos alevinos do TP. Não foram observadas diferenças significativas quanto ao número de bactérias e coliformes totais por grama de conteúdo intestinal e da água dos aquários. A utilização de Saccharomyces cerevisiae como probiótico em rações promoveu a colonização do intestino de tilápias-do-nilo durante o período de reversão sexual, mas não influenciou o desempenho e a sobrevivência em um sistema de cultivo com desafio sanitário.Palavras-chave: alevinagem, larvicultura, nutrição de peixes, Oreochromis niloticus, promotor de crescimento Saccharomyces cerevisiae as probiotic for Nile Tilapia during the sexual reversion phase under a sanitary challengeABSTRACT -A 29-d experiment was carried out to evaluate the Saccharomyces cerevisiae (SC) as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion phase, under a sanitary challenge. Three hundred 2-d larvae averaging 8.9 ± 1.02 mg and 0.71 ± 0.09 cm were allotted to a completely randomized design with two treatments and six replicates in twelve 50 L-aquaria. Sanitary challenge consisted of a daily supply of 0.5 mL of fresh swine manure. Treatments consisted of a commercial diet for the sexual reversion of tilapia, with (TP) or without (TT) 0.1% of S. cerevisiae. The larvae were fed ad libitum five times a day. At the end of experiment, the fries were counted, measured and weighed. Two fries of each treatment were randomly chosen for gu removal and counting of the number of bacteria and total coliforms. No treatment effect on performance and survival was observed. Only the intestine of TP fries was colonized by SC. No significant differences were observed for bacteria and total coliforms per g of intestinal content and aquarium water. The use of Saccharomyces cerevisiae as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion period resulted in intestine settling with no effect on performance and survival, in a system of culture with...

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The objective of this work was to evaluate the use of crude glycerol as an energy source to replace corn, in diets for Nile tilapia (Oreochromis niloticus) in the fattening stage. Two hundred Nile tilapia (190±4.5 g) were distributed in 20 tanks, in a completely randomized design. The treatments consisted of crude glycerol at 0, 60, 120, 180, and 240 g kg-1, to replace the dietary levels of corn, in order to maintain a constant digestible energy. Fish productive performance and the chemical composition of the fillet were evaluated. Histological analyses of the hepatopancreas, intestine, and visceral fat were also carried out. Crude glycerol had no effect on the performance parameters; however, it caused a quadratic reduction of visceral fat. There was an increase in the moisture and a decrease in the ether extract of the fillet. A linear effect on the blood glucose levels was verified in fish fed the diet without glycerol, and the peak occurred at 90 min. There were no differences for measurements of intestinal villi height and hepatocyte area. Crude glycerol can replace corn in diets for Nile tilapia in the fattening stage, without adversely affecting fish metabolism, productive performance, or survival.