Regulação da ingestão protéica na tilápia do Nilo, Oreochromis niloticus

Abstract

RESUMO -Estudou-se a habilidade de juvenis de tilápia do Nilo, Oreochromis niloticus, em regular a ingestão protéica. Mil exemplares com peso e comprimento de 13,93g ± 0,87g e 8,8cm ± 0,47cm, respectivamente, revertidos sexualmente, foram distríbuídos em oito grupos de 125 peixes, em aquários de 1.000 L com renovação contínua de água e dotados de dois alimentadores de demanda. Duas rações isoenergéticas (2.800 kcal/kg) contendo, respectivamente, 40% e 15% PB foram oferecidas diariamente, ad libitum, em combinações que caracterizaram quatro tratamentos: A: ração de 15% PB de um lado e de 40% PB do outro do aquário; B: idêntico ao tratamento A com inversão dos lados; C: ração de 15% PB fornecida em dois alimentadores; e D: ração de 40% PB fornecida em dois alimentadores. O delineamento em quadrado latino permitiu que os peixes fossem submetidos a cada tratamento durante quatro fases de 15 dias (I, II, III e IV). Entre as fases, houve intervalo de uma semana, quando os peixes receberam dieta contendo 30% PB nos dois alimentadores. O consumo alimentar dos peixes, registrado diariamente, não diferiu significativamente entre os tratamentos A e B. Porém, quando foram apresentadas simultaneamente as dietas contendo mesmo teor de PB (Tratamentos C e D), observou-se consumo significativamente maior da ração contendo 15% de PB (Tratamento C). O ajuste em porcentagem da proteína ingerida pelos peixes revelou média de 24% de PB. Os resultados confirmaram a hipótese de que a tilápia do Nilo apresenta habilidade em regular a ingestão dietética protéica por meio de livre escolha.Palavras-chave: comportamento alimentar, livre escolha, Oreochromis niloticus, proteína, tilápia do Nilo Hability of Protein Intake Regulation in Nile Tilapia, Oreochromis niloticusABSTRACT -The free-choice feed and regulation of protein intake were investigated in juveniles reverted males of tilápia do Nilo, Oreochromis niloticus. During the experiment 1000 fish (reverted males) with similar weigth and length were maintained in eight aquariuns supplied with recirculated water (groups of 125 fish each aquarium). Fish were fed by demand-feeders, containing the two experimental diets, formulated to contain 15% and 40% protein each and distributed in four treatments (A: 15% protein diet on one hand and 40% protein diet on the other hand, B: alike in A, therefore with an inversion on both hands, C: the two feeders supplied with 15% protein diet, D the two feeders supplied with 40% protein diet) The Latin Square was the estatistical method used for the experiment, and the treatments were distributed into four stages (I, II, III and IV). A one week stop after each stage was stipulated and the fish received a 30% protein diet. The results showed that no differences about the intake was detected between fish fed by diets containing 15% and 40% protein in the same aquarium. However, with same diets in the tanks ( Treatment C and D), the animals that were fed with the 15% protein diet showed better feed intake. The percentage of regulated protein during the exper...

Effect of temperature on the predation rate of the pearl cichlid (Geophagus brasiliensis) on the channeled applesnail (Pomacea canaliculata)

“…While the fish primarily feed to meet their energy needs (Pereira-Da- Silva et al, 2004), the voluntary intake of food can be influenced by the amount of energy in the diet. Lipids are good energy source for fish, containing 2.25 times more energy than carbohydrates.…”

Influence of Tryptophan supplemented diets on self-balancing, food intake and growth performance of juvenile and adult Nile tilapia

“…Furthermore, it has been demonstrated that fish prefer certain pellet formats, textures, smells and flavors (Botero, 2004). Fish were also found capable of regulating the intake of certain nutrients and ingredients (protein levels, different oils and protein sources, among others) in selfbalancing and food selection studies, bringing us ever closer to their behavior, feeding preferences and nutritional requirements (Pereira-da-Silva & Pezzato, 1999Pereira-da-Silva et al, 2004;Bordinhon, 2008).…”

“…This type of study of evaluating feeding habits and ingestion consists of offering a control diet and a diet supplemented with the nutrient or ingredient to be tested, which may be an amino acid, energy or protein, among others. Feed intake is then observed for several days between the control and the tested diet to evaluate the parameter to be tested, which is, usually, productive performance parameter in the juvenile phase (Pereira-da-Silva et al, 2004;Bordinhon, 2008).…”