Fósforo na alimentação de pacu (Piaractus mesopotamicus)

Abstract

RESUMO -Objetivou-se avaliar o uso de fósforo na dieta de juvenis de pacu (Piaractus mesopotamicus) sobre a qualidade da água, o desempenho zootécnico, o rendimento corporal e a composição química da carcaça. Foram utilizados 100 juvenis com peso médio inicial de 25,9±1,32 g, distribuídos em delineamento inteiramente ao acaso, em 20 tanques de fibra de vidro, com cinco tratamentos e quatro repetições. Os peixes foram alimentados quatro vezes ao dia, às 8; 11; 14 e 17 h, com dietas extrusadas contendo 0,40; 0,55; 0,70; 0,85 e 1,0% de fósforo total. Não foram observadas diferenças nos parâmetros de qualidade de água, com exceção da concentração de ortofosfato na água, que apresentou aumento linear. Os parâmetros de desempenho zootécnico, rendimento corporal e composição química da carcaça não diferiram entre os níveis de suplementação de fósforo na dieta. A utilização de 0,40% de fósforo total atende às exigências de fósforo de juvenis de pacu (Piaractus mesopotamicus), além de disponibilizar menor concentração de ortofosfato da água.Palavras-chave: exigência nutricional, mineral essencial, peixe nativo, qualidade de água Phosphorus in feed for pacu (Piaractus mesopotamicus)ABSTRACT -The objective of the present research was to evaluate phosphorus in diet for pacu (Piaractus mesopotamicus) juveniles on water quality, livestock performance, body yield and carcass chemical composition. A total of 100 juveniles, 25.9±1.32 g average weight were randomly assigned into 20 fiberglass tanks, with five treatments and four replications. The fish were fed four times a day (8 and 11 a.m.; 2 and 5 p.m.), with extruded diets containing 0.40; 0.55; 0.70; 0.85 and 1.0 % total phosphorus. No differences were observed in water quality parameters, except for the concentration of orthophosphate in water, which presented linear increase. The parameters livestock performance, body yield and carcass chemical composition showed no differences for the levels of supplementation of phosphorus in diet. The use of 0.40% total phosphorus meets the requirements of phosphorus for pacu (Piaractus mesopotamicus) juveniles, in addition to releasing lower concentration of orthophosphate in water.

Apparent digestibility of pacu (Piaractus mesopotamicus) diets containing different levels of phosphorus

“…However, phosphorous values in the carcasses were higher in the present study (approximately 0.7%) than those observed by Signor et al (2011), who observed values of approximately 0.4%. It is important to highlight that the fish in the two studies were of different ages and weights.…”

“…Similar data were observed by Furuya et al (2008), who studied the availability of this mineral for tilapia and indicated that the excretion of fecal phosphorus per kg of produced fish increased linearly with available phosphorus levels of 0.25, 0.35, 0.45 and 0.55%. The data from the present study are also in accordance with Oliva-Teles and Pimentel-Rodrigues (2004), which shows that diets with available phosphorus values above the requirements for pacu (0.4% to 0.6% according to Signor et al (2011) andDiemer et al (2014), respectively) are not required. However, to obtain formulations with levels below 0.6%, feeds with large quantities of animal-derived ingredients, which often enjoy high availability and low cost in the market and include meat and bone meal and other by-products of agro-industrial meat processers, should be avoided.…”

“…The water content, crude protein and mineral matter values were close to those observed by Signor et al (2011), who evaluated the chemical composition of pacu carcasses that were fed diets with different phosphorus levels ranging from 0.4 to 1.0%. However, phosphorous values in the carcasses were higher in the present study (approximately 0.7%) than those observed by Signor et al (2011), who observed values of approximately 0.4%.…”

“…According to Furuya et al (2001), minerals available in the water are insufficient to meet the high levels of dietary requirements imposed by production systems; therefore, these nutrients, especially phosphorus, must be supplemented through the diet. According to Signor et al (2011) andDiemer et al (2014), the total dietary phosphorus requirement for pacu ranges from 0.4% to 0.6%.…”

Dietary available phosphorus requirement for tambaqui,Colossoma macropomum, juveniles based on growth, haematology and bone mineralization

“…To the best of our knowledge, there are just two studies with Pacu ( Piaractus mesopotamicus ), a Neotropical fish from the same family as tambaqui (Signor et al . ; Diemer et al . ), and until now, there is no report with tambaqui.…”