Dietary total phosphorus requirement of juvenile yellow catfish Pelteobagrus fulvidraco

Abstract

The present experiment was conducted to determine the dietary total phosphorus requirement of juvenile yellow catfish Pelteobagrus fulvidraco. Six diets with increasing dietary phosphorus concentration (0.43, 0.55, 0.78, 0.90, 1.05 and 1.18% of dry matter, respectively) were fed to triplicate groups of 20 fish each (mean initial body weight, 2.68 ± 0.08 g, mean ± SD) to apparent satiation for 7 weeks. Weight gain and specific growth rate (SGR) increased with increasing dietary phosphorus level from 0.43 to 0.90% and then declined over dietary phosphorus level of 0.90% (P \ 0.05). Phosphorus retention increased with increasing dietary phosphorus level from 0.43 to 0.55% and then declined over dietary phosphorus level of 0.55% (P \ 0.05). Dietary phosphorus levels significantly influenced whole body crude protein and ash contents (P \ 0.05), but not whole body lipid content (P [ 0.05). Vertebrae phosphorus content increased with dietary phosphorus level from 0.43 to 0.78% (P \ 0.05) and then plateau over the level of 0.78% (P [ 0.05). Dietary phosphorus level significantly influenced condition factor, viscerosomatic index and hepatosomatic index (P \ 0.05). The relationship between SGR and whole body ash content against dietary phosphorus levels could be expressed as a second-order polynomial equation and the points of 0.89 and 0.85% were considered to be the optimal dietary total phosphorus level, respectively. Based on broken-line analysis of vertebrae phosphorus content, the minimal dietary total phosphorus requirements for maintaining maximum phosphorus storages were estimated to be 0.76% phosphorus.

Dietary manganese requirement of juvenile yellow catfish Pelteobagrus fulvidraco, and effects on whole body mineral composition and hepatic intermediary metabolism

“…At present, different parameters have been used to determine mineral requirement in fish, including growth performance (Lin et al, 2010;Pan et al, 2008;Tan et al, 2011), feed utilization (Luo et al, 2010, tissue mineral concentration (Lin et al, 2008;Luo et al, 2010;Maage et al, 2000;Pan et al, 2008;Tan et al, 2011) and hepatic Mn-SOD activity (Lin et al, 2008). Our present study indicated that Mn requirements obtained from WG, PER and hepatic Mn-SOD activities were similar, whose values were 5.5, 5.6 and 6.4 mg kg − 1 diet, respectively.…”

“…Recently, in our laboratory, studies have been conducted to determine several mineral requirements for the fish species, including dietary phosphorus (Luo et al, 2010), copper and zinc requirement . We also evaluated the effect of dietary cadmium levels (Tan et al, 2010b) on growth performance and hepatic intermediary metabolism for this fish species.…”

Effect of dietary phosphorus levels on growth and body composition of crucian carp, Carassius auratusunder indoor and outdoor experiments

“…However, 107 days of late P deficiency did not affect final length and weight significantly (Deschamps et al 2014). The initial body weight in the present study was about 40~45 g, while in many of the previous studies, fish used in the experiments were less than 10 g (Roy & Lall 2003;Mai et al 2006;Zhang et al 2006;Shao et al 2008;Sukumaran et al 2009;Luo et al 2010;Xie et al 2011;Yuan et al 2011;Liang et al 2012;Yu et al 2013), which should be more sensitive to P supplement. Thirdly, a relatively low growth rate may result in low P requirement, for rapid growing fishes had higher diet P requirement (Benstead et al 2014) .…”

Modeling phosphorus metabolism in fish species: an example for juvenile yellow catfish, Pelteobagrus fulvidraco

“…The inflection point of the selected logistic model indicates the maximum change rate of dissolved P waste discharge relative to dietary P avail% occurring at P avail% = 1.00 and dissolved P waste = 5 g kg -1 feed, probably denoting the maximum activity levels of both the passive diffusion and active transport absorption and the minimum level of renal reabsorption rate. According to the previous studies (Luo et al 2010;Tang et al 2012 meeting the metabolic requirements of juvenile yellow catfish. However, more investigation should be done to test this hypothesis, for example, using isotope-labeled techniques to measure the absorption rate of P in intestine.…”

“…Yellow catfish (Pelteobagrus fulvidraco), a freshwater species native to Asian-Pacific waters, is one of major commercial species and extensively cultured in aquaculture farms in China, The nutritional requirement for phosphorus content in their diet is important for their survival and growth during the juvenile stages (Luo et al 2010;Tang et al 2012). In this study, we use juvenile yellow catfish as an example to (1) investigate how dietary phosphorus level influences P wastes; (2) develop the AIC-selected empirical models for phosphorus metabolism; (3) discuss the potential mechanisms driving phosphorus metabolism in fish species.…”