Dietary Protein Requirement of Juvenile Dianchi Golden‐line Barbell, Sinocyclocheilus grahami

Abstract

A 10-wk feeding trial was conducted to estimate the dietary protein requirements of juvenile Dianchi golden-line barbell, Sinocyclocheilus grahami (initial average weight 7.55 g). Five isocaloric diets were formulated to contain graded levels of protein (29, 34, 39, 44, and 49%). Each diet was fed to triplicate groups of fish in a recirculating rearing system maintained at 18-22 C. Feed intake of fish fed the diet with 39% protein was significantly higher than those fed the diet with 29, 34, and 49% protein (P < 0.05). Weight gain, specific growth rate (SGR), and protein gain significantly increased with increasing dietary protein levels up to 39% (P < 0.05), whereas no significant differences were observed among fish fed the diet with 39, 44, and 49% protein (P > 0.05). In contrast, feed conversion ratio was significantly decreased with increasing dietary protein levels up to 39%. Maximum protein retention and protein efficiency ratio were observed in fish fed the diet with 39% protein. The regression analysis based on SGR and protein gain showed that the dietary protein requirements of juvenile S. grahami were 38.57% or 41.09% (equivalent to ca. 32.94% or 35.42% estimated digestible protein) of diet with a calculated digestible energy of 3.6 kcal/g.

Effects of Dietary Protein and Lipid Levels with Different Protein‐to‐Energy Ratios on Growth, Feed Utilization, and Plasma Biochemical Parameters of Dianchi Golden‐line Barbell, Sinocyclocheilus grahami

“…Thus, a diet containing 40% protein and 8% lipid with P/E ratio of 84.05 mg protein/kcal is optimal for S. grahami . This protein level is similar to the reported requirement for this species (38.6–41.1%; Deng et al ).…”

“…Little information on the nutritional requirements of this species has been reported. Our previous study showed that dietary protein requirement of juvenile S. grahami was between 38.6 and 41.1% of diet based on growth rate and protein gain (Deng et al ).…”

Digestible Protein Requirement of Pirarucu Juveniles (Arapaima gigas) Reared in Outdoor Aquaculture

“…However, in the current study, the protein content in the pirarucu youth fillet was not significantly affected by the dietary DP levels. These results concurred with those observed in the body protein content of other fish species (Abbas et al, 2011;Guo et al, 2012;Deng et al, 2014). Similarly, ash content, moisture, crude energy, and fillet lipids were not affected by changes in dietary protein levels.…”

Effects of dietary protein on growth performance, nutrient utilization, digestive enzymes and physiological status of grey mullet,Mugil cephalusL. fingerlings reared in inland saline water

“…Generally, the growth rate is positively related to the dietary protein levels in many species. However, growth of fish decreases or remains unaffected when fish are fed with dietary protein having lower or higher than optimum level (Kim & Lall, 2001;Shiau & Lan, 1996), because in such condition, protein synthesis is not favoured and a percentage of protein is catabolized resulting in reduction of protein conversion efficiency (Deng et al, 2014). Further, an insufficient supply of non-protein energy in feed also reduces growth performance despite having high protein in the diet due to preferential catabolism of protein (Winfree & Stickney, 1981).…”