Growth, feed utilization and body composition of juvenile Manchurian trout, Brachymystax lenok (Pallas) fed different dietary protein and lipid levels. (4th September 2014)

• Record Type: Journal Article
• Authors: Xu, G.F.; Wang, Y.Y.; Han, Y.; Liu, Y.; Yang, Y.H.; Yu, S.L.; Mou, Z.B.
• Is Part Of: Aquaculture nutrition. Volume 21:Number 3(2015:Jun.)
• Page Start: 332
• Page End: 340
• Publication Date: 2014-09-04
• Subjects: body composition -- Brachymystax lenok (Pallas) -- growth -- lipid -- Manchurian trout -- protein; Aquaculture -- Periodicals; Aquatic animals -- Feeding and feeds -- Periodicals; Fishes -- Feeding and feeds -- Periodicals; 639.3
• DOI: 10.1111/anu.12165
• Languages: English
• ISSNs: 1353-5773

Abstract

Abstract: A 10‐week feeding trial with four dietary protein levels (400, 450, 500 and 550 g kg −1 crude protein) and two dietary lipid levels (80 and 160 g kg −1 crude lipid) was conducted to assess optimum dietary protein and lipid levels for the growth, feed utilization and body composition of juvenile Manchurian trout (initial weight 11.80 ± 0.15 g). Fish were fed twice daily (08:30 and 16:30 h) to apparent satiation. The results showed that fish fed the diet with 500 g kg −1 protein and 80 g kg −1 lipid had the highest growth and feed efficiency. However, fish fed the diet with 450 g kg −1 protein and 160 g kg −1 lipid showed comparable growth to that of the fish fed diet 5 (500/80) and had higher protein efficiency ratio (PER), nitrogen retention (NR) and energy retention (ER) than other groups ( P < 0.05). Growth, PER, NR and ER of fish fed the 160 g kg −1 lipid diet was significantly higher ( P < 0.05) than that of fish fed the 80 g kg −1 lipid diet at 400 and 450 g kg −1 protein diet, whereas these values showed an opposite trend at 500 and 550 g kg −1 protein diet, and the lowest PER, NR and ER was found by fish fed the 400 g kg −1 protein diet with 80 g kg −1 lipid. Fish fed diets with 400 g kg −1 protein had lower feed intake (FI) than that of other groups. Feed intake of fish fed 80 g kg −1 lipid level was significantly lower than that of fish fed 160 g kg −1 lipid diet at 400 g kg −1 protein ( P < 0.05), while no significant differences were observed at 450, 500 and 550 g kg −1 protein‐based diets. Contrary to moisture content, lipid content of whole body and muscle increased significantly ( P < 0.05) with increasing lipid levels. The results of this study indicated that the diet containing 450 g kg −1 protein and 160 g kg −1 lipid, with a P/E ratio of 23.68 g protein MJ −1 would be suitable for better growth and feed utilization of juvenile Manchurian trout under the experimental conditions and design level used in this study.