:: Volume 17, Issue 4 (10-2018) ::
IJFS 2018, 17 Back to browse issues page
Effects of feeding levels on growth performance, feed utilization, body composition, energy and protein maintenance requirement of fingerling, rainbow trout, Oncorhynchus mykiss (Walbaum 1792)
A. Imtiaz *
, imtiazamu1@yahoo.com
Abstract:   (340 Views)
A 10-week feeding experiment was conducted to evaluate the effects of feeding level, energy and protein maintenance requirement of rainbow trout, Oncorhynchus mykiss, fingerling (5.65±0.45cm; 1.42±0.25g) by feeding casein-gelatin based purified diet (45% CP; 3.67 kcal g-1 GE) at six feeding levels from 2 to 7% of BW/day in two equal meals, at 0800 and 1700 h, in triplicate, with 20 fish per trough equipped with continuous water flow-through system water (60L volume). Maximum live weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR) and highest protein efficiency ratio (PER) were reported in fish fed 4-5% BW day-1. However, quadratic regression analysis for weight gain, FCR, PER, protein retention efficiency and energy retention efficiency data indicated the break-points occurred at 5.33, 4.50, 4.48, 4.63 and 4.74% BW day-1, respectively. Body composition also produced significant (p<0.05) differences with respect to each feeding level, maximum protein, lowest moisture and intermediate fat contents were reported at 4-5% feeding levels. Protein and energy retention values also produced significant (p<0.05) differences among each feeding level with maximum values were reported at 5% feeding level. Based on the results, it is recommended that feeding in the range of 4.6 to 5.3% BW day-1, corresponding to 2.07-2.39g protein and 16.88-19.45 kcal energy g100g-1 of the diet day-1 is optimum for the growth and efficient feed utilization of rainbow trout, while 2-3% feeding levels (0.90-1.35g protein and 7.34-11.01 kcal energy) suggests that these amounts approximate the maintenance requirement of fish.
Keywords: Oncorhynchus mykiss, Feeding rate, Growth performance, Maintenance requirement
Full-Text [PDF 425 kb]   (157 Downloads)    
Type of Study: Orginal research papers |
Received: 2018/09/25 | Accepted: 2018/09/25 | Published: 2018/09/25


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Volume 17, Issue 4 (10-2018) Back to browse issues page