Nutritive value of partially dehulled and extruded sunflower meal for post-smolt Atlantic salmon (Salmo salar L.) in sea water |
| |
Authors: | Navneet Gill David A Higgs Brent J Skura Mahmoud Rowshandeli Bakhshish S Dosanjh Jason Mann & Ann L Gannam |
| |
Institution: | Faculty of Land and Food Systems, Food, Nutrition and Health, The University of British Columbia, Vancouver, BC, Canada V6 T 1Z4; Department of Fisheries and Oceans, University of British Columbia, Centre for Aquaculture and Environmental Research, West Vancouver, BC, Canada V7V 1N6; Ewos Canada Ltd, Surrey, BC, Canada V3W 4M8; US Fish and Wildlife Service, Abernathy Fish Technology Center, Longview, WA, USA |
| |
Abstract: | This study determined the digestibility of protein in partially dehulled sunflower meal (SFM) and then, as the main goal, the nutritive value of high‐temperature extruded (≤149°C) partially dehulled SFM (SFMEX) for post‐smolt Atlantic salmon Salmo salar in sea water. The digestibility study was conducted using the settling column approach (‘Guelph system’) for faeces collection as described by Hajen, Higgs, Beames and Dosanjh. In the nutritive value study, triplicate groups of 50 salmon (mean weight ~116 g) in 4000‐L outdoor fibreglass tanks supplied with 25–40 L min?1, filtered, oxygenated (dissolved oxygen, 7.0–8.5 mg L?1), 11–12°C sea water (salinity, 29–31 g L?1), were fed twice daily to satiation one of five steam‐pelleted dry diets that contained 422 g of digestible protein (DP) kg?1 and ~16.4 MJ of digestible energy (DE) kg?1 on a dry weight basis for 84 days. Low‐temperature‐dried anchovy meal (LT‐AM) comprised 68.2% of the basal diet protein whereas in four test diets, SFMEX progressively replaced up to 33.0% of the DP provided by LT‐AM in the basal diet (SFMEX≤271 g kg?1 of dry matter). Sunflower meal had 87.9% DP. Diet treatment did not significantly affect specific growth rate (1.39–1.45% day?1), feed efficiency (1.19–1.26), percentage of dietary protein retained (45.8–47.5), gross energy utilization (46.5–49.4%), per cent survival (96.0–99.3) or terminal whole body and muscle proximate compositions. We conclude that SFMEX can comprise ≥271 g kg?1 of the dry diet or ≥22.7% of the digestible dietary protein of post‐smolt Atlantic salmon in seawater without any adverse effects on their performance. |
| |
Keywords: | Atlantic salmon Salmo salar sunflower meal growth |
|
|