Popis: |
Atlantic salmon, Salmo salar L., fingerlings with a mean weight of 1.5 g were fed one of four casein-gelatine-based purified diets supplemented with soya lecithin (LC) and choline chloride (CH) for 84 days. The diets were supplemented with either: 0 g kg−1 CH and 0 g kg−1 LC, 0 g kg−1 CH and 30 g kg−1 LC, or 5 g kg−1 CH and 0 g kg−1 LC, or 5 g kg−1 CH and 30 g kg−1 LC. The same diets were also fed to 100-g salmon to assess the effects of LC and CH supplementation on digestibility. Fingerlings fed the diet with neither LC nor CH (0 g kg−1 LC and 0 g kg−1 CH) grew at a significantly slower rate than fish fed the supplemented diets. There were significant effects on growth of supplementation of both LC and CH. The results indicate that the choline requirement of Atlantic salmon fingerlings is satisfied by 4 g kg−1 inclusion in a gelatine-casein-based diet, and that dietary soya lecithin can fully replace choline chloride. The digestibility study with the larger fish indicated a beneficial effect of lecithin on the digestibility of both protein and energy. |