Feeding plant‐based diet through smoltification of Atlantic salmon requires verification of the optimal level of 1C nutrients. Here, we fed Atlantic salmon plant‐based diets containing three different surplus amounts of the 1C nutrients; methionine, cobalamin (vitamin B12), pyridoxine (vitamin B6) and folic acid during 6 weeks in fresh water, through smoltification, followed by 3 months on‐growing period in salt water. The three diets were fed to fish dispersed in triplicate tanks throughout the experiment. Mean start body weight was 32 g. Dietary methionine levels in the diets were 6.7, 9.2 and 11.7 g/kg. Dietary B6 was 6.75, 8.45 and 11 mg/kg. Cobalamin was 0.16, 0.18 and 0.20 mg/kg. While dietary folic acid was 2.9, 4.8 and 6.3 mg/kg, diets are referred to as low, medium and high 1C diet. All other amino acids were similar between diets. The results showed no differences in growth or feed utilization in the fresh water period, but following the on‐growing salt water period, differences between diets occurred. The fish fed the medium 1C diet showed better growth, as compared to fish fed the low or high 1C diet (p = .009). The medium 1C fed fish showed a relative lower liver weight compared with fish fed low or high 1C diet (p = .025). Condition factor was better in fish fed the medium and high 1C diet as compared to those fed the low 1C diet (p = .0006). As expected, free methionine in liver, plasma and muscle increased by dietary methionine inclusion. Surplus vitamins only had minor effect on tissue concentrations. Based on these findings, we conclude that the micronutrient and methionine level presented in the medium 1C diet improved the growth, liver size and condition factor; however, more research is needed to evaluate the optimal requirement level for each of the 1C nutrients.

中文翻译：

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大西洋鲑鱼喂食含有过剩蛋氨酸、维生素 B12、叶酸和维生素 B6 的营养包，可促进生长并减少肝脏的相对大小，但过度生长时会减少

通过大西洋鲑鱼的熏蒸喂养植物性饮食需要验证 1C 营养素的最佳水平。在这里，我们喂养大西洋鲑鱼植物性饮食，其中含有三种不同的 1C 营养素过剩量；甲硫氨酸、钴胺素（维生素 B12）、吡哆醇（维生素 B6）和叶酸在淡水中经过 6 周的熏蒸，然后在盐水中进行 3 个月的生长期。在整个实验过程中，将三种饲料喂给分散在三份鱼缸中的鱼。平均起始体重为 32 克。日粮中的日粮蛋氨酸水平为 6.7、9.2 和 11.7 g/kg。膳食 B6 为 6.75、8.45 和 11 mg/kg。钴胺素为0.16、0.18和0.20mg/kg。虽然膳食叶酸为 2.9、4.8 和 6.3 mg/kg，但膳食被称为低、中和高 1C 膳食。所有其他氨基酸在饮食之间相似。结果表明，淡水期的生长或饲料利用率没有差异，但在生长咸水期之后，日粮之间出现了差异。与喂食低或高 1C 饮食的鱼相比，喂食中等 1C 饮食的鱼表现出更好的生长 (p = .009)。与喂食低或高 1C 饮食的鱼相比，中度 1C 喂食的鱼的肝脏重量相对较低 (p = .025)。与喂食低 1C 饮食的鱼相比，喂食中高 1C 饮食的鱼的状况因子更好 (p = .0006)。正如预期的那样，肝脏、血浆和肌肉中的游离蛋氨酸因饮食中包含的蛋氨酸而增加。多余的维生素对组织浓度的影响很小。基于这些发现，我们得出结论，中等 1C 饮食中的微量营养素和蛋氨酸水平改善了生长、肝脏大小和状况因素；