The need for new alternative oil sources in the ever-increasing aquaculture of carnivorous species is imperative. We substituted fish oil (FO) with hazelnut oil (HO) in meagre diet at 20, 40, 60, 80 and 100%. Triplicate groups of 40 fish/tank juvenile meagre (ca 15 g) were used. For the reduction of FO level in meagre diet, a 40% substitution by HO is attainable without affecting growth performance. However, higher substitutions appear to have a negative effect on growth performance and feed efficiency, although daily feed intake seems to remain unaffected by the reduction in FO. No effects on whole-body protein and lipid concentration were observed for fish fed the experimental diets. Whole-body fatty acid composition reflected the dietary fatty acid composition in all dietary groups. Diets with higher than 40% levels of FO substitution significantly reduce highly unsaturated ω-3 fatty acids in the fish. Although the metabolic relationship between carbohydrate and fatty acid exploitation is extremely versatile, and thus it is difficult to reach a safe conclusion, it seems that FO substitution by HO activates fish carbohydrate, rather than fatty acids, exploitation machinery. These results support the use of HO in meagre diets up to 40% FO substitution with a future thought for more efficient use of 30% FO substitution by HO.

中文翻译：

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榛子油替代鱼油对幼鱼生长性能、全身脂肪酸组成和中间代谢酶的影响 (Argyrosomus regius Asso, 1801)

在不断增长的肉食性物种水产养殖中，对新的替代油源的需求势在必行。我们以 20%、40%、60%、80% 和 100% 的比例在微薄的饮食中用榛子油 (H2O) 代替鱼油 (FO)。使用 40 条鱼/鱼缸幼鱼（约 15 克）的三份重复组。为了降低微薄饮食中的 FO 水平，可以在不影响生长性能的情况下实现 40% 的 H2O 替代。然而，更高的替代品似乎对生长性能和饲料效率有负面影响，尽管每日采食量似乎不受 FO 减少的影响。对于喂食实验饮食的鱼，没有观察到对全身蛋白质和脂质浓度的影响。全身脂肪酸组成反映了所有膳食组的膳食脂肪酸组成。FO 替代水平高于 40% 的饮食会显着降低鱼中的高度不饱和 ω-3 脂肪酸。尽管碳水化合物和脂肪酸开发之间的代谢关系非常多变，因此很难得出一个安全的结论，但似乎 FO 被 H2O 替代激活了鱼类碳水化合物，而不是脂肪酸，开发机制。这些结果支持在低至 40% FO 替代的微薄饮食中使用 H2O，未来会更有效地使用 H2O 替代 30% FO。而不是脂肪酸，剥削机器。这些结果支持在低至 40% FO 替代的微薄饮食中使用 H2O，未来会更有效地使用 H2O 替代 30% FO。而不是脂肪酸，剥削机器。这些结果支持在低至 40% FO 替代的微薄饮食中使用 H2O，未来会更有效地使用 H2O 替代 30% FO。