Understanding fatty acid requirements in multiple taxa is necessary to determine the degree to which dietary fish oil can be reduced or replaced with less costly, more abundant lipid sources. The polyunsaturated fatty acid (PUFA) requirements of hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis) are currently reported as 0.5–1.0% eicosapentaenoic acid (20:5n‐3) and/or docosahexaenoic acid (22:6n‐3). This requirement does not account for n‐3 PUFA essentiality on an individual fatty acid basis and does not address possible requirements for n‐6 PUFAs (i.e., linoleic acid [18:2n‐6] or arachidonic acid [20:4n‐6]). Accordingly, hybrid Striped Bass were fed diets containing selected individual n‐3 and n‐6 C₁₈ PUFAs, n‐3 and n‐6 long‐chain (LC) PUFAs, or combinations thereof to determine the essentiality or expendability of these nutrients. These experimental feeds were compared to feeds containing only saturated fatty acids (negative control) or menhaden fish oil (positive control). Growth performance and ratios of 22:5n‐6 : 22:6n‐3 observed in tissue fatty acid profiles suggested that dietary provision of 22:6n‐3 was adequate to satisfy physiological demand for LC‐PUFAs. However, reductions in feed conversion ratio and numeric improvements in growth suggest that dietary provision of 20:4n‐6 is also important. Results of this study indicate that provision of C₁₈ PUFAs alone is insufficient to avoid essential fatty acid deficiency and to support optimal growth of this fish. To ensure that essential fatty acid requirements are met and performance is optimized, diets for hybrid Striped Bass should be formulated to contain 22:6n‐3 and 20:4n‐6, if not a full complement of n‐3 and n‐6 LC‐PUFAs.

中文翻译：

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重新评估混合条纹低音中的多不饱和脂肪酸的必要性

必须了解多种生物分类中的脂肪酸需求，才能确定可以减少或以更便宜，更丰富的脂质来源代替鱼油的程度。杂种条纹鲈鱼（白鲈Morone chrysops  ×条纹鲈M. saxatilis）的多不饱和脂肪酸（PUFA）要求目前报告为0.5–1.0％二十碳五烯酸（20：5n-3）和/或二十二碳六烯酸（22：6n） ‐3）。此要求未考虑单个脂肪酸对n-3 PUFA的要求，也未解决对n-6 PUFA（即亚油酸[18：2n-6]或花生四烯酸[20：4n-6]）的可能要求。 ）。因此，混合条纹鲈鱼饲喂含有选定的单个n-3和n-6 C _18的日粮PUFA，n-3和n-6长链（LC）PUFA或其组合，以确定这些营养素的必要性或可消耗性。将这些实验性饲料与仅含饱和脂肪酸（阴性对照）或鲱鱼油（阳性对照）的饲料进行了比较。在组织脂肪酸谱中观察到的生长性能和22：5n-6：22：6n-3的比例表明，饮食中22：6n-3的摄入量足以满足LC-PUFA的生理需求。但是，饲料转化率的降低和生长量的数字提高表明，饮食中20：4n-6的摄入量也很重要。这项研究的结果表明，提供C ₁₈仅PUFA不足以避免必需脂肪酸缺乏和支持该鱼的最佳生长。为确保满足必需脂肪酸要求并优化性能，混合条纹鲈鱼的日粮应配制为22：6n-3和20：4n-6，如果不能完全补充n-3和n-6 LC ‐PUFA。