Lane Ryan L, Trushenski Jesse T, Kohler Christopher C
Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University Carbondale, Carbondale, Illinois 62901-6511, USA.
Lipids. 2006 Nov;41(11):1029-38. doi: 10.1007/s11745-006-5053-2.
Marine oil-based finishing diets have been used to restore fillet FA profile in several "medium-fat" fleshed aquaculture species, and a simple dilution model describing FA turnover has been established to predict and tailor final fillet composition. We evaluated finishing diet efficacy and suitability of the dilution model to describe patterns of FA change in a lean-fleshed model, sunshine bass. Two practical diets (45% crude protein, 15% crude lipid) were formulated, respectively containing corn oil (CO) or menhaden oil (MO) as the primary lipid sources. Sunshine bass (age 1 [approximately 14 mo], 347 +/- 8.6 g, mean individual weight +/- SEM) were stocked in a recirculating system and fed the diets according to different feeding regimens during the final 28 wk of the production cycle. Control groups were fed the CO or the MO feeds exclusively; whereas, the remaining treatment groups were transitioned from the CO diet to the MO diet at 4-, 8-, or 12-wk intervals. Upon completion of the feeding trial, fish were harvested, and production performance and fillet composition were assessed. Replacing MO with CO as the primary lipid source in sunshine bass diets yielded fillets with distinctly different FA profiles; however, finishing with a MO-based diet offered significant compensation for CO-associated reductions in fillet long-chain highly unsaturated FA (LC-HUFA). Although complete restoration was not observed, we achieved significant augmentation of endogenous n-3 FA within 4 wk of feeding the MO diet, and observed a significant increase in LC-HUFA and a beneficial shift in n-3:n-6 FA ratio after 8 weeks. Simple dilution accurately predicted tissue composition for most FA; however, deviations from the model were noted, suggesting selective retention of n-3, PUFA, and LC-HUFA and preferential catabolism of saturates. We conclude marine oil-based finishing diets can rapidly augment beneficial FA levels in sunshine bass fillets; however, simple dilution models do not fully describe selective FA metabolism observed for this lean-fleshed fish.
海洋油基育肥饲料已被用于恢复几种“中等脂肪”肉质水产养殖品种的鱼片脂肪酸（FA）组成，并且已经建立了一个描述FA周转的简单稀释模型，以预测和调整最终鱼片的成分。我们评估了育肥饲料的功效以及稀释模型描述瘦肉质模型——阳光鲈中FA变化模式的适用性。配制了两种实用饲料（粗蛋白45%，粗脂肪15%），分别以玉米油（CO）或鲱鱼油（MO）作为主要脂质来源。将1龄（约14个月）、平均个体体重为347±8.6克（平均值±标准误）的阳光鲈放入循环系统中，并在生产周期的最后28周根据不同的投喂方案投喂这些饲料。对照组只投喂CO或MO饲料；而其余处理组则以4周、8周或12周的间隔从CO饲料过渡到MO饲料。投喂试验结束后，收获鱼并评估生产性能和鱼片成分。在阳光鲈饲料中用CO替代MO作为主要脂质来源会产生脂肪酸组成明显不同的鱼片；然而，以MO为基础的饲料育肥对与CO相关的鱼片长链高度不饱和脂肪酸（LC-HUFA）减少有显著补偿作用。虽然未观察到完全恢复，但在投喂MO饲料4周内我们实现了内源性n-3脂肪酸的显著增加，并且在8周后观察到LC-HUFA显著增加以及n-3:n-6脂肪酸比例发生有益变化。简单稀释能准确预测大多数脂肪酸的组织组成；然而，注意到与模型存在偏差，这表明n-3、多不饱和脂肪酸（PUFA）和LC-HUFA有选择性保留，而饱和脂肪酸有优先分解代谢。我们得出结论，海洋油基育肥饲料可以迅速提高阳光鲈鱼片中有益脂肪酸水平；然而，简单稀释模型不能完全描述这种瘦肉质鱼类中观察到的选择性脂肪酸代谢。
