Effects of L-carnitine enriched Artemia on medium and long chain fatty acids composition in first feeding larvae of grass carp, bighead carp and common carp, Ctenopharyngodon idella, Aristichysn obilis, Cyprinus carpio | L-肉碱强化卤虫对草鱼、鳙鱼和鲤鱼开口苗中长链脂肪酸组成的影响

صينى. 研究L-肉碱强化卤虫对草鱼、鳙鱼和鲤鱼开口苗中长链脂肪酸组成的影响。用0(对照，CK)，1，100，1 000 mg/L的L-肉碱分别强化卤虫无节幼体(Artemia sp.)12 h，投喂3种鱼开口苗21 d，测定鱼开口苗体内的脂肪酸含量，分析中长链脂肪酸(C14-C24)的组成。草鱼和鳙鱼开口苗的1和100 mg/L处理组的C18∶2n-6、C18∶3n-3、C20∶4n-6、DHA和EPA含量较对照组显著增加(P＜0.05)；3种鱼开口苗的1 mg/L处理组的C14-C24脂肪酸总含量、饱和脂肪酸和单不饱和脂肪酸含量较其他3组大多显著降低(P＜0.05)；草鱼和鳙鱼开口苗的100 mg/L处理组的多不饱和脂肪酸、n-3+n-6族脂肪酸以及DHA+EPA含量较对照组显著升高(P＜0.05)；L-肉碱强化的卤虫对鲤鱼开口苗多不饱和脂肪酸、n-3+n-6族脂肪酸及DHA+EPA含量没有显著影响(P＞0.05)。在本试验条件下，以100 mg/L L-肉碱强化卤虫无节幼体投喂鱼开口苗，可显著改善草鱼和鳙鱼开口苗的中长链脂肪酸组成，但对鲤鱼开口苗中长链脂肪酸组成的影响较小。

إنجليزي. Effects of L-carnitine enriched Artemia on medium and long chain fatty acids composition in first feeding larvae of three freshwater fish were studied. The experimental larvae were reared in a 50 L tank with stocking density of 40 fish/L at (25±1) ℃ for 21days.The newly hatched Artemia nauplii,enriched with 4 levels (0, 1, 100, 1000 mg/L) of L-carnitine at (25±1) ℃for 12 h, were used as starter food for rearing larvae. The medium and long chain fatty acids composition (C14-C24) in the experimental larvae were determined by GC and evaluated. Linoleic acid, linolenic acid, arachidonic acid, EPA and DHA content were significantly(P＜0.05) improved by feeding 1and 100 mg/L L-carnitine enriched nauplii than the control group in the first feeding larvae of grass carp and bighead carp; ∑C14-C24 FA, SFA and MUFA content of larvae were decreased significantly(P＜0.05) by feeding 1 mg/L L-carnitine enriched nauplii than the other groups in the three species freshwater fish; there was significantly(P＜0.05) higher PUFA, ∑n-3+∑n-6 and DHA+EPA content for grass carp and bighead carp in 100 mg/L L-carnitine enriching groups than in the control; no significant difference(P＞0.05) was observed in PUFA, ∑n-3+∑n-6 and DHA+EPA content in the first feeding larvae of common carp. Therefore, the 100 mg/L L-carnitine enriched nauplii could remarkably enhance medium and long chain fatty acids composition of the first feeding larvae of grass carp and bighead carp, but there was less effect on medium and long chain fatty acids composition of common carp.