饲料中不同水平维生素A对半滑舌鳎亲鱼繁殖性能及后代质量的影响

Effects of dietary vitamin A supplementation on the reproduction and offspring quality of tongue sole Cynoglossus semilaevis

中文关键词: 半滑舌鳎  亲鱼  维生素A  繁殖性能  卵子质量

英文关键词: Cynoglossus semilaevis  Broodstock  Vitamin A  Reproductive performance  Egg quality

中文摘要:

      在饲料中分别添加0、20、100 IU/g的维生素A（视黄醇乙酸酯形式）配制成Ac、Al和Ah 3种试验饲料饲喂3龄半滑舌鳎亲鱼[雌性(1.58±0.18) kg/尾、雄性(0.20±0.05) kg/尾]70 d，探讨饲料中不同水平的VA对半滑舌鳎亲鱼繁殖性能的影响。结果显示，Al组和Ah组雌鱼性腺成熟率均要高于Ac组；相对产卵量Al组最高，Ac组最低；Al和Ah组的受精率和孵化率均显著高于Ac组（P<0.05）；Al组的卵上浮率、初孵仔鱼长度、仔鱼的成活率和仔鱼生存活力指数（SAI）均显著高于Ac组和Ah组（P<0.05）；随饲料中VA的增加仔鱼畸形率虽有增加趋势，但无显著性差异（P>0.05）；而卵巢、肝脏和卵子中VA的含量和血清中SOD的活性均随饲料中VA的增加而显著提高（P<0.05）。此外，Al组和Ah组卵子中维生素C的含量以及卵子脂肪酸中n-3HUFA、n-6PUFA和PUFA的含量均要高于Ac组。综上所述，饲料中添加适量VA可促进半滑舌鳎亲鱼性腺的发育，提高产卵量，改进卵子和仔鱼的质量；本研究中Al组（20 IU/g）亲鱼的繁殖性能要优于Ac组（0 IU/g）和Ah组（100 IU/g）。

英文摘要:

      This study evaluated the effects of vitamin A supplementation on the reproduction and offspring quality of tongue sole Cynoglossus semilaevis. Broodstock (females, average weight 1.58 kg; males, average weight 0.2 kg) were fed with one of the three diets (Ac, control, no vitamin A supplementation; Al, 20 IU/g vitamin A as retinol acetate; and Ah, 100 IU/g vitamin A as retinol acetate) for 10 weeks at water temperature of 19-25℃. Results showed that female gonad mature rates (GMA) in the Al and Ah groups were higher than that of the Ac group. The relative fecundity in the Al group was the highest (1.57×10⁵ ind./kg), while that in the Ac group was the lowest (1.00×10⁵ ind./kg). Hatching and fertilization rate in the Al and Ah groups were significantly higher than those in the Ac group (P<0.05). Buoyant eggs rate, larvae length, larvae survival rate and survival activity index of larvae (SAI) were the highest in the Al group. The dietary vitamin A supplementation increased the abnormal larvae ratio, but the effect was not significant (P>0.05). Vitamin A content in the tissues and eggs and activity of the superoxide dismutase (SOD) in serum were significantly increased with the increasing dietary vitamin A level (P<0.05). In addition, compared to those in the control group, vitamin C levels in the eggs were significantly higher in the two treatment groups (P<0.05); and the oxidation resistance of the eggs increased in the two treatment groups. The levels of n-3HUFA, n-6PUFA and PUFA in the eggs in the Al and Ah groups were all higher than those in the Ac group. These results demonstrated that the proper amount of vitamin A supplemented in the diet may promote the development of broodstock gonads and improve the quality of the eggs and larvae. The broodstock in the Al group (20 IU/g) had the best reproductive performance compared to those in the Ac and Ah groups．