不同蛋白水平的虾青素饲料对锦鲤体色、生长及免疫的影响

Effects of dietary protein levels on body pigmentation,growth and immunology of ornamental carp(Cyprinus carpioL.)

以初始体重为(5.85±0.19)g的红白锦鲤幼鱼为实验对象,研究虾青素有效添加量为130 mg/kg时,饲料蛋白水平(25.49%、30.84%、35.04%、40.68%、45.88%)对锦鲤体色、生长及免疫的影响。每组设3个平行,每个平行饲养20尾鱼,表观饱食投喂60 d后,实验结果显示:饲料蛋白水平为35.04%时,实验鱼体表红质a*值最高,与蛋白水平40.68%组间无显著差异(P>0.05),但显著高于其他实验组(P<0.05),与此同时,皮肤中类胡萝卜素含量显著升高(P<0.05),最大值出现在蛋白水平45.88%组。蛋白水平为35.04%时,实验鱼的增重率(RWG)、特殊生长率(RSG)以及蛋白质效率(RPE)最高。蛋白水平对实验鱼溶菌酶(LZM)以及实验鱼肝胰脏(CAT)、乳酸脱氢酶(LDH)无显著影响(P>0.05),蛋白水平为45.88%时,SOD活力显著降低(P<0.05)。上述研究说明,虾青素添加量为130 mg/kg时,使锦鲤生长、着色达到最好效果的适宜饲料蛋白水平为35.04%。同时本研究的结果表明,在配合饲料中,提高饲料蛋白水平不会持续提高锦鲤对虾青素的利用效率。

A feeding trial was conducted to investigate the effects of dietary protein levels on body pigmentation, growth and immunology of ornamental carp （Cyprinus carpio L. ） （initial mean body weight： 5.85 ±0.19 g）. The diet contained 130 mg/kg astaxanthins： Fish were fed with different protein levels （25.49% ,30.84% ,35.04% ,40.68% ,45.88% ） and fed to apparent satiety to these groups of 20 fish for 60 days. The results showed that： The value of a ＊ was highest in the protein level of 35.04% , no significant differences compared with protein level 40.68 % （ P 〈 0.05 ） , but obviously higher than other experimental groups （P 〉 0.05 ）. The concentration of carotenoid in the skin of fish had significant differences from other experimental groups （P 〈 0.05 ）at the same level while the highest value in the group protein level 45.88%. The highest body weight gain and feed conversion ratio occurred in the protein level 35.04%. There were no significant effects on LZM, CAT and LDH （ P 〉 0.05 ）. While the activity of SOD decreased obviously at the protein level of 45. 88% （ P 〈 0. 05 ）. The results of this study also illustrated that the utilization of astaxanthin of ornamental carp（ Cyprinus carpio L）did not improve constantly with the increase of protein level in diet.