饲料盐藻水平对卵形鲳鲹体色和生长的影响

摘要

A feeding trial was conducted to investigate the effects of dietary green alga Dunaliella salina levels on body pigmentation and growth of ovate pompano Trachinotus ovatus [initial mean body weight:(13.88±0.28) g].Six diets containing different D.salina levels (0.0%, 0.1%, 0.2%, 0.4%, 0.8%, and 1.6%) were formulated and fed to apparent satietion twice a day (8:00;17:00) to these groups of each 20 fish for 56 days.The results showed that the yellow value(b*) of dorsum and belly skin in ovate pompano was significantly in creased in the range of 0.1% to 1.6% of dietary D.salina levels (P<0.05).Addition of D.salina diet significantly improved the body color of ovate pompano.Meanwhile, the weight gain (WG) and specific growth rate (SGR) was found to be declined with the increasing dietary D.salina level(P>0.05).The fish in control group fed the diet containing no D.salina had the maximal protein efficiency ratio (PER) and the minimal feed conversion ratio (FCR), significantly different from group with 0.4% D.salina in its diet (P<0.05).It was found that add supplemetation of D.salina in diet did not lead to promoting effects in both growth and feed utilization of ovate pompano.There were no significant effects on body nutrient contents in the fish fed different D.salina level diets (P>0.05).%以初始体质量为(13.88±0.28) g的卵形鲳鲹为试验对象,研究不同盐藻添加量(0.0%、0.1%、0.2%、0.4%、0.8%、1.6%)饲料对其体色和生长的影响.每组设3个平行,每个平行饲养20尾鱼,每日饱食投喂2次(8:00;17:00),试验周期为56 d.结果显示,盐藻添加量为0.1%~1.6%时,随着饲料中盐藻水平的提高,卵形鲳鲹背部和腹部黄色值(b*)呈显著上升趋势(P<0.05),饲料中添加盐藻可明显改善卵形鲳鲹体色;与此同时,卵形鲳鲹质量增加率和特定生长率随饲料盐藻水平的上升呈下降趋势(P>0.05),未添加盐藻的对照组具有最高蛋白质效率和最低饲料系数,且与盐藻添加量为0.4%的试验组差异显著(P<0.05),饲料中添加盐藻对卵形鲳鲹生长性能和饲料利用没有明显的促进作用;此外饲料盐藻水平对卵形鲳鲹体成分也没有显著影响(P>0.05).