天然叶黄素对黄颡鱼生长性能和皮肤着色的影响

研究了天然叶黄素(源自万寿菊,含量为4.64％)的添加水平对黄颡鱼生长和皮肤着色效果的影响.在黄颡鱼基础饲料中,分别添加0％、0.15％、0.30％、0.60％、8.00％的受试物,在不影响饲料营养水平的基础上设计最高剂量组为可能摄入剂量组的10倍以上,经挤压熟化工艺加工后,实际检测叶黄素含量为未检出(检出限=0.5 mg/kg)、24.2、54.2、118.0、1 700.0mg/kg,依次命名为C、L24.2、L54.2、L118、L1700.饲养90 d后发现,添加天然叶黄素的4个剂量组的特定生长率和饲料效率、L24.2组的蛋白沉积率、L54.2组和L118组及L1700组的能量沉积率均显著高于对照组(P＜0.05).体侧和腹部皮肤的黄度(b*)和饱和度(C*)随饲料中天然叶黄素含量的增加而逐步升高,L118组可达到饱和,并与L1700组之间没有显著差异(P＞0.05),L118组和最高剂量组皮肤中黄色素过度沉积,并向肌肉中转移.皮肤中叶黄素的蓄积系数呈现先升高后下降的趋势,最高为76.25 mg/kg饲料.结果表明,24.2～1700mg/kg的天然叶黄素显著提高了初始体质量21 9的黄颡鱼的生长性能.天然叶黄素作为黄颡鱼皮肤着色剂的最适剂量为76.25 mg/kg饲料.

Effect of natural xanthophylls on growth performance and body pigmentation of yellow catfish(Pelteobagrus fulvidraco)

A 90 d experiment was conducted to investigate the effects of dietary natural lutein levels on growth, and body pigmentation of Pelteobagrus fulvidraco. Five experimental diets were designed with 0%, 0.15%, 0.3%, 0.6% and 8% of test compound and the highest dose was ten times more than possible dose. Five extruded pellets were determined xanthophylls dosage as non detected, 24.2, 54.2, 118 and 1700 mg/kg, respectively, which were named C, L24.2, L54.2, L118 and L1700 accordingly. Each treatment was randomly assigned four replicates with 30 fish in each tank. We found pigment inclusion did significantly enhance growth performance and feed efficiency of P. fulvidraco. Productive protein value of L24.2 group, energy productive values of L54.2, L118, L1700 groups were significantly higher than those of control group (P<0.05). Yellowness (b^*) and saturation (c^*) of lateral and ventral skin obviously increased until they reached saturation in L118, which showed no difference with L1700 group(P>0.05). Pigmentation of skin in L118 and L1700 deposited excessively and transferred into muscle. Bioaccumulation factor of skin pigment increased firstly and then decreased, the highest in fish fed 76.25 mg/kg diet. The results showed 24.2-1700 mg/kg pigment inclusion significantly improved growth performance of P. fulvidraco. The optimum concentration of pigment as a colorant in yellow catfish was 76.25 mg/kg feed.