南极磷虾粉替代鱼粉对雌性黄鳝生长及生殖性能的影响

试验旨在研究南极磷虾粉替代鱼粉对雌性黄鳝(Monopterus albus)生长性能、体组成、抗氧化能力、非特异性免疫能力及生殖力的影响。选取二冬龄雌性黄鳝初始体重(36.41±3.62) g]900尾,随机分为6组(每组3个重复,每个重复50尾),分别饲喂以南极磷虾粉替代饲料中0(对照)、20%、40%、60%、80%和100%的鱼粉制成的6种等氮等能配合饲料,试验周期12周。结果表明:20%磷虾粉替代鱼粉时,雌性黄鳝的增重率(WGR)、特定生长率(SGR)与对照组无显著性差异(P>0.05),但随着替代水平的进一步提高其生长性能显著下降(P<0.05)。20%替代组黄鳝肌肉的粗蛋白质含量显著高于其他组(P<0.05),而粗脂肪、粗灰分各组间无显著差异(P>0.05)。对黄鳝卵巢营养成分进行分析表明,当磷虾粉替代鱼粉比例超过60%时,其粗蛋白、粗脂肪含量均显著下降,水分含量逐渐升高(P<0.05)。进一步对黄鳝肝脏的抗氧化能力进行分析显示,当磷虾粉替代鱼粉比例大于40%时,其超氧化物歧化酶(SOD)活性逐渐下降,而丙二醛(MDA)含量逐渐升高; 100...

ANTARCTIC KRILL MEAL REPLACEMENT OF FISH MEAL ON GROWTH PERFORMANCE AND FECUNDITY OF FEMALE MONOPTERUS ALBUS

Swamp eel (Monopterus albus) is one of the most important cultured fresh water species with high economic value in China, however, the present compound diets could not meet the growth and gonad development of swamp eel broodstocks, which hampered the large-scaled aquaculture of this species, therefore, the reproduction improvement of swamp eels by optimization of the compound diet formulation is on the urgent need. Antarctic krill meal is rich in sustainable resources and has the same nutritional level as fish meal, which meets the requirements of a new type of animal protein source for feed. Reports showed that Antarctic krill meal inclusion improved the growth and reproduction of several aquatic animals. In this study, two-winter-age female Monopterus albus with an initial body weight of (36.41±3.62) g was adopted. Antarctic krill meal was included to replace 0, 20%, 40%, 60%, 80%, and 100% fish meal to make 6 groups of iso-nitrogenous and iso-energetic diets. After 12 weeks of culture, the growth performance, body composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity of six groups of experimental eels were determined. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) of eels had no significant differences in 20% replacement group and the control group (P>0.05). However, the further increase of Antarctic krill meal substitution (>40%) led to the growth performance reduction. In muscle, crude protein concentration was higher in 20% substitution group than the other experimental groups; no significant differences were observed in the crude lipid and ash concentrations among different groups in muscle of swamp eels (P>0.05). In ovary, the nutrient composition had no significant difference between groups of 20% substitution group and the control group (P>0.05). Concentrations of crude protein and crude lipid decreased significantly while the moisture concentration increased gradually by Antarctic krill meal substitution from 60% to 100%. The further detection of the anti-oxidant capacity of liver revealed that superoxide dismutase (SOD) activity decreased gradually albeit with the increase of malondialdehyde (MDA) concentration in groups of Antarctic krill meal substitution higher than 40%. The catalase (CAT) activity in 100% substitution group was lower than the other five groups. The following non-specific immunity evaluation of liver suggested that no significant differences were observed between 20% substitution group and the control group in parameters of alkaline phosphatase (AKP), complement 4 (C4), and immunoglobulin M (IgM) (P>0.05). When the Antarctic krill meal substitution level were 60% or higher, the AKP activity showed the increased trend, while concentrations of C4 and IgM decreased instead. Lastly, fecundity of swamp eels in all groups were examined. The 20% Antarctic krill meal substitution did not influence fecundity parameters including gonadosomatic index (GSI), absolute fecundity, relative fecundity and serum estradiol concentration (P>0.05) in swamp eels. GSI in 80% and 100% groups were lower than that of 40% and 60% groups. From 60% to 100% substitution groups, the absolute fecundity, relative fecundity and estradiol concentrations decreased gradually with the increase of Antarctic krill meal inclusion. Egg diameters increased gradually with the increase of krill meal inclusions, but significant differences were only found from 100% group to groups of 0 and 20% (P<0.05). From the above results, it showed that the growth performance, ovarian nutrient composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity will not be influenced when 20% fish meal were replaced by Antarctic krill meal in diets of female swamp eels. Higher substitutions of Antarctic krill meal will intensify the adverse effect on this fish species. Therefore, the substitution of Antarctic krill meal of fish meal should not exceed 20% in formulated diets of female Monopterus albus.