4种豆粕替代鱼粉对大黄鱼生长、抗氧化及抗菌能力的影响

分别用9种等氮等能的饲料投喂初始体质量为(34.72±0.28)g的大黄鱼(Pseudosciaena crocea)。其中1组投喂对照饲料(含50%鱼粉,不含豆粕),另外8个试验组分别投饲由去皮豆粕(DSM)、酶解豆粕(ESM)、发酵豆粕Ⅰ(FSMⅠ)和发酵豆粕Ⅱ(FSMⅡ)替代20%和40%的鱼粉的饲料,9组分别命名为FM、DSM20、DSM40、ESM20、ESM40、FSMⅠ20、FSMⅠ40、FSMⅡ20、FSMⅡ40。在海水浮式网箱中进行7周的养殖实验后,评定4种豆粕替代鱼粉的可行性及适宜替代水平。结果显示,试验组与对照组鱼存活率和特定生长率无显著差异(P0.05)。血清生化指标显示,FM组和FSMⅡ20组超氧化物歧化酶(SOD)活性显著高于其它试验组(P0.05),FM、DSM20、FSMⅠ40、FSMⅡ20组过氧化氢酶(CAT)活性显著高于DSM40、ESM20、ESM40及FSMⅠ20组(P0.05),不同试验组的丙二醛(MDA)含量均不同程度高于对照组。酶解豆粕替代40%鱼粉导致实验鱼的血清对哈维氏弧菌的抵抗能力下降,去皮豆粕替代20%鱼粉导致血清对溶藻弧菌抵抗能力下降;但发酵豆粕不影响血清及黏液对3种菌的抵抗能力。研究表明,以特定生长率、饲料转化率和抗菌能力为评价指标,发酵豆粕是鱼粉的最佳替代源,发酵豆粕Ⅰ和Ⅱ均能替代20%~40%的鱼粉,但存在抗氧化能力下降的风险,尤其是发酵豆粕Ⅰ40%替代组;去皮豆粕和酶解豆粕替代鱼粉在抗菌能力和抗氧化能力方面无优势。

Effects of replacement of dietary fish meal by four kinds of soybean meal on growth,antioxidant and antibacterial ability of Pseudosciaena crocea R.

Due to the high protein content and rich essential amino acids for aquatic animals,fish meal has been widely used in aquaculture feed industry.However the worldwide fish meal supply can not meet the growing demand for aquaculture,it is necessary to look for alternative sources for fish meal.Soybean meal is easily digested and absorbed by aquatic animals,so it is one of the most widely used plant protein sources in aquatic feed .While excessive use of soybean meal with amino acid imbalance and many antinutritional factors in feed,affects not only feeding and growth of fish,but also the health and immune function.It has been demonstrated that the problem of antinutritional factors and amino acid imbalance can be eased by enzyme additives,microbial fermentation and crystalline amino acids additive.Large yellow croaker Pseudosciaena crocea R.is an important commercial marine fish species in China.It is favored by consumers due to its high nutritional value.As other carnivores,the high protein requirement of large yellow croaker is mainly from fish meal,so substitution of fish meal in the feed is also a key problem in their culture. In this study,a total of 1080 Pseudosciaena crocea R.with an average body weight of (34.72g ±0.28g) were randomly divided into 9 groups with 3 replicates each,and each replicate contained 40 fish.Fish were fed with 9 isonitrogenous and isoenergetic diets,the control group (50% fish meal,without soybean meal)and 8 experimental groups formulated by replacing 20% or 40% fish meal with dehulled,enzyme-treated, fermented soybean mealⅠor fermented soybean meal Ⅱwith crystalline amino acids,respectively.The 9 groups was respectively named as FM,DSM20,DSM40,ESM20,ESM40,FSMⅠ20,FSMⅠ40,FSMⅡ20,FSMⅡ40.A 7 -week trial was conducted in floating nets to evaluate the feasibility of the replacement of fish meal by four different kinds of soybean meal,and to measure the appropriate replacement level. Results showed that there was no significant difference in the survival rate,special growth rate between the control group and experimental groups.And there was no significant difference on feed conversion ratio, hepatosmatic index and condition factor among all groups.The superoxide dismutase activity and catalase in serum,liver and mucus were significantly different among groups.The superoxide dismutase activity of serum in FMand FSMⅡ20 was higher than other experimental groups.The catalase of serum in FM,DSM20,FSMⅠ40 and FSMⅡ20 was higher than that in DSM40,ESM20,ESM40 and FSMⅠ20.The malondialdehyde in serum and liver of replacement groups were higher than that in the control group.Serum showed significantly lower capacity to kill V.harveyi in the group of 40% fish meal replaced by enzyme-treated soybean meal and lower capacity to kill V.alginolyticus in the group of 20% fish meal replaced by dehulled soybean meal. Serum and mucus showed no significant difference on the capacity to kill A.hydrophila among all groups. Fermented soybean meal did not affect serum and mucus to kill the three kinds of bacteria .In conculsion, among the tested soybean meal,fermented soybean meal was the best substitution for fish meal,it could replace 20% -40% fish meal based on the specific growth rate,feed conversion ratio and antibacterial ability,but there was a risk of reduced antioxidation ability especially in the group of 40%fish meal replaced by fermented soybean meal I.While dehulled and enzyme-treated soybean meal had inferior position on antibacterial ability as well as antioxidation ability.