动物营养学报  2015, Vol. 27 Issue (7): 2115-2127   PDF (1207KB)    
大豆抗原蛋白对南美白对虾生长、消化及非特异性免疫的影响
陈晓明1,2, 华雪铭1,2 , 朱伟星1,2, 何亚丁1,2, 税春3, 吴钊1,2, 陈青青1,2, 孔纯1,2    
1. 上海海洋大学农业部淡水水产种质资源重点实验室, 上海 201306;
2. 上海市水产养殖工程技术研究中心, 上海 201306;
3. 上海市水产研究所, 上海 200433
摘要:本试验旨在研究发酵豆粕替代饲料中鱼粉及豆粕时,大豆球蛋白和β-伴球蛋白对南美白对虾生长、消化及非特异性免疫的影响。试验1:首先配制含30%鱼粉和15%豆粕的基础饲料(D0组),然后分别用2%(D2组)、5%(D5组)、8%(D8组)和15%(D15组)的发酵豆粕替代基础饲料中的鱼粉和豆粕,共配制出5种等氮等能的试验饲料。试验2:首先配制基础饲料(即试验1中的基础饲料),然后分别用酪蛋白(DC组,不含抗原蛋白)和大豆分离蛋白(DF组,含少量抗原蛋白)完全替代基础饲料中的豆粕,共配制出3种等氮等能的试验饲料。选用初始均重为(5.86±0.04) g的南美白对虾进行试验,随机分为7组,每组3个重复(60尾/重复),在室外水泥池中养殖44 d。试验1结果显示:随着发酵豆粕添加量的增加,饲料系数呈先降后升趋势,以D5组最低;蛋白质效率和成活率呈先升后降趋势,分别以D5、D8组最高。全虾粗蛋白质和粗脂肪含量、肝胰指数均以D8组最高,均显著高于D5组(P < 0.05)。D15组的干物质表观消化率显著低于D0组(P<0.05);D5组粗蛋白质表观消化率显著低于其余各组(P<0.05)。肝胰腺淀粉酶、脂肪酶和胰蛋白酶活力随发酵豆粕添加量的增加均呈先升后降的趋势,分别在D8、D5和D2组获得最大值。肝胰腺超氧化物歧化酶、溶菌酶和碱性磷酸酶活力随发酵豆粕添加量的增加基本呈降低趋势;D5、D8、D15组的肝胰腺谷草转氨酶活力显著低于D0组(P < 0.05);肝胰腺谷丙转氨酶活力表现为D2组显著低于其他各组(P < 0.05)。试验2结果显示:成活率、蛋白质效率和饲料系数各组间均存在显著差异(P < 0.05),且均以DF组最高。DC和DF组的全虾粗蛋白质含量显著高于D0组(P < 0.05);DF组的全虾粗脂肪含量显著低于DC和D0组(P < 0.05);DC组的肝胰指数显著高于DF和D0组(P < 0.05)。干物质和粗蛋白质表观消化率均以DF组最低,并显著低于D0和DC组(P < 0.05)。肝胰腺淀粉酶和脂肪酶活力表现为DC组>DF组>D0组,组间差异显著(P < 0.05);DC组的肝胰腺胰蛋白酶活力显著低于D0组(P < 0.05)。DC组的肝胰腺超氧化物歧化酶活力显著低于DF组(P < 0.05),溶菌酶活力显著低于D0组(P < 0.05),而碱性磷酸酶、谷草转氨酶和谷丙转氨酶活力则显著高于D0和DF组(P < 0.05)。以上结果表明大豆抗原蛋白(球蛋白和β-伴球蛋白)影响南美白对虾的生长、 消化和非特异性免疫;大豆抗原蛋白含量的降低有助于南美白对虾饲料中发酵豆粕对鱼粉和豆粕的替代。在本试验条件下,南美白对虾饲料中使用不超过15%的发酵豆粕替代鱼粉和豆粕是可行的。
关键词替代     南美白对虾     秘鲁鱼粉     发酵豆粕     生长     肝胰腺指标    
Effects of Soybean Allergic Proteins on Growth, Digestion and Non-Specific Immune of Litopenaeus vannamei
CHEN Xiaoming1,2, HUA Xueming1,2 , ZHU Weixing1,2, HE Yading1,2, SHUI Chun3, WU Zhao1,2, CHEN Qingqing1,2, KONG Chun1,2    
1. Key Laboratory of Freshwater Fishery Germplasm Resources of Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China;
2. Shanghai Engineering Research Centre of Aquaculture, Shanghai 201306, China;
3. Shanghai Fisheries Research Institute, Shanghai 200433, China
Abstract: This experiment was conducted to investigate the effects of soybean glycinin and β-conglycinin on growth, digestion and non-specific immune of Litopenaeus vannamei when the dietary fish meal (FM) and soybean meal (SBM) substitution with fermented soybean meal (FSBM). In experiment 1, five isonitrogenous and isoenergetic diets were formulated for L. vannamei, a basal diet (D0 group) contained 30% FM and 15% SBM was formulated firstly, and then the FM and SBM (2:1) in the basal diets were replaced by 2% (D2 group), 5% (D5 group), 8% (D8 group) and 15% (D15 group) of FSBM, respectively. In experiment 2, three isonitrogenous and isoenergetic diets were formulated for L. vannamei, a basal diet (the same as D0 group in experiment 1) was formulated firstly, and then replacing SBM in the basal diet with casein (no allergic proteins, DC group) and soybean protein isolate (contained a little allergic proteins, DF group) completely to meet the lower soybean allergic proteins in diets. L. vannamei with the initial average body weight of (5.86±0.04) g were randomly assigned to 7 groups with 3 replicates of 60 shrimp for each group in outdoor cement tank cultured 44 days. Results of experiment 1 showed that with FSBM supplemental level increasing, the feed conversion ratio (FCR) was firstly decreased and then increased and the lowest value was found in D5 group; protein efficiency ratio (PER) and survival rate (SR) were firstly increased and then decreased and the highest values were found in D5 and D8 groups, respectively. The whole body crude protein and crude lipid contents, and hepatosomatic index in D8 group were the highest, and significantly higher than those in D5 group (P < 0.05). The apparent digestibility of dry matter (ADDM) in D15 group was significantly lower than that in D0 group (P < 0.05); the apparent digestibility of crude protein (ADCP) in D5 group was significantly lower than that in other groups (P < 0.05). The activities of amylase, lipase and trypsin in hepatopancreas were firstly increased and then decreased, and the highest values were found in D8, D5 and D2 groups, respectively. The activities of superoxide dismutase (SOD), lysozyme (LYZ) and alkaline phosphatase (AKP) in hepatopancreas were observed a tendency of decrease with FSBM supplemental level increasing. Hepatopancreas aspartate aminotransferase (AST) activity in D5, D8 and D15 groups was significantly lower than that in D0 group ( P < 0.05), while hepatopancreas alanine aminotransferase (ALT) activity in D2 group was significantly lower than that in other groups (P < 0.05). Results of experiment 2 showed that SR, PER and FCR were significant differences in all groups (P < 0.05), and highest values were found in DF group. The whole body crude protein content in DC and DF groups was significantly higher than that in D0 group (P < 0.05); the whole body crude lipid content in DF group was significantly lower than that in DC and D0 groups (P < 0.05); the hepatosomatic index in DC group was significantly higher than that in DF and D0 groups (P < 0.05). ADDM and ADCP had the lowest values in DF group, which were significantly lower than those in D0 and DC groups (P < 0.05). The activities of amylase and lipase in hepatopancreas were showed that DC group>DF group>D0 group, and significant differences were found among all groups (P < 0.05); the activity of trypsin in hepatopancreas DC group was significantly lower than that in D0 group (P < 0.05). The hepatopancreas SOD activity in DC group was significantly lower than that in DF group (P < 0.05), and the hepatopancreas LYZ activity in DC group was significantly lower than that in D0 group (P < 0.05), while the activities of hepatopancreas AKP, AST and ALT in DC group were significantly higher than those in D0 and DF groups (P < 0.05). In conclusion, soybean allergic proteins (glycinin and β-coglycinin) affect growth, digestion and non-specific immune of L. vannamei. Decreasing of allergic proteins content in diets has beneficial effects for FM and SBM in diets are replaced by FSBM. In present experiment, suggesting that FM and SBM are replaced by no more than 15% of FSBM is feasible in the formulation of L. vannamei diet.
Key words: replacement     Litopenaeus vannamei     Peru fish meal     fermented soybean meal     growth     hepatopancreas parameters    

鱼粉含有丰富的营养成分,是对虾饲料中重要的蛋白质源,在对虾商品饲料中的用量通常为25%~50%[1, 2, 3]。由于鱼粉供应受限,价格不断上涨,水产养殖业亟待寻找一种或多种蛋白质源替代鱼粉[4]。豆粕作为全球产量最高的植物蛋白质源,富含多种氨基酸,且可消化氨基酸比其他植物蛋白质源更符合多数动物的营养需求[5];此外,其价格相对低廉、产品稳定性好。因此,很多学者用豆粕作为斑节对虾(Penaeus monodon)、南美白对虾(Litopenaeus vannamei)和克氏原螯虾(Procambarus clarkii)饲料中鱼粉的替代源[6, 7, 8, 9, 10, 11, 12, 13]

然而,豆粕中含有包括球蛋白和β-伴球蛋白在内的抗原蛋白等多种抗营养因子,限制水产动物对营养物质的吸收利用[14]。其中,球蛋白易造成易过敏仔猪局部系统免疫反应的应激并抑制其生长[15];β-伴球蛋白在引起哺乳动物肠道损伤的同时[16],还会抑制生长、降低体液免疫功能等[17]。大豆抗原蛋白对草鱼(Ctenopharyngondon idellus)、鲤(Cyprinus carpio)和埃及胡子鲇(Clarias leather)肌肉营养成分、生长和饲料利用率也有负面的影响[18, 19, 20, 21]。因此,钝化或消除抗营养因子对营养物质利用的负面影响成为提高豆粕利用率的关键。研究发现,对豆粕进行发酵可以降低豆粕中球蛋白和β-伴球蛋白等的含量[22, 23, 24],促进断奶仔猪、奶牛和虹鳟(Oncorhynchus mykiss)的生长,显著提高对饲料的消化率[25, 26, 27, 28]

南美白对虾分布于东太平洋,北起墨西哥的索诺拉州,南至秘鲁,是世界最主要的养殖虾类之一,其产量占养殖虾类总量的70%以上[29],我国养殖南美白对虾的产量领跑世界[30]。鉴于豆粕中的抗营养因子对动物的负面影响,已有学者先后使用发酵豆粕作为南美白对虾饲料中鱼粉的替代源[31, 32, 33],但究竟哪些抗营养因子对对虾类造成影响还没有明确的报道[34]。本研究以南美白对虾为试验对象,利用大豆抗原蛋白(球蛋白和β-伴球蛋白)明显减少的发酵豆粕替代饲料中的鱼粉和豆粕(2 ∶ 1),研究发酵豆粕替代对鱼粉和豆粕的替代效果,探讨大豆抗原蛋白对南美白虾生长、消化及非特异性免疫的影响,旨在为合理利用发酵豆粕及探究大豆抗原蛋白在虾体中的作用机制提供理论依据。

1 材料与方法 1.1 试验设计

试验1:为了探讨发酵豆粕对鱼粉和豆粕的替代效果,首先以秘鲁鱼粉、肉骨粉、花生粕、豆粕和发酵豆粕等为主要蛋白质源,鱼油和磷脂为主要脂肪源,配制基础饲料。然后分别用0、2%、5%、8%和15%的发酵豆粕对基础饲料中鱼粉和豆粕进行(2 ∶ 1)替代,并对其他原料的添加量进行微调,配制成5种等氮等能饲料(表1),分别命名为D0、D2、D5、D8和D15。本试验所用豆粕中球蛋白含量约为180 mg/g,β-伴球蛋白含量约为140 mg/g,发酵豆粕中球蛋白含量约为10 mg/g,β-伴球蛋白含量约为3 mg/g。试验2:为了探讨发酵豆粕对鱼粉和豆粕的替代效果与大豆抗原蛋白(球蛋白和β-伴球蛋白)的可能关系,以秘鲁鱼粉、肉骨粉和豆粕等为主要蛋白质源配制基础饲料,即试验1中的D0;以秘鲁鱼粉、肉骨粉和酪蛋白等为主要蛋白质源,配制不含任何大豆抗原蛋白的饲料,命名为DC;以秘鲁鱼粉、肉骨粉和大豆分离蛋白(粗蛋白质含量90%,球蛋白含量179.74 mg/g,β-伴球蛋白含量138.18 mg/g)为主要蛋白质源,配制含有大豆抗原蛋白的饲料,命名为DF,各饲料组成及营养水平见表2。试验1和试验2中饲料氨基酸组成见表3。

表1 试验1饲料组成及营养水平(风干基础) Table 1 Composition and nutrient levels of diets in experiment 1 (air-dry basis)

表2 试验2饲料组成及营养水平(风干基础) Table 2 Composition and nutrient levels of diets in experiment 2 (air-dry basis)

表3 试验1与试验2中饲料的氨基酸组成(风干基础) Table 3 Amino acid composition of diets in experiments 1 and 2 (air-dry basis)

在饲料制作前,所有饲料原料粉碎后过180 μm中药筛,按配方进行称重,用BYM-T50型混合机(东莞市百亿通用机械有限公司)混合15 min,加水经MM-12型绞肉机(韶关市食品机械厂有限公司)挤压成1.2 mm的软颗粒饲料,晾干,装入自封袋室温保存备用。

1.2 饲养管理

试验在上海浦东某试验场(北纬31°00′,东经121°89′)进行。试验虾运输至养殖场前,预先用生石灰对布置网箱的水泥池和暂养池进行消毒。试验虾在暂养池内暂养2周,而后在网箱(1.90 m×1.25 m×1.00 m)内进行养殖试验。暂养期间投喂基础饲料。试验开始前,停食24 h,挑选规格一致,健康无病的试验虾,准确称量试验虾的初始体重为(5.86±0.04) g,随机分为7组,每组设置3个重复,每个重复放养60尾。每天分别在07:00和17:00进行投喂,将饲料放在料台上,投喂量为试验虾体重的3%~5%,表观饱食投喂,并视试验虾摄食情况进行调整。试验为期44 d。

养殖用水为河水,入水口放置双层149 μm筛绢以过滤河水。保持网箱水深(90±1) cm。每天测定水温4次(04:00、08:00、12:00和16:00),水体盐度为0.15‰~0.18‰,养殖期间水温为24.0~30.7 ℃,积温为1 195 ℃;氨氮(NH+4-N)浓度<0.3 mg/L;pH=8.0±0.2,溶解氧(DO)浓度>5 mg/L,昼夜连续充氧。试验开始7 d后,在每次投喂结束50 min后,收集包膜完好的对虾粪便,60 ℃下干燥至恒重。

1.3 样品采集及分析

养殖试验结束后,对试验虾禁食24 h,以重复为单位计数并称总重;随后每个重复随机取9尾虾,测量体长和体重;解剖得到肝胰腺,称重后保存于-20 ℃。

肝胰腺中非特异免疫酶和消化酶活力均采用南京建成生物工程研究所生产的试剂盒测定。组织匀浆液中蛋白质含量测定采用考马斯亮蓝法,方法见说明书。饲料和粪便中的三氧化二铬(Cr2O3)含量采用硝酸和高氯酸消化法预处理[38],并用分光光度法进行测定。

饲料和全虾的水分含量采用96 ℃真空干燥法测定,粗蛋白质含量采用凯氏定氮法(N×6.25)测定,粗脂肪含量采用索氏抽提法(石油醚)测定,粗灰分含量采用高温灼烧法(在马弗炉内600 ℃灼烧6 h)测定。

1.4 计算与统计分析

成活率(survival rate,SR,%)=100×试验结束时虾尾数/试验

开始时虾尾数;

摄食量(feed intake,FI,g)=投饵总量/(试验初始时放虾尾数+试验

结束时虾尾数)/2;

肝胰指数(hepatosomatic index,HSI,%)=100×肝胰腺湿重/虾体湿重;

肥满度(condition factor,CF,g/cm3)=体重/体长3

增重率(weight gain rate,WGR,%)=100×(终末虾均重-初始虾均重)/初始虾均重;

饲料系数(feed conversion ratio,FCR)=摄食量/(终末虾体重-初始虾体重);

特定生长率(specific growth rate,SGR,%/d)=100×(ln终末虾均重-ln初始虾均重)/试验天数;

蛋白质效率(protein efficiency ratio,PER,%)=100×(终末虾体重-初始虾体重)/(摄食量×饲料

粗蛋白质含量);

干物质表观消化率(apparent digestibility of dry matter,ADDM,%)=100×(1-饲料中Cr2O3

含量/粪中Cr2O3含量);

粗蛋白质表观消化率(apparent digestibility of crude protein,ADCP,%)=100×(1-粪中粗蛋白质含量×饲料中Cr2O3含量/饲料中粗蛋白质含量×粪中Cr2O3含量);

粗脂肪表观消化率(apparent digestibility of crude lipid,aDCL,%)=100×(1-粪中粗脂肪含量×饲料中Cr2O3含量/饲料中粗脂肪含量×粪中Cr2O3含量)。

1.5 数据统计

所有数据均用平均值±标准差表示,采用SPSS 17.0统计软件对所得数据进行单因素方差分析(one-way ANOVA),并用Duncan氏法进行多重比较,P<0.05表示差异显著。

2 结 果 2.1 生长性能

投喂不同饲料的南美白对虾的生长性能见表4。

表4 投喂不同饲料的南美白对虾的生长性能 Table 4 Growth performance of L. vannamei fed different diets

试验1:发酵豆粕添加量对增重率、特定生长率和摄食量无显著影响(P>0.05),对饲料系数、蛋白质效率和成活率有显著影响(P<0.05)。随着发酵豆粕添加量的增加,饲料系数呈先降后升趋势,以D5组最低;蛋白质效率呈先升后降趋势,以D5组最高;成活率呈先升后降趋势,以D8组最高。

试验2:大豆抗原蛋白对增重率、特定生长率和摄食量均无显著影响(P>0.05),但DC和DF组的增重率和摄食量均高于D0组;成活率、蛋白质效率和饲料系数各组间均存在显著差异(P<0.05),且均以DF组最高。通过对饲料中球蛋白和β-伴球蛋白含量与对虾的增重率、摄食量及成活率分别进行回归分析,得出饲料中球蛋白(y1)和β-伴球蛋白含量(y2)与对虾增重率(x1)、摄食量(x2)及成活率(x3)的回归方程如下:y1=-0.000 4x21+0.011 3x1+1.045 8(R2=0.878,P=0.015),y1=-0.055 3x2+13.819(R2=0.644,P=0.030),y1=-0.059 3x23+1.338 4x3+72.646(R2=0.561,P=0.193);y2=-0.000 049x31+0.000 7x21+0.004 3x1+1.047 0(R2=0.935,P=0.01),y2=-0.078 4x2+13.842(R2=0.651,P=0.028),y2=-0.118 1x23+1.905 8x3+72.549(R2=0.588,P=0.170)。

2.2 体组成、肝胰指数和肥满度

试验虾摄食不同饲料44 d后,全虾体组成、肝胰指数和肥满度见表5。

表5 投喂不同饲料的南美白对虾的体组成、肝胰指数和肥满度(干物质基础) Table 5 Body composition,HSI and CF of L. vannamei fed different diets (DM basis)

试验1:全虾水分、粗灰分含量和肥满度各组之间均无显著差异(P>0.05)。全虾粗蛋白质含量、肝胰指数均以D8组最高,显著高于除D2组外的其他各组(P<0.05);全虾粗脂肪含量亦是以D8组最高,显著高于D5组(P<0.05)。

试验2:全虾水分、粗灰分含量和肥满度各组之间均无显著差异(P>0.05)。DC和DF组的全虾粗蛋白质含量显著高于D0组(P<0.05);DF组的全虾粗脂肪含量显著低于DC和D0组(P<0.05);DC组的肝胰指数显著高于DF和D0组(P<0.05),DF和D0组之间无显著性差异(P>0.05)。

2.3 营养物质表观消化率

投喂不同饲料的南美白对虾对营养物质的表观消化率见表6。

表6 投喂不同饲料的南美白对虾对营养物质的表观消化率 Table 6 Apparent digestibility of nutrients for L.vannamei fed different diets

试验1:除D15组的干物质表观消化率显著低于D0组(P<0.05)外,其他组与D0组无显著差异(P>0.05);D5组粗蛋白质表观消化率显著低于其余各组(P<0.05);各组对虾的粗脂肪表观消化率无显著差异(P>0.05)。

试验2:干物质和粗蛋白质表观消化率均以DF组最低,并显著低于D0和DC组(P<0.05);各组对虾的粗脂肪表观消化率无显著差异(P>0.05)。

2.4 肝胰腺消化酶活力

投喂不同饲料的南美白对虾的肝胰腺消化酶活力见表7。

试验1:肝胰腺淀粉酶、脂肪酶和胰蛋白酶活力随发酵豆粕添加量的增加均呈先升后降的趋势。除D2组外,其余各组的肝胰腺淀粉酶活力均显著高于D0组(P<0.05),且以D8组最高;肝胰 腺脂肪酶活力以D5组最高,显著高于其他各组 (P<0.05);除D15组的肝胰腺胰蛋白酶活力显著低于D0组(P<0.05),其余各组均显著高于D0组(P<0.05)。

表7 投喂不同饲料的南美白对虾的肝胰腺消化酶活力 Table 7 Digestive enzyme activities in hepatopancreas of L. vannamei fed different diets

试验2:肝胰腺淀粉酶和脂肪酶活力表现为DC组>DF组>D0组,组间差异显著(P<0.05);DC组的肝胰腺胰蛋白酶活力显著低于D0组(P<0.05),但与DF组无显著差异(P>0.05)。

2.5 肝胰腺非特异性免疫酶活力

投喂不同饲料的南美白对虾的肝胰腺非特异免疫酶活力见表8。

表8 投喂不同饲料的南美白对虾的肝胰腺非特异免疫酶活力 Table 8 Non-specific immune enzyme activities in hepatopancreas of L.vannamei fed different diets

试验1:肝胰腺超氧化物歧化酶活力表现为D0组>D2组>D5组>D15组>D8组,组间差异显著(P<0.05);D15组肝胰腺溶菌酶活力显著低于其他各组(P<0.05),且D8组显著低于D0、D2、D5组(P<0.05);肝胰腺碱性磷酸酶活力随发酵豆粕添加量的增加而降低,除D8和D15组差异不显著(P>0.05)外,其他组间差异显著(P<0.05);D2、D5、D8、D15组的肝胰腺谷草转氨酶活力均不同程度低于D0组,其中与D5、D8、D15组的差异达显著水平(P<0.05);肝胰腺谷丙转氨酶活力表现为D2组显著低于其他各组(P<0.05)。

试验2:DC组的肝胰腺超氧化物歧化酶活力显著低于D0和DF组(P<0.05),溶菌酶活力亦不同程度低于D0(P<0.05)和DF组(P>0.05),而碱 性磷酸酶、谷草转氨酶和谷丙转氨酶活力则均显著高于D0和DF组(P<0.05)。

3 讨 论

近几年,关于发酵豆粕在陆生和水生动物饲料中的应用研究呈逐年上升趋势。发酵豆粕作为改性豆粕,其主要优点是抗营养因子含量低、多肽和未知促生长因子的引入。因此,在陆生和水生动物饲料的鱼粉替代研究中,发酵豆粕表现出比豆粕更多的性能优势。然而,抗营养因子种类多,无论是热敏性还是非热敏性抗营养因子,针对于其作用机制或对水生动物生理功能影响的研究鲜见报道。本研究以抗原蛋白(球蛋白和β-伴球蛋白)明显减少的发酵豆粕作为南美白对虾饲料中鱼粉和豆粕的替代源,旨在初步探讨豆粕中的抗原蛋白在替代后可能造成的影响及作用机制。

3.1 大豆抗原蛋白对南美白对虾生长和成活的影响

试验1结果表明,用2%~15%的发酵豆粕替代鱼粉和豆粕(2 ∶ 1),在44 d的养殖周期内,对试验虾的生长无显著影响,但成活率却显著高于D0组,说明发酵豆粕对试验虾的成活有积极的作用,Shiu等[39]提出这可能与豆粕发酵后抗营养因子的减少有关。在试验2中,D0组的成活率显著低于不含大豆抗原蛋白的DC组,证明了大豆抗原蛋白的减少对发酵豆粕成功替代鱼粉和豆粕的贡献;含有大豆抗原蛋白的DF组成活率同时高于D0组和不含抗原蛋白的DC组,显示出抗营养因子作用机理的复杂性,尚待进一步研究。

饲料系数、蛋白质效率和体组成是机体对营养物质综合利用的体现,本研究中上述3个指标虽然对发酵豆粕和大豆抗原蛋白有不同程度的响应,但鉴于复杂的代谢过程,目前未能对具体的变化原因作出解释。

3.2 大豆抗原蛋白对南美白对虾摄食和饲料消化的 影响

发酵豆粕部分替代鱼粉和豆粕,在抗营养因子含量降低的同时,还存在氨基酸等营养组成和风味物质的变化,并可能对试验动物的摄食产生影响。本研究表明,在44 d的养殖周期中,各组摄食量没有显著差异,说明鱼粉和豆粕的减少并没有降低试验饲料的适口性,可能是因为鱼粉、豆粕和发酵豆粕使用量的改变并未引起饲料质构的改变。

饲料进入体内后,动物即开始对营养物质进行消化吸收。本研究中,当发酵豆粕的添加量达到15%时,干物质表观消化率显著低于含有较高大豆抗原蛋白的D0组。同样,DF组的干物质表观消化率也显著低于D0组,这些结果说明大豆抗原蛋白对营养物质的消化吸收有直接的影响。但干物质、粗脂肪和粗蛋白质表观消化率在含有较高大豆抗原蛋白的D0组与不含大豆抗原蛋白的DC组间无显著差异,根据D0组与DF组之间大豆抗原蛋白及其他未知抗营养因子含量的差异,推测营养物质的表观消化率不仅与大豆抗原蛋白的含量有关,与大豆抗原蛋白和其他抗营养因子之间的联合效应也有关。抗营养因子间的协同或拮抗作用还有待进一步研究。

消化酶的分泌影响机体对营养物质的消化吸收。由试验1和试验2结果表明,大豆抗原蛋白含量和及其与其他抗营养因子的联合效应均不同程度影响肝胰腺消化酶活力,且不同于对营养物质表观消化率的影响。宋文新[40]对黑鲷幼鱼的研究得出类似结果,即随发酵豆粕对鱼粉替代量的增加,黑鲷幼鱼肝脏中各消化酶活力与营养物质的表观消化率并无线性关系。Buddington等[41]指出,鱼类会根据饲料的营养水平和品质的不同,调节胰腺对消化酶的分泌,且存在消化酶活力降低而消化酶浓度升高的情况。综合以上结果认为,发酵豆粕对鱼粉和豆粕的替代影响试验虾消化酶的分泌,且与大豆抗原蛋白含量、其他存在于饲料中的未知抗营养因子与大豆抗原蛋白的联合效应有关。至于究竟通过调节消化酶的浓度,还是消化酶的活力或同时调节消化酶的浓度和活力来确保机体对营养物质的消化吸收,尚无相关试验数据或资料可以证实。

在本研究中,肝胰腺淀粉酶和脂肪酶活力的变化除了与大豆抗原蛋白及其他抗营养因子有关外,也可能与饲料中淀粉和脂肪含量有关。王重刚等[42]研究表明,淀粉酶的活力与试验饲料中的淀粉含量呈正相关,而脂肪酶活力与饲料中脂肪含量呈负相关,这与本试验所得出的结果基本相同。

尽管南美白对虾具有调节消化吸收的能力,但调节能力相对有限。当发酵豆粕的添加量达15%时,已表现出干物质表观消化率的显著下降,因此在对鱼粉和豆粕的替代中,应注意发酵豆粕的用量。

3.3 大豆抗原蛋白对南美白对虾非特性免疫酶和健康的影响

饲料营养物质被消化吸收后,将以不同的途径和形式加以利用,从而使机体表现出不同的免疫力水平和健康状况。

对虾作为无脊椎动物,没有特异性淋巴细胞,不能分泌免疫球蛋白[43],体液免疫机制是抵抗病原菌入侵的第1道屏障[44, 45]。碱性磷酸酶可将细胞内代谢废物通过细胞膜转运到细胞外,其活力的升高是肝病病理学原因之一[46]。在甲壳动物及其他动物中,谷丙转氨酶和谷草转氨酶是氨基酸代谢中的2种重要酶,也常用来表征肝胰腺的损伤程度[47, 48]。本研究中,发酵豆粕部分替代鱼粉和豆粕后,肝胰腺碱性磷酸酶、谷草转氨酶和谷丙转氨酶活力下降。由此可以看出,发酵豆粕在饲料中的使用有利于保护试验虾的肝胰腺健康;肝胰腺超氧化物歧化酶和溶菌酶活力均呈下降趋势,表明替代后试验虾只需要较低的基础免疫水平用于维持肝胰腺健康,因此不需要消耗更多的蛋白质用于免疫酶的合成,这将有利于动物的生长。超氧化物歧化酶和溶菌酶活力在不含抗原蛋白的DC组显著低于含抗原蛋白的DF和D0组,证明了豆粕发酵后抗原蛋白消减的积极作用。张加润等[49]研究替代斑节对虾饲料中的鱼粉时,随豆粕添加量的增加,肝胰腺中的超氧化物歧化酶和溶菌酶活力均呈上升趋势,推测可能与植物蛋白质源中抗营养因子含量的增加有关。值得一提的是,试验2中表征肝胰腺健康的碱性磷酸酶、谷草转氨酶和谷丙转氨酶活力并没有出现如试验1随大豆抗原蛋白含量降低而降低的变化,推测大豆抗原蛋白有无与含量高低有着本质的区别。

4 结 论

① 大豆抗原蛋白影响南美白对虾的生长、消化和非特异性免疫。

② 发酵豆粕之所以能部分替代鱼粉和豆粕,与大豆抗原蛋白(球蛋白和β-伴球蛋白)含量的降低保证试验虾的生长、消化和免疫功能有关。

③ 在本试验条件下,南美白对虾饲料中添加不超过15%的发酵豆粕替代鱼粉和豆粕是可行的。

参考文献
[1]D'ABRAMO L R,CONKLIN D E,AKIYAMA D M.Crustacean nutrition[M]. World Aquaculture Society,1997:77. (1)
[2]DAVIS D A,ARNOLD C R.Replacement of fish meal in practical diets for the Pacific white shrimp,Litopenaeus vannamei[J]. Aquaculture,2000,185(3/4):291-298. (1)
[3]AMAYA E A,DAVIS D A,ROUSE D B.Replacement of fish meal in practical diets for the Pacific white shrimp,Litopenaeus vannamei,reared under pond conditions[J]. Aquaculture,2007,262(2/3/4):393-401. (1)
[4]MORALES G A,DE RODRIGAÑEZ M S,MÁRQUEZ L,et al.Solubilisation of protein fractions induced by Escherichia coli phytase and its effects on in vitro fish digestion of plant proteins[J]. Animal Feed Science and Technology,2013,181(1/2/3/4):54-64. (1)
[5]CROMWELL D G.Soybean meal:an exceptional protein source[EB/OL].[2015-01-29] http://www.soymeal.org/ReviewPapers/SBMExceptionalProteinSource.pdf. (1)
[6]RICHARD L,SURGET A,RIGOLET V,et al.Availability of essential amino acids,nutrient utilisation and growth in juvenile black tiger shrimp,Penaeus monodon,following fishmeal replacement by plant protein[J]. Aquaculture,2011,322-323:109-116. (1)
[7]CUMMINS V C,WEBSTER C D,THOMPSON K R,et al.Replacement of fish meal with soybean meal,alone or in combination with distiller's dried grains with solubles in practical diets for Pacific white shrimp,Litopenaeus vannamei,grown in a clear-water culture system[J]. Journal of the World Aquaculture Society,2013,44(6):775-785. (1)
[8]ZHU X Z,DAVIS D A,ROY L A,et al.Response of Pacific white shrimp,Litopenaeus vannamei,to three sources of solvent extracted soybean meal[J]. Journal of the World Aquaculture Society,2013,44(3):396-404. (1)
[9]ALVAREZ J S,HERNÁNDEZ-LLAMAS A,GALINDO J,et al.Substitution of fishmeal with soybean meal in practical diets for juvenile white shrimp Litopenaeus schmitti[J]. Aquaculture Research,2007,38(7):689-695. (1)
[10]YUE Y R,LIU Y J,TIAN L X,et al.Effects of replacing fish meal with soybean meal and peanut meal on growth,feed utilization and haemolymph indexes for juvenile white shrimp Litopenaeus vannamei,Boone[J]. Aquaculture Research,2012,43(11):1687-1696. (1)
[11]SOOKYING D,DAVIS D A.Pond production of Pacific white shrimp (Litopenaeus vannamei) fed high levels of soybean meal in various combinations[J]. Aquaculture,2011,319(1/2):141-149. (1)
[12]SOOKYING D,SILVA F S D,DAVIS D A,et al.Effects of stocking density on the performance of Pacific white shrimp Litopenaeus vannamei cultured under pond and outdoor tank conditions using a high soybean meal diet[J]. Aquaculture,2011,319(1/2):232-239. (1)
[13]FUERTES J B,CELADA J D,CARRAL J M,et al.Effects of dietary protein and different levels of replacement of fish meal by soybean meal in practical diets for juvenile crayfish (Pacifastacus leniusculus,Astacidae) from the onset of exogenous feeding[J]. Aquaculture,2012,364/365:338-344. (1)
[14]MCDONALD P,EDWARDS R A,GREENHALGH J E D,et al.Animal nutrition[M]. 6th ed.Gosport:Pearson Education Ltd.,2002:89. (1)
[15]SUN P,LI D F,DONG B,et al.Effects of soybean glycinin on performance and immune function in early weaned pigs[J]. Archives of Animal Nutrition,2008,62(4):313-321. (1)
[16]CHEN F,HAO Y,PIAO X S,et al.Soybean-derived β-conglycinin affects proteome expression in pig intestinal cells in vivo and in vitro[J]. Journal of Animal Science,2011,89(3):743-753. (1)
[17]GUO P F,PIAO X S,OU D Y,et al.Characterization of the antigenic specificity of soybean protein β-conglycinin and its effects on growth and immune function in rats[J]. Archives of Animal Nutrition,2007,61(3):189-200. (1)
[18]吴莉芳,吴亚男,周敏,等.大豆抗原蛋白对草鱼肌肉营养成分的影响[J]. 吉林农业大学学报,2010,32(2):214-217,220. (1)
[19]吴莉芳,王洪鹤,张东鸣,等.饲料中大豆蛋白对草鱼生长及饲料利用的影响[J]. 华南农业大学学报,2009,30(2):78-81. (1)
[20]吴莉芳,秦贵信,张东鸣,等.饲料大豆蛋白对鲤鱼生长及肌肉营养成分的影响[J]. 西北农林科技大学学报:自然科学版,2008,36(10):67-73,80. (1)
[21]吴莉芳,邹瑞兴,王申,等.大豆主要抗原蛋白对埃及胡子鲇肌肉营养成分的影响[J]. 吉林农业大学学报,2009,31(6):741-745. (1)
[22]HIRABAYASHI M,MATSUI T,YANO H.Fermentation of soybean meal with Aspergillus usamii improves zinc availability in rats[J]. Biological Trace Element Research,1998,61(2):227-234. (1)
[23]HAJEN W E,BEAMES R M,HIGGS D A,et al.Digestibility of various feedstuffs by post-juvenile chinook salmon (Oncorhynchus tshawytscha) in sea water.1.Validation of technique[J]. Aquaculture,1993,112(4):321-332. (1)
[24]EGOUNLETY M,AWORH O C.Effect of soaking,dehulling,cooking and fermentation with Rhizopus oligosporus on the oligosaccharides,trypsin inhibitor,phytic acid and tannins of soybean (Glycine max Merr.),cowpea (Vigna unguiculata L.Walp) and groundbean (Macrotyloma geocarpa Harms)[J]. Journal of Food Engineering,2003,56(2/3):249-254. (1)
[25]LIN H Z,CHEN X,CHEN S S,et al.Replacement of fish meal with fermented soybean meal in practical diets for pompano Trachinotus ovatus[J]. Aquaculture Research,2012,44(1):151-156. (1)
[26]FENG J,LIU X,XU Z R,et al.The effect of Aspergillus oryzae fermented soybean meal on growth performance,digestibility of dietary components and activities of intestinal enzymes in weaned piglets[J]. Animal Feed Science and Technology,2007,134(3/4):295-303. (1)
[27]YAMAMOTO T,IWASHIT Y,MATSUNARI H,et al.Influence of fermentation conditions for soybean meal in a non-fish meal diet on the growth performance and physiological condition of rainbow trout Oncorhynchus mykiss[J]. Aquaculture,2010,309(1/2/3/4):173-180. (1)
[28]WOLFSWINKEL T L.The effects of feeding fermented soybean meal in calf starter on growth and performance of dairy calves[D]. Master Thesis.Ames Iowa:Iowa State University,2009:86-89. (1)
[29]GALIL B S,CLARK P F,CARLTON J T.In the wrong place-alien marine crustaceans:distribution,biology and impacts[M]. London:Springer,2011:490. (1)
[30]ZHANG M L,SUN Y H,CHEN K,et al.Characterization of the intestinal microbiota in Pacific white shrimp,Litopenaeus vannamei,fed diets with different lipid sources[J]. Aquaculture,2014,434:449-455. (1)
[31]冷向军,王文龙,李小勤.发酵豆粕部分替代鱼粉对凡纳滨对虾的影响[J]. 粮食与饲料工业,2007(3):40-41. (1)
[32]李贵生,徐金龙.发酵豆粕与发酵杂粕代替部分鱼粉饲养凡纳滨对虾的比较[J]. 暨南大学学报:自然科学版,2011,33(3):311-315. (1)
[33]杨耐德,符广才.凡纳滨对虾饲料中发酵豆粕替代鱼粉的研究[J]. 饲料工业,2008,29(10):24-26. (1)
[34]NRC.Nutrient requirements of fish and shrimp[S]. Washington,D.C.:National Academies Press,2011. (1)
[35]MERRILL A L,WATT B K.Energy value of foods:basis and derivation[M]. Washington,D.C.:United States Department of Agriculture Handbook,1973,74:2. (1)
[36]MACIAS-SANCHO J,POERSCH L H,BAUER W,et al.Fishmeal substitution with Arthrospira (Spirulina platensis) in a practical diet for Litopenaeus vannamei:effects on growth and immunological parameters[J]. Aquaculture,2014,426-427:120-125. (1)
[37]BAUER W,PRENTICE-HERNANDEZ C,TESSER M B,et al.Substitution of fishmeal with microbial floc meal and soy protein concentrate in diets for the pacific white shrimp Litopenaeus vannamei[J]. Aquaculture,2012,342-343:112-116. (1)
[38]GRANT G.Anti-nutritional effects of soyabean:a review[J]. Progress in Food and Nutrition Science,1989,13(3/4):317-348. (1)
[39]SHIU Y L,WONG S L,GUEI W C,et al.Increase in the plant protein ratio in the diet of white shrimp,Litopenaeus vannamei (Boone),using Bacillus subtilis E20-fermented soybean meal as a replacement[J]. Aquaculture Research,2015,46(2):382-394. (1)
[40]宋文新.黑鲷幼鱼饲料中发酵豆粕部分替代鱼粉的研究[D]. 硕士学位论文.杭州:浙江大学,2011:31-33. (1)
[41]BUDDINGTON R K,KROGDAHL A,BAKKE-MCKELLEP A M.The intestines of carnivorous fish:structure and functions and the relations with diet[J]. Acta Physiologica Scandinavica Supplementum,1997,638:67-80. (1)
[42]王重刚,陈品健,顾勇,等.不同饵料对真鲷稚鱼消化酶活性的影响[J]. 海洋学报,1998,20(4):103-106. (1)
[43]LEE Y S,SÖDERHÄLL K.Early events in crustacean innate immunity[J]. Fish & Shellfish Immunology,2002,12(5):421-437. (1)
[44]HIKIMA S,HIKIMA J,ROJTINNAKORN J,et al.Characterization and function of kuruma shrimp lysozyme possessing lytic activity against Vibrio species[J]. Gene,2003,316:187-195. (1)
[45]KUNLAYA S,PREMRUETHAI S,VICHIEN R,et al.Differentially expressed genes in hemocytes of Vibrio harveyi-challenged shrimp Penaeus monodon[J]. Journal of Biochemistry and Molecular Biology,2006,39(1):26-36. (1)
[46]GIANNINI E G,TESTA R,SAVARINO V.Liver enzyme alteration:a guide for clinicians[J]. Canadian Medical Association Journal,2005,172(3):367-379. (1)
[47]CHAPLIN A E,HUGGINS A K,MUNDAY K A.The distribution of L-α-aminotransferases in Carcinus maenas[J]. Comparative Biochemistry and Physiology,1967,20(1):195-198. (1)
[48]DENG S X,TIAN L X,LIU F J,et al.Toxic effects and residue of aflatoxin B1 in tilapia (Oreochromis niloticus×O.aureus) during long-term dietary exposure[J]. Aquaculture,2010,307(3/4):233-240. (1)
[49]张加润,林黑着,黄忠,等.饲料中用混合植物蛋白并添加氨基酸替代鱼粉对斑节对虾生长及免疫力的影响[J]. 南方水产科学,2013,9(5):44-50. (1)