饲料中胆汁酸添加水平对牛蛙肝脏化学组成、抗氧化和代谢酶活力的影响

试验将144只(初始质量75.01 g±4.23 g)牛蛙(Rana catesbeiana)随机分在12个玻璃水族缸中,每组3个重复,每个重复12只牛蛙。分别向每千克基础饲料中添加0、100、200和300 mg胆汁酸,配制成4种等氮等能的试验饲料。试验期8周。结果表明:1)饲料中添加100 mg/kg的胆汁酸显著降低肝脏粗脂肪含量,升高水分含量。2)随着胆汁酸添加量的增加,超氧化物歧化酶(SOD)呈先升高后降低的趋势,添加量为200 mg/kg时最高;添加胆汁酸显著提高了谷胱甘肽过氧化物酶(GSH-Px)活力;添加200 mg/kg的胆汁酸显著降低了丙二醛(MDA)含量,当添加量为300 mg/kg,MDA显著升高。3)肝脏谷草转氨酶随着胆汁酸含量的升高呈先升高后降低趋势,其中添加量200 mg/kg时最高,各添加水平对谷丙转氨酶活力无显著影响;添加100和200 mg/kg胆汁酸显著降低肝酯酶(HL)和脂蛋白酯酶(LPL)活力。4)饲料中添加300 mg/kg的胆汁酸组牛蛙肝脏颜色呈紫黑色,有白斑,肝脏质地硬。综上,饲料中添加适量的胆汁酸能通过调节牛蛙肝脏脂类代谢水平和抗氧化能力以维持肝细胞的正常功能,建议胆汁酸添加量以不超过200 mg/kg为宜。     

豆粕替代鱼粉对牛蛙生长、体组成、消化酶活力及肝脏生化指标的影响

为减少牛蛙饲料鱼粉使用量以降低养殖成本,研究了豆粕替代饲料中不同比例的鱼粉对牛蛙的生长性能、体组成、肠道消化酶活力和肝脏生化指标的影响。用豆粕分别替代0%、20%、40%、60%、80%和100%的鱼粉配制出6种等氮等能的实验饲料,每组饲料设3重复,养殖牛蛙60 d。结果显示,豆粕替代鱼粉对牛蛙摄食率、成活率、肝体指数、脏体指数、蛙体水分和灰分含量、蛙腿肌肉组成以及肝脏丙二醛含量的影响不显著;豆粕100%替代鱼粉显著降低牛蛙增重率、特定生长率、饲料系数、蛋白质效率、蛋白质累积率;随豆粕替代鱼粉比例的提高,牛蛙的肥满度和后腿指数呈下降趋势,替代100%鱼粉显著降低牛蛙肥满度,替代60%鱼粉显著降低牛蛙后腿指数;替代80%鱼粉显著降低牛蛙全体粗蛋白的含量;牛蛙全体粗脂肪含量随替代鱼粉比例的提高呈上升的趋势,替代100%鱼粉组粗脂肪含量最高;随着替代比例的提高,牛蛙肠道蛋白酶的活力显著降低,而肠道淀粉酶和脂肪酶活力显著提高。豆粕替代鱼粉显著影响肝脏超氧化物歧化酶和过氧化氢酶活力,其中超氧化物歧化酶活力最低值出现在替代80%鱼粉组,过氧化氢酶活力最低值出现在替代100%鱼粉组。基于以上实验结果,建议牛蛙饲料中豆粕可替代鱼粉的比例为60%~80%。     

复合蛋白替代鱼粉对花鲈生长、消化能力和肠道健康的影响

以初均重为(5.80±0.07) g的花鲈(Lateolabrax maculatus)幼鱼为实验对象,研究复合蛋白替代鱼粉对花鲈生长、消化和肠道健康的影响。用复合蛋白分别替代对照组饲料中0、20%、40%、60%和80%的鱼粉,配制成5种等氮等脂的实验饲料,分别用这5种饲料投喂花鲈70 d;养殖实验期间水温为(29.5±1.5)℃,盐度为29±1,溶解氧≥6.5 mg/L。养殖实验结束后采集样品进行分析,结果显示,20%替代组花鲈生长性能与对照组无显著差异(P>0.05),但随鱼粉替代比例的升高,花鲈增重率(WGR)、存活率(SR)、饲料效率(FE)以及蛋白质效率(PER)显著下降(P<0.05),花鲈肠道蛋白酶活性以及饲料干物质、粗蛋白与粗脂肪表观消化率皆显著降低(P<0.05),且花鲈后肠黏膜组织结构出现损伤,肠道促炎因子TNF-α、IL-1β基因表达量升高,抗炎因子基因IL-4、IL-10表达量相应降低。研究表明,复合蛋白替代花鲈饲料中鱼粉比例不宜超过20%。     

豆粕替代鱼粉对牛蛙生长、体组成、消化酶活力及肝脏生化指标的影响

为分析泰国虎纹蛙 (Hoplobatrachus tigerinus) 和牛蛙 (Lithobates catesbeiana) 的肌肉品质、肠道形态及微生物构成,采用食品安全国家标准测定方法对这两种养殖蛙的肌肉营养成分进行监测,结合肌肉质构和显微结构的分析对两者肌肉品质进行评价,同时利用高通量测序和组织学切片技术对两者肠道微生物群落构成和显微结构进行分析。结果显示,泰国虎纹蛙和牛蛙氨基酸总量差异不显著 (P>0.05);牛蛙的不饱和脂肪酸含量显著高于泰国虎纹蛙 (P<0.05)。此外,牛蛙肌肉的硬度、咀嚼性和胶黏性均显著高于泰国虎纹蛙 (P<0.05)。肠道微生物分析显示,泰国虎纹蛙的Shannon、Ace和Chao1指数均显著高于牛蛙 (P<0.05);门水平上,牛蛙的厚壁菌门丰度显著高于泰国虎纹蛙 (P<0.05),而放线菌门丰度显著低于后者 (P<0.05);属水平上,泰国虎纹蛙的乳球菌属 (Lactococcus) 和埃希杆菌-志贺菌属 (Escherichia-Shigella)丰度显著高于牛蛙 (P<0.05),而乳杆菌属 (Lactobacillus) 和明串珠菌属 (Leuconostoc) 丰度显著低于后者 (P<0.05)。研究表明,泰国虎纹蛙和牛蛙肌肉品质存在差异,但营养价值均较高;高通量测序分析显示两者肠道微生物群落组成存在差异。

     

牛蛙腹水病病原鉴定和药敏试验

从患病牛蛙(Rana catesbeiana)肝脏、四肢、腹水等组织划线分离,共获得3株菌,通过对菌落形态观察、革兰氏染色镜检及生理生化鉴定,确认其理化性质一致,均为洛菲不动杆菌(Acinetobacter lwoffi)。采取腹部注射和浸泡两种不同方式人工感染试验均证实该菌存在致病性,药敏试验表明,分离菌株W2011-01对左氟沙星、美洛培南、哌拉西林/他唑巴坦、妥布霉素、复方新诺明、庆大霉素等18种药物敏感,对呋喃妥因、环丙沙星、沙拉沙星、乙酰螺旋霉素、青霉素、杆菌肽、痢特灵、利福平、氨苄西林、强力霉素耐药。     

豆粕替代鱼粉对青鱼幼鱼生长及生理生化指标的影响

以初始体重(5.90±0.01)g的青鱼(Mylopharyngodon piceus)为研究对象,用豆粕替代不同水平鱼粉,配制5种等氮等能的实验饲料,分别为30%鱼粉(对照组)、25%鱼粉、20%鱼粉、15%鱼粉和15%鱼粉+晶体氨基酸,试验持续8周。结果显示:当鱼粉含量为15%时,其增重率、特定生长率、肌肉鲜味氨基酸含量和总氨基酸含量显著低于对照组,而饲料系数则显著高于对照组,添加晶体氨基酸对青鱼生长无显著改善;各处理组间甘油三酯(TG)、总蛋白(TP)、总胆固醇(TC)含量及谷丙转氨酶(ALT)活性无显著差异,但15%鱼粉组和15%鱼粉+晶体氨基酸组的青鱼的血糖含量和谷丙转氨酶活性显著高于对照组。结果表明,青鱼幼鱼实用饲料中鱼粉含量以不低于20%为宜,添加晶体氨基酸对青鱼幼鱼的生长无改善作用。     

牛蛙背部肿胀病的病原菌分离与鉴定及药敏实验

在广东广州番禺某牛蛙养殖场发现较为特殊的疾病且传染率和死亡率较高,为查明其致病原,从患病牛蛙(Rana catesbeiana)中抽取其背部的积液和对其他病变部位如肝、脾等进行细菌的分离纯化后得到两株优势菌,然后将两株优势菌进行16S rRNA基因测序、进化树构建、革兰氏染色细菌和生理生化实验进行鉴定和分析,结果显示一株菌株GPY923为嗜水气单胞菌(Aeromonas hydrophila),另一株菌株GPY924为海豚链球菌(Streptococcus iniae),进行人工感染后表明其具有较强的致病性。药敏试验结果显示嗜水气单胞菌对丁胺卡那、红霉素、头孢他啶、头孢呋辛、青霉素和氟苯尼考敏感,对多种药物耐药;海豚链球菌对林可霉素和头孢呋辛耐药,对头孢他啶中度敏感,其余药物均敏感。     

豆粕替代鱼粉对鲤鱼生长的影响

以鱼粉和豆粕作为蛋白源。以植物蛋白分别替代0.14％,28％,42％,56％,71％,86％和100％的动物蛋白设计出等蛋白（30％左右）等能（15．77kJ／g左右）的8种不同动植物蛋白比饲料。通过65d的养殖,结果表明：鲤鱼的特定生长率在豆粕替代鱼粉比例71％时为0．82％／d,除与豆粕替代比例为0时的试验组无显著差异外（P〉0．05）,显著大于其余各试验组（P〈0．05）;蛋白效率在豆粕替代鱼粉比例86％时最大,分别为1.29％,除与豆粕替代比例71％时差异不显著外（P〉0．05）,与其余试验组差异显著（P〈0．05）;饵料系数在豆粕替代鱼粉比例86％时最小为2．42,与豆粕替代比例71％时差异不显著外（P〉0．05）,但与试验组差异显著（P〈0．05）。则本试验中动植物蛋白比为0．37：1-0．18：1时,鲤鱼的生长能达到较好的效果。     

发酵豆粕替代鱼粉对斑点叉尾鲴消化酶活性的影响

以发酵豆粕替代基础日粮中25％、50％、75％和100％的鱼粉,饲养平均体重为1．1g的斑点叉尾鲴42d后,研究了发酵豆粕对斑点叉尾鲴生长和消化酶活性的影响。结果显示：发酵豆粕替代25％、50％、75％鱼粉组斑点叉尾鲴增重率、特定生长率比对照组稍高（P〉0．05）,饲料系数与对照组没有显著性差异（P〉0．05）;替代100％的鱼粉时,这些指标与对照组也没有显著性差异;试验组斑点叉尾鲴胃蛋白酶活性与对照组无显著性差异（P〉0．05）;肝胰脏和肠道的蛋白酶活性随着替代比例的提高而呈不明显的上升趋势（P〉0．05）;各试验组鱼淀粉酶活性均高于对照组,其中以替代50％鱼粉组最高,但差异不显著（P〉0．05）。     

发酵豆粕替代鱼粉对斑点叉尾鮰消化酶活性的影响

以发酵豆粕替代基础日粮中25%、50%、75%和100%的鱼粉,饲养平均体重为1.1g的斑点叉尾鮰42d后,研究了发酵豆粕对斑点叉尾鮰生长和消化酶活性的影响.结果显示:发酵豆粕替代25%、50%、75%鱼粉组斑点叉尾鮰增重率、特定生长率比对照组稍高(P>0.05),饲料系数与对照组没有显著性差异(P>0.05);替代100%的鱼粉时,这些指标与对照组也没有显著性差异;试验组斑点叉尾鮰胃蛋白酶活性与对照组无显著性差异(P>0.05);肝胰脏和肠道的蛋白酶活性随着替代比例的提高而呈不明显的上升趋势(P>0.05);各试验组鱼淀粉酶活性均高于对照组,其中以替代50%鱼粉组最高,但差异不显著(P>0.05).     

Effects of replacing fish meal with soybean meal on growth,body composition and digestive enzyme activities of juvenile Chinese sucker,Myxocyprinus asiaticus

Six isonitrogenous diets (420 g kg^?1 crude protein on dry matter basis) with six levels of soybean meal (SBM) inclusion (0, 112, 225, 336, 449 and 560 g kg^?1) in substitution of fish meal (0%, 20%, 40%, 60%, 80% and 100%) were evaluated in Chinese sucker of 1.81 ± 0.01 g initial weight for 8 weeks. There existed a significant difference (P < 0.001) in fish weight gain, feed conversion ratio, feed intake, protein efficiency ratio and specific growth rate when the replacement level for fish meal protein was increased from 40% to 60%, indicating that up to 40% of fish meal protein could be replaced with SBM protein without causing reduction in growth and protein utilization. Lipid contents in the Chinese sucker body decreased significantly (P < 0.001) as dietary SBM increased. Digestive enzyme activities in the intestine and hepatopancreas of the fish were significantly different (P < 0.001) as the SBM protein replacement level was increased. Results of the present study appear to indicate that 40% FM can be replaced by SBM in practical feeds of Chinese sucker.     

大豆替代豆粕对中华绒螯蟹生长、消化酶活力和抗氧化能力的影响

为探讨中华绒螯蟹幼蟹的饲料大豆替代豆粕的适宜替代量,配制4种不同替代水平(0、40%、60%和80%)的等氮等能饲料,饲喂初重(5.34±0.19)g的中华绒螯蟹幼蟹5个月,测定其生长性能、消化酶活性和抗氧化能力。结果显示,各组蟹的增重率、饲料系数和存活率差异不具统计学意义(P>0.05);随着大豆替代豆粕的比例上升,蟹肝胰腺胰蛋白酶、脂肪酶和淀粉酶水平呈显著下降趋势(P<0.05);各组蟹肝胰腺超氧化物歧化酶、过氧化氢酶及总抗氧化活力的水平差异均不具统计学意义(P>0.05)。综上所述,饲料中用大豆替代40%~80%的豆粕不会显著影响中华绒螯蟹的生长性能和抗氧化能力,但是对机体的消化酶有一定的负面影响。     

Effects of fish meal replaced by fermented soybean meal on growth performance,intestinal histology and microbiota of largemouth bass (Micropterus salmoides)

This study was conducted to investigate the effects of replacing fish meal (FM) with fermented soybean meal (FSM) and soybean meal (SM) on growth performance, intestinal histology and microbiota of largemouth bass (Micropterus salmoides). The basal diet contained 350 g/kg FM (CON), and then, FM was replaced with SM and FSM at the ratios of 30% and 60% (SM‐30, SM‐60, FSM‐30 and FSM‐60), respectively. The largemouth bass (4.43 ± 0.13 g) were fed for 8 weeks. The results showed that weight gain of fish fed with FSM‐60 and SM‐60 diets was significantly lower, and feed conversion ratio of SM‐30, SM‐60 and FSM‐60 groups was significantly higher than the CON group (p < .05). The intestinal villus height of SM‐60 group and the villus width of SM‐60 and FSM‐60 group were significantly lower than the CON group (p < .05). The 30% FM replacement by SM and FSM significantly increased the abundance of Cetobacterium and Mycoplasma, respectively (p < .05). In conclusion, FSM could replace 30% FM in diet without negative impacts on the growth performance of largemouth bass, while the SM should be controlled below 30%.     

国产鸡肉粉替代鱼粉对大口黑鲈生长性能、肝脏健康及肠道屏障的影响

为评价鸡肉粉替代鱼粉的可行性,用不同水平国产鸡肉粉(PBM)等蛋白替代基础饲料中的鱼粉,配制成5种等氮等脂的实验饲料(对照组、PBM 12.5、PBM 25.0、PBM 37.5及PBM 50.0),在室内循环系统饲喂初始体重为(9.25±0.13) g的大口黑鲈8周。结果显示,各处理组大口黑鲈的增重率(WGR)、特定生长率(SGR)和摄食率(FR)均无显著差异。同对照组相比,实验组肝脏超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性显著增加,而丙二醛(MDA)含量显著降低。随鸡肉粉替代水平的增加,肝脏抗炎细胞因子基因(IL-10、TGF-β)相对表达量显著上调,而促炎细胞因子基因(IL-8、TNF-α)相对表达量显著下调,但肝脏的组织结构无显著临床症状变化。此外,随替代水平的增加,肠道抗氧化基因(sod、cat)和肠道紧密连接蛋白基因(Occludin、ZO-1和Claudin-1)相对表达量也显著上调,而血清D-乳酸(D-lac)和脂多糖(LPS)含量显著降低。研究表明,鸡肉粉替代基础饲料(基础饲料中含有40%的鱼粉) 50%的鱼粉不会抑制大口黑鲈的生长,同时还会增强鱼体的抗氧化...     

Effects of replacing fish meal with soybean meal,with or without dietary arginine,on growth performance,immune indices and intestinal morphology of grouper,Epinephelus malabaricus

A 10‐week feeding experiment was conducted to evaluate the effects of replacing fish meal with soybean meal (SBM), with or without dietary arginine (Arg), on growth performance, immune indices and intestinal morphology of grouper, Epinephelus malabaricus. Nine experimental diets were formulated to contain 20%, 30% and 40% fish meal protein (FMP) replaced using SBM and 0, 0.5% and 1% dietary Arg supplementation. The results showed that weight gain (WG) of fish was significantly affected by the interaction of substitution level and Arg supplemental level. The maximum WG occurred at the 30% FMP substitution level and the 0.5% Arg supplemental level. The immune assay showed that the interaction between the two levels significantly influenced the production of serum nitric oxide but did not affect serum IgG concentration and alkaline phosphatase activity or the liver IGF‐1 gene expression. Significant interaction effects between the two levels were observed in muscle layer thickness (tML) and fold height (hF) in the proximal and mid‐intestine. High SBM level in diets reduced the tML and hF in the entire intestine. The results suggested that the interaction of 30% FMP substitution level and Arg supplemental level of 0.5% most benefitted growth performance, immune indices and intestinal structure of grouper.     

Effects of fish meal replacement by soybean meal with supplementation of functional compound additives on intestinal morphology and microbiome of Japanese seabass (Lateolabrax japonicus)

A 15‐week trial was carried out to estimate the effects of functional compound additives (FCA) on intestinal morphology and microbiome in Japanese seabass, Lateolabrax japonicus, fed diets with soybean meal (SBM) partially replacing fish meal (FM). The formulation of FCA was the mixture of antioxidant, immunopotentiator and Mintrex^® trace elements. Four isonitrogenous (45%) and isolipidic (11%) diets, including FM42 (the control group without FCA), FM35 (15% FM protein substitution level with FCA), FM21 (50% FM protein substitution level with FCA) and FM21‐N (50% FM protein substitution level without FCA) were formulated. Quadruplicate groups of seabass (initial average weight 125.65 ± 0.60 g) were randomly handfed each diet twice daily in seawater floating cage. No significant differences were found in microvillus height (HMV) and muscular thickness (MT) of distal intestine among fish fed FM42, FM35 and FM21, whereas the HMV, MT and fold height (HF) in seabass fed FM42 were significantly higher than those of seabass fed FM21‐N (P < 0.05). Seabass fed FM21‐N had more obvious enteritis parameters such as tissue disruption, wider lamina propria and less mucosal fold than those in seabass fed FM21. High‐throughput sequencing technology of gut flora showed that Proteobacteria was the most dominant bacteria at phylum level among groups. There was no significant difference in relative abundance and composition of gut microflora among groups. In conclusion, supplementation of FCA might partially eliminate SBM‐induced enteritis, but the composition and relative abundance of intestinal microflora were not affected by dietary treatments.     

Effects of fish origin probiotics on growth performance,immune response and intestinal health of shrimp (Litopenaeus vannamei) fed diets with fish meal partially replaced by soybean meal

This study was conducted to evaluate the application of four fish origin probiotics to relieve the side effects induced by SBM in shrimp. Shrimps were fed with high fish meal diet (C0, positive control containing 500 g/kg FM and 0 g/kg SBM), low fish meal diet (C, control containing 250 g/kg FM and 340 g/kg SBM) or the control diet (C) supplemented, respectively, with 1.0 × 10⁸ CFU/g Bacillus pumilus SE5 (T1), Psychrobacter sp. SE6 (T2), Enterococcus faecium MM4 (T3) or Bacillus claussi DE5 (T4). After 6 weeks of feeding, the growth performance, hepatopancreatic digestive enzymes, intestinal histological structure and immune parameters were determined. The results showed that compared with high FM group (C0), significantly lower WGR and SGR as well as higher FCR were observed in the low FM group (C) (p < .05). Compared with the control, significantly lower FCR was observed in treatment T1 (p < .05), but not in treatments T2–T4. Protease, amylase and lipase activities in all the treatments (T1‐T4) were significantly higher than the control (p < .05). GOT and GPT activities in the control were significantly lower than the C0 (p < .05), while higher MDA level was recorded in the control (p < .05). Meanwhile, higher GPT activities were observed in treatments T1‐T4 compared with the control (p < .05). Compared with the C0, lower SOD, ACP and AKP activities were observed in the control. Significantly improved SOD and AKP activities were observed in all probiotic feeding groups compared with the control (p < .05). The control diet led to significant reduction of intestinal wall thickness and villus height compared with the C0 (p < .05), while significantly higher intestinal wall thickness and villus height were exhibited in all the probiotic groups compared with the control (p < .05), except intestinal wall thickness in treatment T3. Thus, these results demonstrated that the four fish origin probiotic strains could relieve the side effects induced by high level of SBM in shrimp, while probiotic B. pumilus SE5 showed the best performance.     

Histomorphology of gastrointestinal tract in bullfrog Rana (Lithobates) catesbeiana and evaluation of the changes induced by a soybean meal‐based diet

Two studies were carried out to (a) characterize the gastrointestinal (GI) tract of bullfrog Rana (Lithobates) catesbeiana and (b) to evaluate the effects of total replacement of fish meal (FM) with soybean meal (SBM) on GI tract health. For characterization of the GI tract, oesophagus, stomach and intestine sections were sampled from 20 bullfrogs (80 g) fed a FM‐based diet. The results revealed that the GI tract of bullfrog is consisted of four tissue layers including mucosa, submucosa, muscularis and serosa, and that the intestine could be divided into duodenum, jejunum, ileum and rectum. Furthermore, the abundance and length of mucosal folds suggested that jejunum is the primary site of digestion and absorption of nutrients. In the second study, a diet containing 44% fish meal (FM) was formulated and used as a FM‐based diet, and a SBM‐based diet was prepared by entire substitution of FM with SBM. Sixty bullfrogs (35 ± 1 g) were divided into three replicates of the two groups and were fed the test diets to apparent satiation twice daily for 8 weeks. The changes in pH and morphology of GI tract in response to the shift in dietary protein source were evaluated. The results showed the enhancement of pH values in GI tract of the SBM group excluding cardia, jejunum and rectum. Also, SBM diet triggered significant decreases in the number, height and width of mucosal folds, while an opposite trend was observed for thickness of lamina propria. Moreover, the entire replacement of FM with SBM led to the separation of submucosa from muscularis and incidence of lesion in mucous epithelium. The findings in this study showed that jejunum is the main site of nutrients digestion and absorption. Also, it was demonstrated that entire replacement of FM with SBM adversely influenced the GI tract health in bullfrog.     

发酵豆粕部分替代鱼粉对日本鳗鲡生长性能和体内矿物元素的影响

在日本鳗鲡（Anguill japonica）饲料中分别添加0、50 g·kg-1、100 g·kg-1、150 g·kg-1和200 g·kg-1的发酵豆粕,相应替代饲料中鱼粉使用量的0、5%、10%、15%和20%,饲养体质量为（37.62±0.16）g日本鳗鲡50 d,研究发酵豆粕对鳗鱼生长性能和体内矿物元素的影响。结果显示：1）随着发酵豆粕替代鱼粉的比例升高,鳗鱼增重率和特定生长率呈先上升后下降的趋势,其中15%替代组增重率和特定生长率高于其他组,但差异不显著（P﹥0.05）,5%替代组饲料系数显著低于其他组（P〈0.05）。从生长性能上看,15%是发酵豆粕替代鳗鱼饲料中鱼粉的最适比例;2）发酵豆粕替代鱼粉后鳗鱼饲料中的钾（K）、铁（Fe）、镁（Mg）等元素质量分数升高,而铝（Al）元素质量分数降低,按变化幅度大小排列Al〉K〉铜（Cu）〉硼（B）〉钙（Ca）〉钠（Na）〉磷（P）〉Fe,但替代组与对照组鳗鱼肌肉中矿物元素K、Ca和P差异不显著（P〉0.05）,而无论是肌肉还是皮肤中矿物元素Cu质分数量均降低（P〈0.05）,因此,发酵豆粕替代鱼粉后应对饲料中矿物元素添加量适当进行调整。