Physical and chemical changes of rapeseed meal proteins during toasting and their effects on in vitro digestibility

Background： Toasting during the production of rapeseed meal（RSM） decreases ileal crude protein（CP） and amino acid（AA） digestibility. The mechanisms that determine the decrease in digestibility have not been fully elucidated. A high protein quality, low-denatured, RSM was produced and toasted up to 120 min, with samples taken every 20 min. The aim of this study was to characterize secondary structure and chemical changes of proteins and glucosinolates occurring during toasting of RSM and the effects on its in vitro CP digestibility.Results： The decrease in protein solubility and the increase of intermolecular β-sheets with increasing toasting time were indications of protein aggregation. The contents of NDF and ADIN increased with increasing toasting time.Contents of arginine, lysine and O-methylisourea reactive lysine（OMIU-RL） linearly decreased with increasing toasting time, with a larger decrease of OMIU-RL than lysine. First-order reactions calculated from the measured parameters show that glucosinolates were degraded faster than lysine, OMIU-RL and arginine and that physical changes to proteins seem to occur before chemical changes during toasting. Despite the drastic physical and chemical changes noticed on the proteins, the coefficient of in vitro CP digestibility ranged from 0.776 to 0.750 and there were no effects on the extent of protein hydrolysis after 120 min. In contrast, the rate of protein hydrolysis linearly decreased with increasing toasting time, which was largely correlated to the decrease in protein solubility, lysine and OMIU-RL observed. Rate of protein hydrolysis was more than 2-fold higher for the untoasted RSM compared to the 120 min toasted material.Conclusions： Increasing the toasting time for the production of RSM causes physical and chemical changes to the proteins that decrease the rate of protein hydrolysis. The observed decrease in the rate of protein hydrolysis could impact protein digestion and utilization.

Effects of Dietary Corn Gluten Meal on Growth Performance and Protein Metabolism in Relation to IGF-I and TOR Gene Expression of Juvenile Cobia (Rachycentron canadum)

A growth experiment was conducted on cobia(Rachycentron canadum,initial weight 108.2 g ± 3.0 g) to investigate the effects of dietary corn gluten meal(CGM) levels on the fish growth,whole body composition and protein metabolism in relation to specific gene expression.Five isonitrogenous(crude protein 45%) and isoenergetic(gross energy 20 kJ g 1) practical diets were formulated by replacing 0%(the control),17.5%,35.0%,52.5%,and 70.0% of fish meal(FM) protein with CGM protein.No significant differences were observed in the survival,feed intake(FI),specific growth rate(SGR),feed efficiency(FE) and protein productive value(PPV) among fish fed diets with 0%,17.5%,35.0%,and 52.5% of CGM protein.However,these indices were significantly lower in fish fed the diet with 70.0% of CGM protein than those in fish fed the control diet(P < 0.05).The whole-body crude protein and lipid contents were significantly lower while the whole-body moisture content was significantly higher in fish fed the diet with 70.0% of CGM protein compared with the control group(P < 0.05).When 70.0% of FM protein was replaced by CGM,plasma total protein and cholesterol contents were significantly lower than those in the control group(P < 0.05).Fish fed the diet with 70.0% of CGM protein had significantly lower hepatic insulin-like growth factor I(IGF-I) expression levels than those in the control group(P < 0.05).However,no significant differences were observed in hepatic target of rapamycin(TOR),dorsal muscle IGF-I and TOR expression levels among dietary treatments.Results of the present study indicated that 52.5% of FM protein could be replaced by CGM in the diets without significant influences on the growth,feed utilization and protein metabolism of juvenile cobia.The present results might be useful for developing cost effective and sustainable cobia dietary formulations.

Effect of the desolventizing/toasting process on chemical composition and protein quality of rapeseed meal

Background： During processing in a desolventizer/toaster（DT）, rapeseed meal（RSM） is heated to evaporate the hexane and to reduce the level of heat-labile anti-nutritional factors such as glucosinolates（GSL）. However, excessive heat treatment may reduce amino acid（AA） content in addition to lower AA digestibility and availability in RSM. The objective of the present study was to produce from one batch of a 00-rapeseed variety（17 μmol GSL/g dry matter（DM）, seed grade quality） five differently processed RSM under standardized and defined conditions in a pilot plant,and to determine the impact of these different treatments on protein solubility and chemical composition, in particular with regard to contents of AA including reactive Lys（rL ys） and levels of total and individual GSL.Methods： Four RSM were exposed to wet toasting conditions（WetT C） with increasing residence time in the DT of 48,64, 76, and 93 min. A blend of these four RSM was further processed, starting with saturated steam processing（〈 100 °C）and followed by exposure to dry toasting conditions（DryT C） to further reduce the GSL content in this RSM.Results： The contents of neutral detergent fiber and neutral detergent fiber bound crude protein（CP） increased linearly（P 〈 0.05）, as residence time of RSM in the DT increased from 48 to 93 min, whereas contents of total and most individual GSL and those of Lys, rL ys, Cys, and the calculated ratio of Lys：CP and r Lys：CP decreased linearly（P ≤ 0.05）.The combination of wet heating and DryT C resulted in the lowest GSL content compared to RSM produced under WetT C, but was associated with lowest protein solubility.Conclusions： It can be concluded that by increasing residence time in the DT or using alternative processing conditions such as wet heating combined with DryT C, contents of total and individual GSL in RSM can be substantially reduced.Further in vivo studies are warranted to elucidate if and to which extent the observed differences in protein quality and GSL content between RSM may affect digestibility and bioavailability of AA in monogastric animals.

Effect of High-Protein Breakfast Meals on Within-Day Appetite and Food Intake in Healthy Men and Women

Breakfast is considered an important meal for daily appetite control. We examined the effect of high-protein breakfasts on within-day appetite sensations and subsequent ad libitum intake, in men and women. Twenty subjects attended on 4 occasions, to consume in a randomised order high-protein (30% energy) breakfast meals, as, 1) maintenance (MTD) fed to energy requirements (2.67 MJ), 2) a weight-loss (WL) bacon-based meal breakfast (WL-B, 2.13 MJ), 3) a WL-chicken salad (WL-CS, 2.13 MJ) and 4) a WL-smoothie (WL-S, 2.08 MJ). The 3 HP-WL breakfasts elicited differences in hunger (p = 0.007), fullness (p = 0.029), desire to eat (p = 0.006) and prospective consumption (p = 0.020). The WL-B meal reduced hunger (p = 0.002) and enhanced fullness (p = 0.02), compared with the two other WL breakfasts. Although these differences were not reflected in ad libitum energy intake later in the day, a HP breakfast can modify morning satiety, which is important during dieting.

Optimization of Conditions of Concentrating Protein in Rapeseed Meal by Ultrasonic-assisted Alcohol Washing

This study was performed to optimize the conditions for concentrating protein in commercial rapeseed meal by ultrasonic-assisted alcohol washing method. The effects of sonication time,particle size,ultrasonic power and liquid to solid ratio on protein content were investigated. The result showed that the optimal conditions for concentrating protein in rapeseed meal were: sonication time of 40 min,particle size of 40 mesh,ultrasonic power of 800 W and liquid to solid ratio of 9∶ 1. Under these conditions,the protein content in rapeseed meal was increased to 55. 47%,which was 10. 43% higher than that in rapeseed meal not treated by sonication.

Amino acid fortified diets for weanling pigs replacing fish meal and whey protein concentrate:Effects on growth,immune status,and gut health

Background： Limited availability of fish meal and whey protein concentrate increases overall feed costs. Availability of increased number of supplemental amino acids including Lys, Met, Thr, Trp, Val, and lie allows replacing expensive protein supplements to reduce feed costs. This study was to evaluate the effect of replacing fish meal and/or whey protein concentrate in nursery diets with 6 supplemental amino acids on growth performance and gut health of post-weaning pigs. Treatments were 1） FM-WPC： diet with fish meal （FM） and whey protein concentrate （WPC）; 2） FM-AA： diet with FM and crystalline amino acids （L-Lys, L-Thr, L-Trp, DL-Met, L-Val, and L-lie）; 3） WPC-AA： diet with WPC and crystalline amino acid; and 4） AA： diet with crystalline amino acid. Results： Pigs in FM-AA, WPC-AA, and AA had greater （P 〈 0.0.5） ADG and gain：feed than pigs in FM-WPC during wk ] （phase 1）. Plasma insulin concentration of pigs in AA tended to be greater （P = 0.064） than that of FM-WPC at the end of wk 1 （phase 1）. Plasma concentrations of IgG in AA was lower （P 〈 0.05） compared with WPC-AA and FW, and FM-AA had lower （P 〈 0.05） IgG concentration than WPC-AA at the end of wk 1 （phase 1）. Concentration of acetate in cecum digesta in FM-AA tended to be greater （P = 0.054） than that of FM-WPC and WPC-AA. Concentration of isovalerate in cecum digesta of pigs in FM-AA was greater （P 〈 0.05） than that of FW and WPC-AA. Conclusions： This study indicates that use of 6 supplemental amino acids can replace fish meal and/or whey protein concentrate without adverse effects on growth performance, immune status, and gut health of pigs at d 21 to 49 of age. Positive response with the use of 6 supplemental amino acids in growth during the first week of post-weaning may due to increased plasma insulin potentially improving uptake of nutrients for protein synthesis and energy utilization. The replacement of fish meal and/or whey protein concentrate with 6 supplemental amino acids could decrease the crude protein level in nursery diets, and potentially lead to substantial cost savings in expensive nursery diets.

Effect of Rice Bran Quality and Protein Supplement, Base Mix, and/or Soybean Meal on Growing Pig Performance in Cambodia

The objective of this study was to evaluate the effect of rice bran quality and dietary supplement source on growing pig performance. A total of 60 castrated male pigs (Yorkshire × Duroc, initially 16.1 kg) were used for 52-day trial. Pigs were allotted to pens in a completely randomized design (4 pigs per pen) and assigned to four dietary treatments in a 2 × 2 factorial with factors being rice bran source (high or low-quality) and source of protein, vitamins, and minerals (supplement or soybean meal and base mix). Analyzed protein and fat level for the high- and low-quality rice bran was 11.07% and 5.86% and 11.20% and 4.50%, respectively. Crude fiber content for high- and low-quality rice bran was 13.44% and 27.79%. Diets were formulated in two phases (phase 1: 16 to 27 and phase 2: 27 to 48 kg) to adjust to the pig’s nutrient requirements. There was no evidence for an interaction (P > 0.05) between rice bran quality × supplement type or main effect of supplement type (soybean meal + base mix vs protein supplement) for final body weight, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G). However, pigs fed high-quality rice bran had improved (P < 0.001) ADG and F/G and lower ADFI compared to pigs fed low protein rice bran. In conclusion, rice bran quality as measured by protein, crude fiber, and fat influenced growing pig performance, while the type of dietary protein supplement did not. Additionally, rice bran with high protein, fat, and low fiber improved ADG and F/G.

超声辅助酶法提取玉米胚芽粕水解蛋白及其抗氧化活性

以玉米胚芽粕为原料,研究超声波辅助碱性蛋白酶提取玉米胚芽粕水解蛋白的工艺条件。通过单因素试验初步确定超声波辅助酶法提取玉米胚芽粕水解蛋白的条件,在单因素试验基础上进行正交试验设计,并测定其抗氧化活性。结果表明,最优提取条件为超声温度50℃、超声时间50 min、超声功率140 W,在此条件下,玉米胚芽粕的水解蛋白提取率为90.6%。对DPPH自由基和羟自由基的IC_(50)分别为17.56µg/mL和28.41µg/mL。

大口黑鲈饲料营养需求及鱼粉替代研究进展

水产养殖动物的精准营养需求参数对其配合饲料的优化或者开发至关重要。文章概述了大口黑鲈蛋白质、脂肪、矿物质、碳水化合物以及维生素等主要元素需求以及蛋白源替代研究,对大口黑鲈饲料配制和降低成本等有重要的指导意义。

低豆粕、低蛋白水平日粮对尼古拉火鸡生长性能的影响研究

试验旨在探究低豆粕、低蛋白日粮对尼古拉火鸡生长性能的影响。选择1日龄尼古拉火鸡360只,结合体型、性别比例随机分为9组,每组设4个重复,每个重复10只鸡。实验分为0~4周龄以及5~8周龄两个阶段,并使用3×3双因素试验方法,研究常规蛋白质水平日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)、蛋白质水平由27%降至25%日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)、蛋白质水平由27%降至23%日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)对尼古拉火鸡生长性能的影响。结果显示,与常规蛋白质水平、玉米-豆粕型日粮组相比,降低4个百分点蛋白质水平日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)火鸡全期增重显著降低(P<0.05),但料重比显著增高(P<0.05),饲料利用率较差。研究表明,尼古拉火鸡日粮的蛋白质水平在0~4周龄阶段由27%降低到25%,5~8周龄阶段由25%降低至23%,火鸡的增重及饲料报酬未受到显著影响,但进一步降低日粮蛋白质水平将会导致火鸡生长性能显著下降。

低蛋白质低豆粕多元化饲粮是养猪节粮增效的关键技术

通过补充适宜种类和数量的工业合成晶体氨基酸,低蛋白质饲粮可以精准满足猪快速生长所需的氨基酸营养需求,避免蛋白质饲料浪费及减少粪、尿氮排放。低蛋白质低豆粕多元化饲粮是以低蛋白质饲粮生产技术为基础,依据各种能量饲料和蛋白质饲料的可利用养分等,配制的原料种类多、养分互补性强、营养平衡度高的低豆粕饲粮。低蛋白质低豆粕多元化饲粮可有效增强猪对饲粮中营养物质的消化、吸收和沉积,降低饲粮中豆粕、玉米等原料的用量,对节粮增效及提高养猪效率具有重要意义。本文从研究与应用进展、对生猪养殖效率的影响、合成氨基酸与天然氨基酸效率对比、氨基酸数量需求情况及产能等方面分析,综述了猪低蛋白质低豆粕多元化饲粮技术、应用效果及前景,以期为相关研究及应用工作提供一定的参考和帮助。

改进鱼类营养和饲料研究范式:从大口黑鲈和大黄鱼配合饲料在养殖生产中的应用谈起

鱼类营养和饲料研究起始于20世纪50年代,并借鉴对人类和畜、禽营养研究的经验建立了研究范式。在过去70年中,鱼类营养和饲料研究遵循已有的范式取得了大量的成果,这些研究成果推动了水产配合饲料技术的进步,为水产饲料产业从无到有、从小到大做出了贡献。然而,随着全球水产养殖规模的不断扩大,水产养殖产业面临的资源和环境压力日益增加,对水产饲料也提出了更多和更高的要求。养殖生产实践表明,根据一些肉食性鱼类营养和饲料研究结果设计配方生产的饲料不能取得预期的应用效果,这意味着遵循已有研究范式所得到的结果难以完全满足现代鱼类养殖生产的需要。本文总结了两种具有重要经济价值的肉食性鱼类(大口黑鲈和大黄鱼)配合饲料在养殖生产中应用的曲折历程,指出早期研究明显低估了饲料蛋白水平是导致配合饲料长期无法在养殖生产中成功应用的主要原因。早期研究报道大口黑鲈的饲料蛋白需求为400~440 g/kg,大黄鱼的饲料蛋白需求为450~470 g/kg,但投喂配合饲料的鱼的生长明显比投喂冰鲜鱼的鱼慢。重新评估发现大口黑鲈和大黄鱼饲料蛋白需求分别为480~510 g/kg和490~520 g/kg,投喂含适量蛋白的配合饲料时鱼生长与投喂冰鲜鱼时接近。对大口黑鲈和大黄鱼饲料蛋白需求的明显低估反映出已有鱼类营养和饲料研究范式中存在不足,其表现为:①强调食物对鱼类生长的影响,但忽视了鱼类遗传背景和食物外的其他环境条件对鱼类生长和摄食的作用;②强调鱼类个体生长可反映其营养需求和饲料质量,但忽视了鱼类个体生长并不能完全反映养殖产量和效益;③强调生长和饲料利用效率在评价水产养殖效益方面的重要性,但忽视了投饵养殖对自然资源和环境所产生的负面影响是限制水产养殖可持续发展的瓶颈;④基础饲料配方对评价营养需求或饲料质量的影响没有得到足够重视,因基础饲料组成不合理导致一些研究结果缺乏实际意义。针对上述问题,作者建议对已有范式的概念、理论和研究方法做如下改进:①重视鱼类遗传背景和食物以外的其它环境条件对鱼类生长的影响,明确鱼类生长潜力决定营养需求,而食物营养是实现生长潜力的条件;②重视食物中各种营养素之间的相互作用,明确不同饲料原料在配方的营养平衡中发挥不同的作用;③进行饲养实验时重视实验鱼种质和种群结构,重视对照组和处理组个体生长的差异幅度在判断处理效应方面的指示意义,重视饲料配方对自然资源和环境等制约水产养殖可持续发展的因素的影响。改进后的研究范式更符合现代水产养殖生产实际,遵循其开展研究获得的结果能够更好地指导饲料配方设计,所生产的配合饲料也能更好地应用于水产养殖生产。

pH循环法从玉米蛋白粉制备蛋白纳米颗粒的研究及其表征

采用pH循环法直接从玉米蛋白粉(CGM)制备蛋白纳米颗粒(CNPs),对其制备工艺进行了优化,对其性质进行了表征,并与利用玉米醇溶蛋白在相同条件下制备的纳米颗粒(ZNPs)进行了比较。结果表明,利用pH循环法可以成功从CGM中制备CNPs,且其最优条件为碱溶pH 13.0、碱溶温度60℃、碱提料液比1∶25、回调pH 7.0,在此条件下CNPs的得率相对于CGM中的蛋白质质量分数达到了69.20%。与ZNPs相比,CNPs具有相近的粒径(282.37 nm)且也携带负电荷,但是原子力显微镜观察结果表明其聚集程度更低;CNPs的疏水性氨基酸质量分数稍低(50.05%),但是α-螺旋和无规则卷曲的含量稍高。另外,CNPs的持水力和润湿性均显著优于ZNPs,且其接触角仅为45.5°,并表现出了更好的Pickering乳液稳定能力。因此,CGM可取代玉米醇溶蛋白作为pH循环法制备蛋白纳米颗粒的原料,这一过程工艺简单、成本较低,对于丰富CGM的综合利用途径、推动玉米蛋白纳米颗粒在食品工业中的应用具有重要意义。

菜籽粕的营养价值及其在猪生产中的应用研究进展

开发与利用非常规蛋白质饲料资源用于减量替代生猪饲粮中的豆粕是当下生猪产业中的重点和难点。菜籽粕是油菜籽榨油后的副产品,是世界上第二大类植物性蛋白质饲料资源,具有粗蛋白质含量高、氨基酸均衡、产量高和成本低等优点,其作为蛋白质原料替代猪饲粮中的豆粕具有广阔的应用前景。但是,因菜籽粕抗营养因子的存在限制了其在猪饲粮中的应用。本文介绍了菜籽粕的营养价值,并阐述了提高菜籽粕饲用价值的生物学方法及其在猪生产中的应用研究进展,以期为生猪饲粮中豆粕减量替代提供参考。

超声波、微波预处理对核桃粕蛋白肽钙螯合能力、结构及稳定性的影响

本研究基于超声波、微波预处理核桃粕蛋白肽及CaCl_(2)的混合物制备核桃粕蛋白肽钙螯合物。分析不同处理对核桃粕蛋白肽钙螯合率、结构变化及稳定性的影响。结果表明,相较未处理的核桃粕蛋白肽钙螯合物(WPP-Ca),超声波处理核桃粕蛋白肽钙螯合物(UP-WPP-Ca)和微波处理核桃粕蛋白肽钙螯合物(MP-WPP-Ca)的螯合率均有所提升,超声波和微波处理有效提高了肽钙螯合能力。基于紫外-可见吸收光谱、傅里叶变换红外光谱分析,发现超声波、微波主要是影响了核桃粕蛋白肽的氨基、羰基、羧基、酰胺键及羧酸盐基团等钙离子结合位点;X射线衍射结果表明超声波、微波处理改变了核桃粕蛋白肽的分子排列进而使核桃粕蛋白肽钙螯合物的结构更有序;荧光光谱结果表明超声波、微波处理促进了芳香族氨基酸与钙离子的螯合。此外,UP-WPP-Ca和MP-WPP-Ca在不同pH值、温度和胃肠道消化中表现出良好的稳定性。总之,超声波、微波预处理后进行的核桃粕蛋白肽钙螯合反应可提高其钙离子螯合能力和稳定性,结果对核桃粕蛋白肽钙螯合物的加工生产及补钙产品的开发具有一定的指导意义。

豆粕陈化对大豆蛋白结构性质及腐竹制备的影响

旨在为低变性豆粕制备腐竹提供参考,分析了豆粕陈化对豆粕中蛋白质结构性质(溶解度、粒径分布、蛋白质组成)和氧化程度(巯基含量、表面疏水性、羰基含量)的影响。同时,以新鲜豆粕和陈化豆粕为原料制备腐竹,考察豆粕陈化对腐竹制备(产率、基本成分、机械性质、颜色、耐煮性)的影响。结果表明:豆粕中的蛋白质在长时间储藏过程(相对湿度40%~50%,温度16℃,储藏时间150 d)中发生疏水聚集导致其溶解度降低,粒径增大和蛋白质组成改变,同时蛋白质氧化导致其游离巯基含量下降,降低了豆粕中蛋白质的共价结合能力;新鲜豆粕制备的腐竹在产率和蛋白质利用率上显著高于陈化豆粕,同时在机械性质、亮度和耐煮性上也显著优于陈化豆粕。综上,豆粕陈化导致豆粕中蛋白质的成膜能力下降,不利于制备高产率和良好品质的腐竹。

棉籽蛋白替代鱼粉对斑点叉尾鮰生长性能、饲料利用和肠道组织结构的影响

试验旨在研究棉籽蛋白替代鱼粉对斑点叉尾鮰生长性能、饲料利用率和肠道组织结构的影响。设计鱼粉含量为100 g/kg的基础饲料,用棉籽蛋白分别替代基础饲料中0、20%、40%、60%、80%和100%的鱼粉配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(171±1)g的斑点叉尾鮰67 d。结果表明:与D1组相比,D5组和D6组的末均重和增重率显著降低,饲料系数显著增加(P<0.05);D3组、D5组和D6组的肝体比显著低于D1组(P<0.05);D6组肌肉粗蛋白含量显著高于D1组(P<0.05);各组斑点叉尾鮰存活率、肥满度、脏体比和肌肉的水分、粗脂肪和粗灰分含量均无显著差异(P>0.05);当棉籽蛋白100%替代鱼粉比例时,饲料的干物质表观消化率和蛋白质表观消化率显著下降(P<0.05),各组之间的脂肪表观消化率无显著差异(P>0.05);在肠道组织学中,棉籽蛋白替代鱼粉对肠道的绒毛高度和肌层厚度无显著差异(P>0.05)。综上所述,在鱼粉含量为100 g/kg的基础饲料中,棉籽蛋白可以有效替代60%的鱼粉不会影响斑点叉尾鮰的生长性能、饲料利用和肠道组织结构。

弱电场中油菜籽蛋白提取优化及结构测定

以冷榨油菜籽为原料,将弱电场引入到油菜籽蛋白的提取中,使用单因素和正交试验结合法对弱电场中油菜籽蛋白提取工艺进行优化。结果表明:油菜籽蛋白提取因素对提取率影响的主次顺序为电压>温度>料液比,最佳提取工艺为电场电压15 V、水污温度30℃、料液比1∶10(g/mL),在此条件下提取率可达7.59%。使用红外光谱及元素分析对产品进行分析,显示提取产物中存在明显的酰胺Ⅰ、Ⅱ、Ⅲ带,其蛋白纯度为88.75%;最后测定了最佳条件提取产物的扫描电镜,结果显示蛋白质成不规则颗粒状。本研究结果证明使用电场絮凝,可获得纯度较高的蛋白质,此研究可为其他种类蛋白质在弱电场中的提取提供一定的参考。

酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰生长性能和肠道健康的影响

试验研究了酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰(Ictalurus punctatus)生长性能和肠道健康的影响。设计鱼粉含量为10%的基础饲料,用酶解棉籽蛋白分别替代基础饲料中33.3%、66.6%和100%的鱼粉,并在100%替代组的基础上添加0.5 g/kg和1 g/kg的单宁酸,配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(172.6±1.6)g的斑点叉尾鮰67 d。结果表明:D4、D5和D6组的末体重和增重率较D1组显著下降(P<0.05),D4和D6组的饵料系数较D1组显著增加(P<0.05)。各组斑点叉尾鮰存活率、肥满度、肝体比、脏体比和肌肉常规成分组成均无显著差异(P>0.05)。斑点叉尾鮰后肠肠道微生物群落的优势菌群包括厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)、变形菌门(Proteobacteria)和梭杆菌门(Fusobacteria)。对比不同处理组发现,D4组的拟杆菌门相对丰度显著低于D5组(P<0.05),D4组的变形菌门相对丰度显著高于D1、D2和D5组(P<0.05)。各组斑点叉尾鮰肠道的组织结构和微生物多样性无显著差异(P>0.05)。综上所述,在鱼粉含量为10%的基础饲料中,酶解棉籽蛋白可以有效替代66.6%的鱼粉而不会对斑点叉尾鮰的生长性能和肠道健康产生负面影响,0.5 g/kg单宁酸能有效改善无鱼粉组斑点叉尾鮰的肠道微生物群落组成,但对生长性能没有提升效果。