膨化参数对饲料淀粉糊化度和蛋白质体外消化率的影响

试验采用胃蛋白酶-胰蛋白酶两步法和β-淀粉酶法分别测定饲料蛋白质体外消化率和淀粉糊化度,探讨了膨化工艺参数对二者的影响。结果表明：物料水分含量、喂料速度、螺杆转速和机筒温度的适度增加都使淀粉糊化度、蛋白质体外消化率增大;机筒温度过高反而使蛋白质体外消化率减小。适宜的膨化条件为：调质后水分26%-30%,喂料速度30-60 r/min,螺杆转速150-250 r/min,机筒温度120-135℃。在此条件下,饲料的淀粉糊化度为90%-92%,蛋白质体外消化率为90%-92%。     

膨化工艺加工饲料的营养生化变化

谷物膨化加工工艺已有30多年的历史，它首先应用于食品工业。用这种方式加工鱼饲料，能更有效地利用谷物淀粉和植物蛋白，并具有独特的水生动物喂饲特性。因此，近几年来，美国、日本、西德、台湾在鱼饲料、实验动物饲料加工等方面都已普遍使用。我国大陆是从1978年开始研制的，目前已有27个省市建立了膨化机专业生产厂。上海、浙江、江西、北京、广东等地都已取得了显著的经济收益。     

饲料中不同种类淀粉对草鱼生长的影响

为探讨不同种类淀粉对草鱼生长的影响;选用规格统一、平均初始体重为(8.58±0.07)g的草鱼,随机分成试验A组、试验B组和试验C组,分别饲喂添加小麦淀粉、玉米淀粉和水稻淀粉的配方饲料;记录试验草鱼的始末体重及饲料消耗量;结果显示：试验A组的相对生长率、饲料效率和蛋白质效率显著高于试验B组(P<0.05),极显著的高于试验C组(P<0.01);试验B组的相对生长率、饲料效率和蛋白质效率显著高于试验C组(P<0.05)。     

大口黑鲈饲料中适宜的淀粉源及添加水平

以4种淀粉,蜡质玉米淀粉(L)、高直链玉米淀粉(Z)、小麦淀粉(X)和木薯淀粉(M),分别以5%和10%的添加量配制了8种等氮和等能(CP 48%,GE 18.5 MJ/kg)的饲料(L5、L10、Z5、Z10、X5、X10、M5和M10)。用上述饲料饲养初始体重为(23.46±0.19)g的大口黑鲈45 d,以评定大口黑鲈饲料的适宜淀粉源及添加水平。结果显示,饲料中淀粉的添加水平和淀粉源对大口黑鲈的生长、饲料利用、体组成和非特异性免疫指标均有显著影响。随着同一种淀粉的添加量从5%升至10%,L10、X10和M10组实验鱼的特定生长率和摄食率显著降低,但饲料效率和蛋白质效率显著升高,而Z5和Z10组间的上述指标的差异不显著;L10、X10和M10组的肝体比、脏体比和肝糖原含量均显著升高,但Z5和Z10组间的脏体比差异不显著;全鱼和肝的脂肪含量及肝的蛋白质含量均显著降低;L10组的红细胞数和红细胞压积、Z10组的血清甘油三酯及X10组的红细胞压积和血清甘油三酯水平显著降低;Z10组的血清补体活性显著降低;L5、Z5、X5和M5组的餐后3~12 h的血糖水平各自低于L10、Z10、X10和M10组。不同的淀粉源在相同的添加量的情况下,Z5组的淀粉表观消化率和肝体比显著地低于L5、X5和M5组,而脂肪沉积率显著高于L5、X5和M5组;M5组的蛋白质表观消化率显著低于L5、Z5和X5组;Z10组的淀粉表观消化率、肝体比、脏体比和肝糖原含量显著低于L10、X10和M10组,而脂肪沉积率显著高于L10、X10和M10组;M10组的蛋白质表观消化率显著低于L10、Z10和X10组。饲料中淀粉的添加水平和淀粉源对大口黑鲈的摄食率、特定生长率、蛋白质消化率、脂肪沉积率、肝体比、肝糖原含量、红细胞数、血清甘油三酯含量和血清补体活性均有显著的交互作用。本研究表明,饲料的淀粉源和水平对大口黑鲈的生长、体组成、血液学指标、餐后血糖和非特异性免疫指标均有不同程度的影响,饲料中添加5%的蜡质玉米淀粉、高直链玉米淀粉、小麦淀粉和木薯淀粉均无妨碍,但添加10%的淀粉水平唯有高直链玉米淀粉较为合适。     

膨化工艺参数对饲料含脂量及养殖效果的影响

本文以鲤鱼为研究对象，选未增添油脂的非膨化料和膨化料作系统对照，采用L8（2^4)正交设计研究膨化工艺参数对饲料的含脂量及养殖效果的影响。结果表明：1、膨化后饲料的含脂量降低，调质温度80－95℃、DDC加水19％、UPC加水0％、干燥温度110℃（30分钟干燥时间）的加工工艺对油脂损失最少；2、与非膨化料相比，只超量添加热敏维生素的膨化料养殖效果差，同时增添油脂后可降低饲料系数至非膨化料水平，但养殖成本增高。     

膨化与非膨化饲料对大规格草鱼生长、体成分及部分生理生化指标影响

以商业配方为基础,配制膨化饲料和非膨化饲料饲喂初始体重（394.96±13.21g）草鱼（Ctenopharynodon idellus）120天,旨在对比这两种饲料对其生长、体成分及部分生理生化指标的影响。养殖试验在水库网箱（2m×2m×2m）中进行,每个处理组3个重复,每个重复30尾鱼。实验结果表明,与非膨化料组相比,膨化饲料组草鱼成活率和增重率显著提高（P＜0.05）,饵料系数显著降低（P＜0.05）,增重成本显著降低（P＜0.05）;肥满度、肝体比、脏体比和肠体比显著升高（P＜0.05）;鱼体血清血糖、甘油三酯、总固醇和过氧化氢酶显著升高（P＜0.05）;胰蛋白酶、淀粉酶和脂肪酶显著降低（P＜0.05）;肝脏谷丙转氨酶（GPT）显著升高,谷草转氨酶（GOT）显著降低（P＜0.05）;鱼体成分中水分和灰分无显著差异（P>0.05）,粗脂肪显著升高、粗蛋白显著降低（P＜0.05）。综上所述,与非膨化饲料相比,饲喂膨化饲料可使大规格草鱼生长性能和养殖效益提高,但会鱼体肥满度和粗脂肪含量提高。     

配合饲料中α-淀粉与生淀粉比例对乌龟生长的影响

饲料粗蛋白质量分数39.98%~40.28%,淀粉总量占饲料24%。7组饲料中,α-淀粉质量分数分别为3%、6%、9%、12%、15%、18%、21%,生淀粉质量分数分别为21%、18%、15%、12%、9%、6%、3%。试验龟均重(14.46±1.46)g,试验时间56 d。结果表明,组与组之间相对增重率、饲料系数均有显著差异。相对增重率随着α-淀粉在饲料中的比例增加而增大,当达到一定程度时增重趋缓;饲料系数则随着α-淀粉比例增大而减小。以α-淀粉与生淀粉之比1:1即各占饲料质量分数12%为最适比例。     

饲料不同加工方式对草鱼生产性能的影响

采用同一营养水平的饲料配方,试制了非膨化沉性硬颗粒饲料和膨化浮性颗粒饲料(简称非膨化饲料和膨化饲料)。设非膨化饲料、膨化饲料和膨化与非膨化饲料混合投喂三个处理组(A非膨化饲料组; B膨化饲料组; C非膨化饲料∶膨化饲料=1∶1组)。每个处理三个平行,网箱养殖。结果:三个处理组,增重率、特定生长率、肥满度等均有差异;全鱼营养成分、水分、蛋白质和灰分含量差异不显著;脂肪含量差异显著。结果表明:膨化饲料喂养草鱼生长速度更快,肥满度较大;而非膨化饲料喂养的草鱼脂肪含量更低,肥满度相对较小;混合投喂介于两者之间。因此,草鱼养殖户可根据市场需求选择不同加工方式的饲料投喂。     

膨化沉性饲料和粉状饲料对菊黄东方鲀生长和氮磷收支的影响

为进一步探究膨化沉性饲料在菊黄东方鲀(Takifugu flavidus)养殖中的合理应用,在盐度7~10、水温22.6~29.4℃条件下,于室内水泥池开展了为期62 d的膨化沉性饲料与粉状饲料饲喂菊黄东方鲀的对比试验,比较2种饲料对鱼体生长和养殖系统氮(N)、磷(P)收支的影响。结果表明:(1)2个饲料组鱼的终末体质量、增重率、特定生长率、净产量、成活率、比肠长、肥满度等指标均无显著差异(P0.05);膨化沉性饲料组鱼的肝体比、脏体比显著高于粉状饲料组(P0.05),饲料系数显著低于粉状饲料组(P0.05)。(2)饲料是养殖系统中N、P的主要输入源,分别占总输入的67.7%~72.9%和76.4%~82.6%,其次为水体和养殖生物;养殖试验中膨化沉性饲料组投入的N、P量(51.46、9.64 g/m~2)显著低于粉状饲料组(65.97、14.18 g/m~2)(P0.05)。(3)废水(换水+终末水体)为N、P的主要输出源,分别占输入总量的61.7%~62.8%和45.2%~51.7%,其次为鱼体固定和吸污输出;膨化沉性饲料组经废水输出的P(5.71 g/m~2)和经吸污输出的N、P量(4.18、3.48 g/m~2)均低于粉状饲料组(8.88、6.11、4.50 g/m~2)(P0.05);被鱼体固定的N、P量组间差异不显著(P0.05)。(4)膨化沉性饲料组N、P的利用率分别为18.0%和16.5%,较粉状饲料组分别高42.9%和139.1%;水体N、P负荷量分别为70.55、15.35 kg/t,较粉状饲料组分别低32.9%和44.1%。研究表明,采用膨化沉性饲料饲喂菊黄东方鲀能提高饲料中N、P的利用效率,降低养殖系统的N、P排放。     

Evaluation of different starch sources in extruded feed for Atlantic salmon

The aim of the experiment was to investigate the effect of partial or total substitution of wheat flour with oat meal and tapioca starch in extruded salmon feed. A mixture design (simplex centroid mixture design) was used to analyse the effect of starch source on physical quality of extruded feed. Physical quality of the extruded feed was evaluated as cohesiveness, pellet density, axial and radial expansion, durability, hardness, strain at rupture and elastic modulus. Starch sources affected behaviour of the diet formulations during extrusion and caused changes in the physical properties of the extruded products. Significant correlations (P < 0.05) between physical properties and weight fraction of the starch sources allowed the establishment of predictive models. The inclusion of oat meal and tapioca starch in the diet gave extruded feed with a higher porosity and lower oil absorption capacity. The mechanical properties of the extruded feeds were significantly different from each other, most likely due to the complex nature of texture formation with respect to process parameters and properties of ingredients.     

Pea and wheat starch possess different processing characteristics and affect physical quality and viscosity of extruded feed for Atlantic salmon

The aim of the study was to investigate the effect of starch source, retention time in the preconditioner and screw speed (RPM) on physical quality of extruded fish feeds. The experiment was arranged in a three by two by two factorial design using three carbohydrate sources [wheat starch (WS), pea starch (PS) or a combination (WS_PS)], two retention times in the preconditioner [long (120 s) or short (62 s)] and two RPM in the extruder [high (300) or low (220)]. Physical quality was assessed by hardness, diameter, expansion ratio, Holmen durability (HDI), DORIS value (DV), oil absorption capacity, oil leakage and pasting viscosity. The results showed that retention time in the preconditioner only affected HDI and oil leakage. Long retention time improved HDI but caused a greater leakage. Changing screw speed from 220 to 300 RPM gave a greater expansion ratio, improved HDI and oil absorption. PS resulted in higher pasting viscosity, HDI and DV, but a generally lower hardness than WS. To conclude, PS and WS have different processing characteristics, and the conditions need to be adjusted according to the starch source used when producing extruded fish feed.     

饲料添加剂在水产动物生长、营养及免疫中的应用进展

饲料添加剂是在基础饲料的生产加工或使用过程中添加微量物质,具有强化基础饲料营养价值,节省饲料成本,提高动物生产性能,改善肌肉品质等作用.目前国内外对饲料添加剂的研究众多,为突出饲料添加剂对水产动物在不同方面的影响,本文综述了饲料添加剂对水产动物生长性能、营养成分及免疫中的应用进展.     

Utilization of different raw and pre-gelatinized starch sources by juvenile yellowfin seabream Sparus latus

Raw corn starch (RCS), raw tapioca starch (RTS), raw potato starch (RPS), pre‐gelatinized corn starch (PCS), pre‐gelatinized tapioca starch (PTS) and pre‐gelatinized potato starch (PPS) were evaluated as starch sources in diets for yellowfin seabream Sparus latus in a 56‐day growth trial. Seven isonitrogenous semi‐purified diets comprising a non‐starch cellulose control diet and the six different starch sources holding 200 g kg⁻¹ starch each were prepared and fed to triplicate groups of juvenile yellowfin seabream S. latus. Fish were fed for 8 weeks. Weight gain (WG) and specific growth rate (SGR) for fish fed RCS, RTS and RPS diets were equal, as well as for fish fed PCS, PTS and PPS diets, but values in groups fed the raw starch sources were significantly higher compared with fish fed the pre‐gelatinized starches. Feed efficiency and protein efficiency ratio in fish fed different starch source diets showed no significant differences but were significantly higher than those fed a non‐starch control diet. Protein productive value was improved by starch incorporation to diets. PCS, PTS or PPS groups showed lower feed intake compared with RCS, RTS or RPS groups, and the differences were significant between PCS, PPS and RCS, RPS groups. Whole‐body protein and ash contents and muscle compositions were not affected by different starch sources. Whole‐body and liver lipid contents, liver moisture and glycogen contents were significantly affected by starch source. Values of hepatosomatic index, intraperitoneal fat ratio, viscerosomatic index and condition factor did not vary between experimental treatments. Plasma total protein concentration for RCS, RTS or RPS fed fish was significantly higher than that for PCS, PTS or PPS fed fish, but significantly lower than that for non‐starch fed fish. Plasma cholesterol and triacylglycerol concentrations were unaffected by starch source, but were significantly higher in fish fed the non‐starch control diets. Plasma glucose concentrations in all dietary groups were relatively stable. In conclusion, raw corn, tapioca and potato starches at a 200 g kg⁻¹ inclusion level were well utilized as energy sources by yellowfin seabream, which was evidenced by better WG and SGR. Pre‐gelatinization of the starches had no positive effect on starch utilization.     

鲟营养组成、高值化加工利用及质量安全研究进展

鲟（ Acipenser）是中国冷水水域重要的养殖鱼类,近年来养殖产量逐年增加。由于缺乏全面系统的鲟高值化加工利用技术,中国鲟消费长期以幼鱼鲜食为主。文章详细论述鲟鱼卵、鲟肉的营养与风味特征,阐明鲟高值化加工利用技术、质量安全及原产地鉴别技术现状,对鲟产业发展趋势进行展望,旨在为中国鲟产业的健康发展提供参考。     

不同饲料料型及投喂频率对斑点叉尾鮰幼鱼生长及肌肉品质的影响

本研究旨在探究不同饲料料型及投喂频率对斑点叉尾鮰(Ictalurus punctatus)生长及肌肉品质的影响。研究采用双因素试验设计,以饲料料型(膨化饲料,EF;颗粒饲料,PF)和投喂频率(2次/日,F2;3次/日,F3)为影响因素,共4个组,分别命名为EFF2、PFF2、EFF3和PFF3,每组3个平行,投喂8周,每天定时投喂两次(7:30和16:30)或3次(7:30, 12:00, 16:30)。结果显示,斑点叉尾鮰的末重和增重率受到投喂频率的影响,F2组显著高于F3组(P0.05);而饲料料型则对斑点叉尾鮰的生长无显著影响(P0.05)。颗粒饲料组的肌肉粗脂肪含量和内聚性、回复性显著低于膨化饲料组(P0.05),而硬度显著高于膨化饲料组(P0.05)。F3组的肌肉硬度、胶着性和咀嚼性则显著高于F2组(P0.05)。颗粒饲料组生肌调节因子5 (myogenic factor 5, Myf5)和肌肉生长抑制素(myostatin,MSTN)基因的相对表达量显著低于膨化饲料组(P0.05)。F3组肌肉中MSTN基因相对表达量显著高于F2组,而肌细胞生成素(myogenin,MyoG)基因相对表达量则呈现相反趋势。综上,投喂同种配方的膨化饲料和颗粒饲料对斑点叉尾鮰的生长效果相似,但是投喂颗粒饲料的斑点叉尾鮰硬度更大,而投喂膨化饲料则肌肉脂肪含量更高;斑点叉尾鮰的最佳投喂频率是每天2次。     

A review of the effects of ingredient composition and processing conditions on the physical qualities of extruded high‐energy fish feed as measured by prevailing methods

Feed comprises the biggest cost in intensive fish farming and the quality of feed is therefore important. A vast body of research has been carried out in order to investigate nutritional quality of alternative ingredients. Effects of ingredients on physical quality are seldom included in these investigations. Physical quality of feed varies with ingredient composition and processing condition and may interfere with feed intake, nutrient digestibility and therefore growth performance of the fish. In this review, physical quality of extruded, high energy feed, and how ingredient composition and processing conditions affect the quality will be addressed. Various pellet properties will be discussed and methods used to evaluate physical quality will be reviewed.     

罗非鱼综合加工利用与质量安全控制技术研究进展

经过多年发展,目前中国罗非鱼产业正处于从规模产量型向质量效益型转变的关键时期,对罗非鱼原料进行高值化综合加工利用,同时确保产品的质量安全,是提高中国罗非鱼产业竞争力的必由之路。要实现这一目标必须依靠技术创新来实现产业升级,以保障中国罗非鱼产业可持续稳定发展。文章综述了近年来国内外在罗非鱼综合加工利用与质量安全控制方面的研究进展及发展趋势,旨在为中国罗非鱼产业的健康发展提供参考与借鉴。     

Utilization of different carbohydrate sources and starch forms by bagrid catfish (Mystus nemurus) (Cuv & Val)

Two experiments were conducted to ascertain the utilization of different carbohydrate sources and different forms of starch present in bagrid catfish (Mystus nemurus) fry. The nutritional quality and starch forms of cornstarch, dextrin, broken rice, and sago flour were evaluated in a 4 × 2 factorial design. All diets were formulated to be isonitrogenous (400 g kg^?1 crude protein) and isolipidic (150 g kg^?1 crude lipid), fed to triplicate groups of bagrid catfish fry (initial weight 6.04 ± 0.04 g). Growth studies, enzymatic response and postprandial plasma glucose were observed. A two‐way anova (P > 0.05) analysis of the data obtained showed that the final body weight, specific growth rate (SGR) and food conversion ratio (FCR) were significantly affected by carbohydrate source, but not significantly affected by starch form. Fish fed broken rice and corn starch had similar SGR and FCR compared to fish fed with dextrin and sago flour. The postprandial plasma glucose trend in fish fed with corn starch and broken rice showed a gradual increase while sago flour and dextrin‐fed fish peaked at 2 and 3 h, respectively. Lipogenic enzyme (G6PDH) activity were more pronounced than gluconeogenic enzyme (ME) in M. nemurus irrespective of carbohydrate source and starch form. Therefore, we suggest that raw broken rice and corn starch are suitable carbohydrate sources in the M. nemurus diet.     

微塑料染污及其对不同栖息地、不同食性海洋鱼类影响的研究进展

随着微塑料在海洋环境和海洋生物中的发现,海洋微塑料污染问题越来越受到关注.本文对海洋微塑料的来源、类型、分布规律、毒性以及不同栖息地、不同食性海洋鱼类对微塑料的摄取特性和受到影响进行了梳理,对后续研究方向进行了分析和展望.结果显示,微塑料来源广泛、种类繁多、分布在海洋的各个角落,在海洋中垂直分布特点为底层沉积物含量较高...