鲤配合饲料中必需氨基酸的量对其在鱼体中沉积率的影响

采用２×３单因子有重复试验设计网箱养鲤鱼种，Ａ、Ｂ两种配合饲料中粗蛋白含量分别为１８．１７％和３１．５６％，氨基酸含量为１６．３５％和２９．５６％，必需氨酸（ＥＡＡ）含量为７．３９％和１３．０８％时，试验结果表明：鲤鱼对Ａ、Ｂ两组饲料中ＥＡＡ的平均沉积率分别为４９．９５％和３７．７３％。对除赖氨酸、组氨酸外的所有ＥＡＡ的沉积率因饲料中氨基酸量的不同呈显著性差异（Ｐ＜０．０５）。饲料中某种ＥＡＡ含量     

配合饲料品质对鲤鱼体内必需氨基酸沉积率的影响

采用２×３单因子有重复方法设计网箱饲养鲤鱼种的试验。Ａ、Ｂ两种配合饲料中粗蛋白含量基本相同，分别为１８．１７％和１７．８６％．必需氨基酸（ＥＡＡ）含量也大体相等，分别为７．３９％和７．３１％。Ａ饲料中动物蛋白源为１０％的鱼粉，Ｂ饲料中为５％的羽毛粉＋５％的鱼粉。试验结果表明：鲤鱼体内赖氨酸的沉积率最高，分别达７３．８８％和７９．５７％；组氨酸次之，分别为６０．２２％和６１．２８％。缬氨酸、蛋氨酸、蛋氨酸＋胱氨酸、苯丙氨酸＋酪氨酸的沉积率因配合饲料的品质不同呈显著性差异（Ｐ＜０．０５）。饲料品质越好，必需氨基酸沉积率越高。     

不同饲料蛋白水平对华鲮幼鱼生长的影响

用3种不同蛋白含量（26．1％、38．3％、52．7％）的配合饲料投喂华鲮幼鱼153d，随着饲料蛋白质含量从26．1％上升到52．7％，平均日增重从0．08g／d上升到0．33g／d，3组之间的日增重和体重有显著差异（P〈0．05）；饲料系数从4．82下降为2．18，3组之间的饲料系数有显著差异（P〈0．05）。3种不同蛋白含量（26．1％、38．3％、52．7％）的配合饲料的成本分别为2．53元／kg、3．75元／kg、5．57元／kg；鱼体每kg增重所需饲料成本分别为12．19元、10．39元、12，14元／。初步认为蛋白含量为38．3％的配合饲料更适合华鲮幼鱼的生产需要。     

网箱养鲤中适宜投饲率的研究

１９９２年１９９３两年用粗蛋白含量２２－４２％的４种配合饲料、７种投饲率（３、４、５、６、７、８、９％）进行网箱养鲤时，５、６、７、８、９月的适宜投饲率分别为５－６％、７％、７．５％、６％和５％。在饲料粗蛋白含量为２０－４０％范围内，蛋白含量增减５％，投饲率应相应减增１％。     

鲟鱼的营养需求与仔鱼投饵技术

我国人工养殖的鲟鱼主要是原产于黑龙江的史氏鲟、杂交鲟及引自俄罗斯的优良品种———俄罗斯鲟、闪光鲟和小体鲟。一、鲟鱼的营养要求１．蛋白质许多学者的研究结果表示，不同种类的鲟鱼对饲料中蛋白质的需求比较接近。高首鲟（体重１４５～３００克）的饲料蛋白含量的适宜范围为３６．５％～４０．５％，最高增重率需求为４９．６％，用Bro－kenlinemodel确定，饲料中蛋白质最适含量为４０．５％±１．６％。西伯利亚鲟（体重２２～４７克）饲料蛋白质的最适含量为４０％±２％，最高增重率需求为４９％。史氏鲟仔鲟的饵料中粗蛋白含量以…     

斑节对虾的精氨酸、蛋氨酸、苯丙氨酸、色氨酸的需求量研究

用额外添加必需氨基酸的实验饲料投喂斑节对虾虾苗，研究斑节对虾的精氨酸，蛋氨酸，苯丙氨酸，色氨酸的需求量。添加精氨酸，对虾的增重明显，并且随着添加量的增大，对虾的增重率也变大，但不影响成活率，当精氨酸占饲料中蛋白质含量１０．３８％时，对虾的增重率，成活率都最高，这时饲料的必需氨基酸比率（Ａ／Ｅ）与对虾肌肉必需氨基酸比率相似。添加蛋氨酸后，对虾的增重率，成活率明显升高，烂尾率明显下降至消失，但三个水平     

鳜幼鱼配合饲料最适蛋白质含量初步研究

采用精制饲料蛋白质梯度法，以鱼粉蛋白和酪蛋白为蛋白源，测定鳜幼鱼配合饲料最适蛋白质含量。试验期平均水温２１℃；试验鱼为平均尾重１５９±２２ｇ幼鳜；试验饲料蛋白质含量梯度为０％—４９９％；养殖３０天后采用直线回归和抛物线回归计算初步确定，鳜幼鱼配合饲料蛋白质最适含量为４４７％—４５８％。对饲料蛋白质含量与饲料蛋白质利用率、饲料系数和投饲率的相关关系进行了讨论     

淡水白鲳一年多次繁殖技术

一、亲鱼培育１．亲鱼的越冬培育冬季当水温在２０℃以上时，亲鱼能正常摄食，必须投放饲料，日投饲量为鱼体重的２％～３％。饲料以蛋白质３０％左右的人工颗粒饲料为主，每隔２～３天还喂谷芽和青菜各１次（约占鱼体重的１％左右）。当水温降至１８～２０℃时投喂量可减少到鱼体重的１％左右。水温在１７℃以下时可不喂饲料。越冬期间亲鱼池如水质污浊可在天晴、阳光充足的天气里换一半水或三分之一原池水，若无晴天而水质又污浊，可每亩平均水深１．０米用０．５千克明矾溶水全池泼洒，也可起到一定的净水作用。２．亲鱼产前的强化培育当…     

无沙养中华鳖试验初探

在５０ｍ＾２无沙水泥池内养殖鳖二个月，放养只重４５．５ｇ的幼鳖２００只，自配混合饲料投饲率４％，平均只日增重２ｇ，成活率９９．５％，获纯利２２８０元，投入产出比１：１．５     

不同投饲率对日本黄姑鱼幼鱼生长及鱼体生化成分的影响

采用一种饲料5个投喂水平(鱼体重1.0%、2.0%、3.0%、4.0%、5.0%)在水温26~28℃的条件下对日本黄姑鱼幼鱼(26.85±1.69g)进行了40d生长实验。结果表明:特定生长率和相对增重率随着投饲率的增加呈先上升后平稳的趋势,饲料利用率随着投饲率的升高呈先下降后平稳再下降的趋势;鱼体的水分含量随投饲率的增加而下降,蛋白质和脂肪含量随投饲率的增加而升高,投饲率对灰分无影响。根据最大相对增重率和最大饲料利用率,确定日本黄姑鱼幼鱼适宜投饲率在水温26~28℃时为3.0%。     

Determination of optimal feeding rates for juvenile lake sturgeon (Acipenser fulvescens) fed a formulated dry diet

Two 3‐week growth trials were performed to determine the optimum feeding rate of juvenile lake sturgeon (Acipenser fulvescens) fed with a semi‐purified dry diet (protein, 440 g; lipid, 130 g/kg) at different feeding rates: 5, 10, 20, 30, and 40 g/kg body weight per day (BW/.d‐1), for 36 g‐sized fish; and 2.5, 5, 10, 20, and 30 g/kg BW/.d‐1, for 80 g sized fish. Feeding rates significantly influenced growth performances, feed conversion ratio, wholebody lipid and moisture contents, energy and protein retention, and fasted blood glucose levels (p < 0.05). The ratio of total C/total N measured in whole fish was positively correlated to the feeding rates and the lipid contents of whole fish. Suboptimal feeding significantly depressed growth performance and protein synthesis based on the measurement of RNA/DNA ratio in white muscle. Based on polynomial regression models, an optimal feeding rate to support the maximum growth, protein and energy retention was 34.5, 22 and 27.3 g/kg BW/.d‐1, respectively, for fish sized at 36–72 g; and 29.0, 16.9 and 19.9 g/kg BW/.d‐1, respectively for fish sized at 80–140 g. Results of this study will benefit future research to develop practical feeds to replace frozen live feed and feed management for lake sturgeon.     

饥饿和补偿生长对史氏鲟幼鱼摄食、生长和体成分的影响

报道了饥饿和再投喂对史氏鲟幼鱼摄食、生长以及生化组成的影响.22±2℃条件下,随着饥饿时间延长,幼鱼白肌的RNA/DNA比值不断减小,体重逐渐下降,后者与同期对照组之间存在极显著性差异(P<0.01).饥饿7d,鱼的肝糖原和肌糖原含量显著降低(P<0.05),但随着饥饿时间的延长,肝糖原和肌糖原含量则出现不同程度的回升;脂肪含量和蛋白质含量分别在饥饿14d和21d时下降幅度最大,提示史氏鲟幼鱼动用储存物质的顺序依次是糖原、脂肪和蛋白质.而饥饿过程中鱼体水分和灰分含量则有所上升.恢复投食后,饥饿幼鱼的摄食强度增大,生长加快,其中7d、14d饥饿组幼鱼的RNA/DNA比值达到或接近正常投喂组水平,但21d饥饿组的比值仍明显低于正常投喂组(P<0.05).恢复投食30d后,7d和14d饥饿组幼鱼体重接近对照组(P>0.05),21d饥饿组的终体重未能赶上对照组(P<0.05),这表明史氏鲟幼鱼的补偿生长随饥饿时间不同而异.试验结束时,各处理组鱼体生化组成与正常投喂组没有显著差异(P>0.05).     

黄河鲇幼鱼对饲料蛋白和能量需要的初步研究

以粗蛋白、总能、赖氨酸、非植酸磷为试验因素,各设6个水平,采用均匀设计U6*(64)制成6种配合饲料,饲喂黄河鲇(Silurus lanzhouensis)幼鱼60 d,研究黄河鲇对饲料粗蛋白和能量的需要量。以相对增重率、特定生长率、肌肉RNA/DNA值为指标,采用偏最小二乘法建立二次多项式回归方程,并对方程进行降维分析和优化求解。结果显示:摄食第3组饲料(蛋白质42%,总能19.50 kJ/g)试验鱼相对增重率、特定生长率、肌肉RNA/DNA均获得最大值,分别为84.83%、1.02%、2.98;随着饲料中粗蛋白、总能的增加,鱼体增重率、特定生长率、肌肉RNA/DNA值均呈先上升后下降的趋势。研究表明,黄河鲇幼鱼对饲料粗蛋白的需要量为42.48%～42.96%,对总能的需要量为19.3～19.4 kJ/g。     

Effects of Feed Application Rates on Growth, Survival, and Feed Conversion of Juvenile Snakehead Channa striatus

Growth, survival and feed conversion ratio of juvenile snakehead Channa striatus were evaluated when fed a dry, formulated feed (50% crude protein) at 24 ± 1 C. Six daily feed application rates were used (0%, 5%, 10%, 15%, 20%, and 30%), as a percentage of fish body weight, with three replicates per treatment. After 29 d, final weights were all significantly greater ( P < 0.01) than initial weights, except for the 0% application. Feed applications higher than 5% did not result in increased growth ( P > 0.05). Feed conversion ratio was 0.99 at 5% feed application, and 6.3 at 30% feed application. Fish survival was increased by providing formulated diet, but no further improvement was found when feed applications exceeded 5%. Cannibalism was reduced by providing formulated feed, but it was unavoidable when substantial differences in fish size existed, even when feeding ad libitum . Our results indicate that the optimal feed application rate is close to 5% body weight/d for juvenile snakehead.     

Dietary Protein Level and Feeding Rate for Hybrid Clariid Catfish,Clarias gariepinus X Heterobranchus bidorsalis,in Homestead Tanks

Abstract

A 3 × 3 factorial experiment was designed to determine the effects of protein levels and feeding rate on growth and body composition of hybrid clariid catfish, Clarias gariepinusX Heterobranchus bidorsalis, over 12 weeks experimental period. Hybrid catfish (initial mean weight 12.53±0.35 g) were stocked in three feeding rates (3%, 5%, or 7% body weight/day (bw/day) and three crude protein levels (30%, 35%, or 40%). Each treatment was assigned randomly to three tanks. Final weight was higher for fish fed at 40% than those fed at 30% and 35% CP. There was no significant difference (P >0.05) in fish fed at 3%, 5%, and 7% bw/day. Also, there was no significant interaction between feeding rate and dietary protein level for weight gain, specific growth rate or feed conversion ratio. Weight gain and feed efficiency under feeding rates increased linearly as protein level increased. Dietary protein levels and feeding rate had significant effect on fish survival. Protein levels had a positive linear effect on fish body protein in all the feeding rates. Based on the above results, 40% CP level and 5% bw/day feeding rate are suggested to be optimal for achieving optimum growth rate and body composition.     

Effect of Dietary Protein Concentration and Feeding Rate on Weight Gain,Feed Efficiency,and Body Composition of Pond-Raised Channel Catfish Ictalurus punctatus1

Two experiments were conducted in earthen ponds to evaluate the effect of dietary protein concentration and feeding rate on weight gain, feed efficiency, and body composition of channel catfish. In Experiment 1, two dietary protein concentrations (28% or 32%) and four feeding rates (≤ 90. ≤ 112, ≤ 135 kg/ha per d, or satiation) were used in a factorial arrangement. Channel catfish Ictalurus punctatus fingerlings (average size: 27 g/fish) were stocked into 0.04-ha ponds at a rate of 24,700 fish/ha. Fish were fed once daily at the predetermined maximum feeding rates for 282 d (two growing seasons). In Experiment 2, three dietary protein concentrations (24, 28, or 32%) and two feeding rates (≤ 135 kg/ha per d or satiation) were used. Channel catfish (average size: 373 g/fish) were stocked into 0.04-ha ponds at a rate of 17,300 fish/ha. Fish were fed once daily for 155 d. In both experiments, five ponds were used for each dietary treatment. Results from Experiment 1 showed no differences in total feed fed, feed consumption per fish, weight gain, feed conversion ratio (FCR), or survival between fish fed diets containing 28% and 32% protein diets. As maximum feeding rate increased, total feed fed, feed consumption per fish, and weight gain increased. There were no differences in total feed fed, feed consumption per fish, or weight gain between fish fed at ≤ 135 kg/ha per d and those fed to satiation. Fish fed the 28% protein diet had a lower percentage carcass dressout and higher percentage visceral fat than fish fed the 32% protein diet. Dietary protein concentrations of 28% or 32% had no effect on fillet protein, fat, moisture, and ash. Feeding rate did not affect FCR, survival, percentage carcass dressout, or fillet composition, except fillet fat. As feeding rate increased, percentage visceral fat increased. Fish fed at ≤ 90 kg/ha per d had a lower percentage fillet fat than fish fed at higher feeding rates. In Experiment 2, dietary protein concentration or maximum feeding rate did not affect total feed fed, feed consumption per fish, weight gain, FCR, or survival of channel catfish. Feeding rate had no effect on percentage carcass dressout and visceral fat, or fillet composition. This was due to the similar feed consumption by the fish fed at the two feeding rates. Fish fed the 24% protein diet had lower carcass dressout, higher visceral fat and fillet fat than those fed the 28% or 32% protein diet. Results from the present study indicate that both 28% and 32% protein diets provide satisfactory fish production, dressed yield, and body composition characteristics for pond-raised channel catfish fed a maximum rate of 90 kg/ha per d or ahove.     

Restricted and Satiate Feeding of Two Genetically Isolated Strains of Juvenile Channel Catfish Ictalurus punctatus Reared on 28% and 32% Protein Diets

A 10-wk growth comparison trial of two strains of channel catfish Ictalurus punctatus was conducted in 40 120-L flow-through aquaria using a 2 ± 2 × 2 factorial experiment design. The three factors evaluated were: strain (Norris and NWAC103), dietary protein level (28% and 32%), and feeding rate (restricted and satiate). Average initial weight (× SD) for the Norris strain was 3.0 ± 0.08 g/fish, while that of the NWAC103 strain was 4.7 ± 0.13 g/fish. The feeding rate for the satiated group was adjusted based on feeding observations. The feeding rate for the restricted group was adjusted to about ²/₃ of the satiate level. For both satiate and restricted feeding regimens, the NWAC103 strain consumed more feed than the Norris strain. Fish of Norris strain fed the 32% protein diet consumed more feed than fish fed the 28% protein diet; however, there were no differences in feed consumption in the NWAC103 fish fed the two protein diets. Regardless of feeding rate, the NWAC103 fish gained more weight and converted feed more efficiently than the Norris fish. Fillet composition was not affected by fish strain. Fish fed the 28% protein diet had a lower level of fillet protein than fish fed the 32% protein diet. In fish fed to satiation, a 32% protein diet resulted in a lower fillet fat level than a 28% protein diet, but no differences were observed in fillet fat levels between fish fed the two dietary protein levels for the restricted group. Results from the present study demonstrate that under laboratory conditions, the NWAC103 strain of channel catfish is superior to Norris strain in feed consumption, growth rate, and feed efficiency. Our data also indicate that either a 28% or 32% protein diet can be fed to either strain of channel catfish whether they are fed to satiation or fed a restricted ration with no detrimental effects on growth.     

Assessment of Compensatory Growth in Channel Catfish Ictalurus punctatus R. and Associated Changes in Body Condition indices

A feeding trial was undertaken to evaluate compensatory growth in channel catfish and to chronicle the changes in body condition associated with the imposed feeding strategy. Four 1200-L circular tanks were each stocked with approximately 600 fingerling channel catfish (mean initial weight 32 g). Two tanks represented control fish which were fed to apparent satiation once daily throughout the trial. The two remaining tanks of fish were unfed for 4 wk and subsequently refed daily to apparent satiation for the following 10 wk in order to elicit a compensatory growth response. Fish fed to apparent satiation during the first 4 wk of the trial had a 41% increase in body weight, while the fasted fish decreased in weight by 20%. During the subsequent refeeding period, previously unfed fish were not able to increase growth rates sufficiently to overcome weight loss imposed by the 4-wk feed restriction. However, after 8 wk of refeeding, total increase in body weight of the previously unfed fish was 179 % of initial weight and similar to that of control fish which gained 231 % of initial weight. Hepatosomatic index (HSI) and condition factor decreased rapidly during the fasting period and increased rapidly to control levels during subsequent refeeding. The intraperitoneal fat (1PF) ratio and muscle ratio responded more slowly to feed restriction with IPF ratio decreasing consistently after 2 wk feed restriction. Muscle ratio showed little effect from the 4-wk period of feed deprivation. It appears that not feeding channel catfish fingerlings for 4 wk is too long to induce a compensatory growth response that is optimal for aquaculture; however, HSI may be the index of choice for detecting when refeeding should begin to maximize compensatory growth.     

Draining system and feeding rate during the initial development of Lophiosilurus alexandri (Steindachner, 1877), a carnivorous freshwater fish

This study evaluated the efficiency of the drainage system during the larviculture of Lophiosilurus alexandri. Moreover, we assessed the best feeding rate after feed training for juvenile production. The study was performed in three phases over 87 days. In phase 1 (40 days), larvae were fed live food and posteriorly submitted to feed training in two drainage systems: water drained on the surface (DS), and water drained into a tank column (DI). In the second phase (30 days), using only the DS system juveniles were fed a formulated diet at feeding rates, 2, 4, 6 and 8% of body wet weight. In the third phase (17 days), the fish from the second phase were fed until apparent satiation. At the first phase, the animals in the DS system exhibited greater survival rates and growth. The best feeding rate for daily weight gain, specific growth rate (SGR) and mean body weights were similar: 5.57, 5.13 and 5.68% respectively. In the third phase, an increased SGR was observed in the treatment groups that received lower feeding rates in the second phase (2 and 4%), which could indicate a possible compensatory growth rate.     

Evaluation of alternative pond production systems for raising largemouth bass,Micropterus salmoides

This study evaluated three different pond‐based production systems for raising largemouth bass, Micropterus salmoides, for the food fish market, using nine 0.04‐ha ponds. Treatments included traditional ponds (TP), intensively aerated ponds (IAP), and split‐pond systems (SPS). TP and SPS ponds were aerated at 9.3 kW/ha, while IAP was aerated at 18.6 kW/ha. TP was stocked at 7,500 fish per ha (three replicates per treatment), and the other two production systems (SPS, IAP) were stocked with 12,500 fish per ha. Feed‐habituated advanced fingerlings (128 ± 47.6 g mean individual weight) were cultured for 157 days. Fish were fed a formulated diet (42% protein, 16% lipid) four times a day, feeding with a maximum allowance of 3% of total body weight and readjusted to the initial body weight biweekly. Fish raised in the SPS displayed a significantly lower specific growth rate, lower individual final weight, and lower weight gain, but the biomass gained was significantly higher than TP but not IAP. Final biomass gained was 50% higher in the SPS and IAP than in the TP. Survival rate and feed conversion ratio were not significantly different among treatments and ranged from 71 to 79% and 1.64 to 2.14, respectively.