不同开口饲料及投喂频率对拉萨裂腹鱼仔鱼存活和生长的影响

为探究不同开口饲料及不同投喂频率对拉萨裂腹鱼(Schizothorax waltoni)仔鱼存活和生长的影响,在水温11℃～12℃,溶氧6.5～7.8 mg/L条件下,选择平均全长14.45 mm仔鱼,设定螺旋藻粉、冰冻轮虫、斑点叉尾鮰饲料、微粒子饲料、草鱼饲料和丰年虫6种开口饲料投喂,再以微粒子饲料投喂,设定6种投喂频率,分别为每2 h、4 h、6 h、8 h、12 h、24 h投喂一次,试验时间42 d。结果显示:冰冻轮虫组存活率显著最低,微粒子饲料组显著最高(P0.05);投喂频率2 h组存活率显著最低,24 h组显著最高(P0.05)。微粒子饲料组的全长生长速度最高,与斑点叉尾鮰饲料组和草鱼饲料组差异不显著(P0.05),但显著高于其他各组(P0.05);投喂频率12 h组和24 h组生长速度显著高于其他各组(P0.05),该两组间无显著差异,其他各组间无显著差异(P0.05)。综合存活率和生长情况考虑,建议在拉萨裂腹鱼仔鱼早期规模化养殖过程中选择微粒子开口饲料,投喂频率为24 h投喂1次效果较好。     

投喂频率对斑点叉尾鮰幼鱼生长、饲料利用和鱼体组成的影响

通过8周的生长试验,研究斑点叉尾鮰(Ictalurus punctatus)幼鱼(初始体重约4.5 g)的最适投喂频率。试验饲料为自制配合饲料,粗蛋白38%,总能19.0 kJ/g。设计了1～5次/d(M1-M5)5种投喂频率。结果表明:M2、M3、M4组摄食率均显著高于M1和M5组(P<0.05),其中M4组最大。M3、M4、M5组的特定生长率均显著高于M1组(P<0.05),其中M3组最大。M2、M3、M4、M5组的干物质表观消化率均显著高于M1组(P<0.05),M3和M4组的蛋白和能量表观消化率均显著高于M1和M2组(P<0.05)。M3组干物质含量显著高于M1和M2组(P<0.05),M2、M3、M4和M5组的粗蛋白、粗脂肪和能量含量均显著高于M1组(P<0.05)。因此,本研究建议,斑点叉尾鮰幼鱼养殖的最适投喂频率为3次/d。     

甘露寡糖对斑点叉尾鮰成活率及生长的影响

在水库中选用8个网箱进行斑点叉尾鮰的养殖试验,网箱分为试验箱和对照箱2个组,每组设4个平行.在试验组的斑点叉尾鮰饲料中添加甘露寡糖进行投喂,甘露寡糖添加量为鱼体重的0.15‰,对照组不添加,试验时间60 d.结果表明,试验组斑点叉尾鮰成活率为94.51%,对照组为87.01%,高出7.5个百分点.随着投喂时间的延长,试验组斑点叉尾鮰的死亡率呈明显下降趋势,至试验结束时的第55～60天,死亡率比对照组的同一时间段下降了10倍;试验组斑点叉尾鮰体重的增加比对照组快16.5%,差异极显著(P<0.01).     

池塘内循环流水养殖斑点叉尾鮰肌肉品质的分析

为探讨池塘内循环流水养殖(IPA)与常规池塘养殖(TPA)的斑点叉尾鮰(Ictalurus punctatus)肌肉品质差异, 测定两种养殖模式下斑点叉尾鮰 3 个不同部位肌肉(背部、腹部和尾部)的营养成分, 同时分析斑点叉尾鮰背部肌肉的质构和肌纤维特性。结果显示: IPA 组尾部肌肉粗蛋白含量显著高于 TPA 组(P<0.05), IPA 组背部和尾部肌肉粗脂肪含量显著低于 TPA 组(P<0.05)。背部肌肉中氨基酸总量、必需氨基酸总量和鲜味氨基酸总量 IPA 组显著高于 TPA 组(P<0.05); 腹部肌肉中的必需氨基酸总量和鲜味氨基酸总量 IPA 组显著高于 TPA 组(P<0.05)。17 种检出脂肪酸中, IPA 组背部、腹部和尾部肌肉中豆蔻酸的含量显著低于 TPA 组(P<0.05), 而二十碳五烯酸(EPA)的含量显著高于 TPA 组(P<0.05); 在背部和腹部肌肉中 PUFA 的总量存在显著差异, 均为 IPA 组高于 TPA 组(P<0.05)。肌肉质构特性方面, IPA 组斑点叉尾鮰肌肉的硬度、弹性、咀嚼性和回复性显著高于 TPA 组(P<0.05); IPA 组斑点叉尾鮰肌纤维直径小、密度高。结果表明, 池塘内循环流水养殖斑点叉尾鮰肌肉品质与营养更具优势。     

喹烯酮对建鲤和斑点叉尾鮰生长性能和抗缺氧能力的影响

在池塘养殖条件下,饲料中添加3个不同含量(50、75和100 mg/kg)的喹烯酮来饲养建鲤(Cyprinus carpio var.Jian)和斑点叉尾鮰(Ietalurus Punetaus),养殖周期为60 d,研究喹烯酮对建鲤和斑点叉尾鮰生长性能和抗缺氧能力的影响。结果表明:与不添加喹烯酮的对照组相比,添加喹烯酮的实验组中建鲤和斑点叉尾鮰生长速度加快,死亡率降低,饲料系数下降。当饲料中添加喹烯酮的剂量为75 mg/kg时,其对建鲤和斑点叉尾鮰的生长效率提高最佳(P0.05),饲料系数最低,成活率最高。在75 mg/kg的喹烯酮添加量下,建鲤和斑点叉尾鮰的抗缺氧能力、血细胞和血红蛋白量均有提高,但与对照组相比,差异均不显著(P0.05)。饲料中添加喹烯酮对建鲤和斑点叉尾鮰生长性能的作用呈现非剂量依赖性,而且添加75 mg/kg喹烯酮对其抗缺氧能力影响不显著(P0.05)。研究表明,建鲤和斑点叉尾鮰养殖中喹烯酮的最适用量为75 mg/kg。     

渔用膨化饲料池塘投喂试验

本文介绍了在池塘中使用浮性膨化饲料养殖斑点叉尾鲴、虹鳟鱼、鲫鱼、胭脂鱼、南美白对虾的试验。结果表明，与投喂传统颗粒饲料相比，使用膨化饲料养殖时鱼类的生长指标和生产效益都具有明显优势。     

酵母免疫多糖对受免斑点叉尾(鮰)免疫应答的增强作用

在饲料中添加定量的酵母免疫多糖,投喂注射接种了福尔马林灭活的嗜水气单胞菌(Aeromonas hydrophila)菌苗的斑点叉尾(鮰)(Ictalurus punctatus),28 d后通过测定供试鱼的增重量、血清中凝集抗体效价、溶菌酶活性、谷丙转氨酶活性(SGPT)、血清总蛋白含量、白细胞吞噬活性以及活菌攻毒后的免疫保护率(RPS),探讨了酵母免疫多糖对受免斑点叉尾(鮰) 免疫应答的增强作用.结果表明,用添加200.0 mg/(kg·d)酵母免疫多糖的饲料投喂受免斑点叉尾(鮰),不仅可以使受免斑点叉尾(鮰) 对灭活嗜水气单胞菌的免疫应答水平提高,增强抵抗嗜水气单胞菌人工感染的能力,而且还具有一定的促进生长和改善肝功能的作用.     

穿心莲对斑点叉尾鮰消化酶活性的影响

为研究穿心莲(Andrographis paniculata)对斑点叉尾鮰(Ictalurus punctatus)消化酶活性的影响,试验选取平均体重为(5.92±0.63)g的健康斑点叉尾鮰270尾,随机分成9组(G0、G1、G2、G3、G4、G5、G6、G7、G8组),每组设3个重复,每个重复10尾鱼,每组分别投喂...     

一例变质饲料诱发红鮰大量死亡的调查与分析

<正>红鮰是斑点叉尾鮰变异品种。2014年6-8月份,位于大通湖边的一口20亩池塘,体重为0.5~1千克的红鮰出现间歇性死亡,虽多次用药但一直未见明显效果,到了8月11日,出现大量死亡;停食后,死亡逐日减少,到8月15日死亡才基本停止。一、红鮰死亡的发生、发展及治疗过程本案例中的池塘为标准化水泥护坡池塘。5月27日投放规格为350~450克/尾的红鮰6765千克,约16900尾。5月30日开始投喂膨化配合饲料。6月3日开始投喂药饵(投喂前,在膨化料中加入硫酸新     

投喂频率对长鳍篮子鱼幼鱼生长性能、肌肉粗营养及血清生化指标的影响

为探究不同投喂频率对长鳍篮子鱼(Siganus canaliculatus)幼鱼生长及生理的影响,分别设置4个投喂频率(1次·d~(-1)、2次·d~(-1)、3次·d~(-1)、4次·d~(-1)),依次标记为F1、F2、F3、F4组,每组设置3个平行,在微流水养殖桶(有效容积125 L)中养殖16周。结果显示:1)生长指标:各组长鳍篮子鱼幼鱼体质量及体长随养殖时间增加均呈线性上升趋势,F3与F4组生长趋势相近;饵料系数和摄食率F3组均为最高,且显著高于F1组(P0.05);F4组肝体比显著高于F1组(P0.05),F1组肠体比与肠长比显著高于F4组(P0.05),F3、F4组肥满度显著高于F1、F2组(P0.05)。2)肌肉粗营养:F1组肌肉中水分含量显著高于其他3组(P0.05),而肌肉粗蛋白含量显著低于其余3组(P0.05);F2、F3组肌肉粗灰分含量显著高于F1、F4组(P0.05)。3)血清生化指标:F2、F3组血清总蛋白含量显著高于F1、F4组(P0.05);而F1、F4组血清白蛋白含量显著高于F2、F3组(P0.05);甘油三酯的含量随投喂频率增加显著增加(P0.05);F4组高密度脂蛋白胆固醇含量最高,显著高于F1、F2组(P0.05),且F4组低密度脂蛋白胆固醇含量显著低于其他3组(P0.05);F3组谷草转氨酶活性及谷丙转氨酶活性显著低于其他3组(P0.05)。结果表明,投喂频率在3次·d~(-1)时长鳍篮子鱼幼鱼的生长效益最佳。     

Effects of feed processing and forms of dietary methionine on growth and IGF‐1 expression in Jian carp

In this study, a practical basal diet (control, C) was supplemented with crystal methionine (Met) (CM) or encapsulated Met (EM), and then was pelleted (P) or extruded (E) to form six diets, PC, PCM, PEM, EC, ECM and EEM. The six diets were fed to Jian carp with initial body of 8.6 ± 0.4 g for 8 weeks to evaluate the effects of Met supplementation and feed processing on growth of the fish. In pelleted diets, weight gain (WG) increased and feed conversion ratio (FCR) decreased (P < 0.05) in response to the supplementation of EM, but both WG and FCR were not affected by the supplementation of CM in the pelleted diet, when compared with PC group. In extruded diets, WG of fish fed ECM or EEM diets was higher and FCR was lower (P < 0.05) than those of fish fed EC diet. In the pelleted diets, the highest level of serum free Met was observed at the 1st, 2nd and 3rd h after feeding for PCM, PEM and PC group, respectively, but the three extruded diet groups showed the same peaking time at the 3rd h after feeding. In both pelleted and extruded diets, the supplementation of EM increased the expression of IGF‐1 gene in muscle (P < 0.05) when compared to PC and EC respectively. Results above indicated that the growth of Jian carp can be improved by the supplementation of EM in pelleted diet, or by the supplementation of EM, CM in extruded diet deficient in Met, but not by the supplementation of CM in pelleted diet.     

Effects of feeding frequency on growth,feed efficiency and body composition of juveniles Brazilian sardine,Sardinella brasiliensis (Steindacher 1879)

The Brazilian sardine is the most important fishery resource in Brazil. Their production has declined along the last 30 years due the overfishing, climatic and oceanographic phenomena. This study was carried out to determine the optimal feeding frequency for juvenile Brazilian sardine based on growth, feed efficiency, feed intake and body composition. Six feeding frequencies of one, two, three, four, five and six times a day were evaluated in triplicate tanks for 50 days. Fish with initial mean weight of 3.29 ± 0.56 g were fed daily to apparent satiation. The results showed that fish fed once daily had lower body weight gain, specific growth rate and condition factor (P < 0.05) compared with other treatments. The feed efficiency ratio in fish fed once daily was significantly higher (P < 0.05) than those fed two or more times a day. No significant differences were observed in the coefficient of variation in body weight (P > 0.05) among the treatments. Feed intake was directly proportional to the feeding frequency. Fish fed once daily showed lower hepatosomatic and mesenteric fat indices (P < 0.05) than the other treatments. Neither protein nor ash content of fish were significantly (P > 0.05) affected by feeding frequency. However, the lipid content increased with feeding frequency. The results suggest that the optimal feeding frequency for juvenile Brazilian sardine is at least twice daily.     

Influences of feeding frequency of extruded pellet and moist pellet on growth and body composition of juvenile Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> in suboptimal water temperatures

This study was carried out to investigate the influences of feeding frequency of extruded pellet and moist pellet on growth and body composition of juvenile flounder (initial mean weight 6.3 g) in sub optimal water temperatures. A 2 (diets: extruded pellet and moist pellet)×2 (feeding frequencies: two and three times daily)×2 (water temperatures: 12 and 17°C) factorial design with three replications was used. After 60 days of feeding, the feeding frequency did not significantly affect growth performance of fish. Weight gain, daily feed intake, feed efficiency and protein efficiency ratio were significantly (P<0.05) higher for fish reared at the higher water temperature. At the same water temperature, weight gain, feed efficiency, and protein efficiency ratio were significantly (P<0.05) higher for fish fed the extruded pellet than moist pellet. The results of this study indicate that feeding frequency of two times daily is sufficient for optimal growth of juvenile flounder when reared in suboptimal water temperatures, and an increase in water temperature from 12 to 17°C improved growth and feed efficiency.     

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。     

Comparative growth and yield of channel catfish and channel × blue hybrid catfish fed a full or restricted ration

Growth and yield (kg ha^?1) of the channel catfish (Ictalurus punctatus, Rafinesque, 1818) and the channel × blue hybrid catfish [I. punctatus female ×I. furcatus (Lesueur, 1840) male], which shared the Jubilee strain of channel catfish as the maternal parent, were compared in sixteen 0.1 ha earthen ponds (14 852 fish ha^?1) during the April to November growing season. Each fish genetic group was fed a commercially formulated 32% protein feed daily to apparent satiation or at 80% of the mean daily satiation ration. Net yield and individual weight were higher for channel × blue hybrid catfish compared with channel catfish and for fish fed a full ration compared with a restricted ration. When fed a full ration, the channel × blue hybrid catfish grew faster from May to September than did the purebred channel catfish because the hybrid catfish consumed a greater percentage of its body weight at each feeding. Net yield within each fish genetic group was lower when feed ration was restricted. The per cent reduction in net yield in response to feed restriction was similar for each fish genetic group.     

酵母水解物对凡纳滨对虾生长、消化酶活性和肠道形态的影响

本实验旨在研究饲料中添加酵母水解物对凡纳滨对虾(Litopenaeus vannamei)生长性能、血清生化指标、肝胰腺消化酶活性以及肠道形态的影响。酵母水解物添加量分别为0%、1%、3%和5%,配制4种等氮等脂(42.5%粗蛋白和8.5%粗脂肪)的实验饲料。选取初始体重为(1.86±0.02)g的凡纳滨对虾480尾,随机分为4组,每组4个重复,每个重复30尾,进行为期8周的养殖实验。结果表明饲料中添加5%酵母水解物组的增重率(WGR)、特定生长率(SGR)和蛋白质效率(PER)显著高于对照组(P0.05),而该组饲料系数(FCR)最低(P0.05)。对虾全虾粗蛋白含量随饲料中酵母水解物的增加而呈上升趋势,且5%酵母水解物添加组显著高于对照组(P0.05)。添加5%的酵母水解物显著提高了凡纳滨对虾血清总蛋白(TP)和甘油三酯(TG)含量,降低了谷草转氨酶(AST)和谷丙转氨酶(ALT)的活性(P0.05)。各处理组肝胰腺淀粉酶活性和对照组相比差异不显著(P0.05),但3%酵母水解物添加组的胰蛋白酶和脂肪酶活性显著高于对照组(P0.05)。3%酵母水解物添加组的对虾肠道皱襞高度和皱襞宽度显著高于对照组(P0.05),而5%添加组的微绒毛高度显著高于对照组(P0.05)。综上所述,在本实验条件下,饲料中添加3%~5%的酵母水解物能有效改善凡纳滨对虾生长性能、提高饲料利用率、促进消化吸收以及改善肠道形态学指标。     

Costs of Winter Feeding of Channel‐blue (♀ Ictalurus punctatus × ♂ Ictalurus furcatus) Hybrid Catfish

Previous research has shown that winter feeding is beneficial in preventing weight loss and maintaining catfish health. Although several studies suggest the importance of winter feeding of channel catfish, Ictalurus punctatus, less is known about optimal winter feeding strategies for channel‐blue hybrid catfish (♀ Ictalurus punctatus × ♂ Ictalurus furcatus). Three winter feeding treatments (unfed, fed daily, and fed based on temperature‐threshold feeding) were each assigned randomly to four replicate 0.10‐ha earthen ponds. All ponds were stocked with large channel‐blue hybrid catfish (0.96 ± 0.40 kg) at the rate of 3409 kg/ha and fed using a slow‐sink 28% protein pelleted feed. The two feeding treatments showed significantly greater mean weight at harvest, gross yield, and growth rates than the unfed fish after the 113‐d winter trial. Partial budget analysis indicated that additional costs incurred from the additional feed, fuel, and labor costs over the winter in fed treatments offset the additional revenue from daily winter feeding. However, in the temperature‐threshold feeding treatment, additional costs were similar to additional revenues when 10‐yr average prices were used. Results were sensitive to feed prices and spring catfish prices with positive net benefits from winter feeding at fish prices above $1.58/kg and feed prices below $0.286/kg.     

Growth and Feed Conversion of Juvenile Heterobranchus longifilis Fed Live Oreochromis niloticus with or without Artificial Feed

Growth and feed conversion were monitored in triplicate groups of the African catfish Heterobranchus longifilis (mean weight 11 ± 1.8 g) fed small (2.5–5.54 cm) tilapia (Oreochromis niloticus) and artificial feeds at various rates (treatments 1, 2, and 3), and tilapia or artificial feed (treatments 4 and 5, respectively). Artificial feed was a 42% crude protein commercial pellet. Live O. niloticus were fed at a rate of 4 g live tilapia/catfish/day. Pelleted feeding rate was 2%, 1%, 0.5%, and 1% of body weight thrice daily in treatments 1, 2, 3, and 5, respectively. After 70 days, mean weight was 180 ± 9.5 g, 157 ± 15.7 g, 147 ± 2.6 g, 77 ± 10.9 g, and 74 ± 10 g, in treatments 1, 2, 3, 4, and 5, respectively. Treatment significantly affected SGR (% day^?1) (P < 0.03) and pelleted feed conversion ratio (P < 0.0003). FCR was 1.09 ± 0.01, 0.63 ± 0.08, 0.42 ± 0.11, and 1.12 ± 0.13 in treatments 1, 2, 3, and 5, respectively. Profit was highest (P < 0.01) in treatment 2. Tilapia consumption seems to improve utilization of artificial feed and may be a way for some catfish farmers to save money.     

Growth, Survival, and Body Composition of Cage-Cultured Nile Tilapia Oreochromis niloticus Fed Pelleted and Unpelleted Distillers Grains with Solubles in Polyculture with Freshwater Prawn Macrobrachium rosenbergii

Abstract.— A 12‐wk feeding trial was conducted in cages with juvenile Nile tilapia Oreochromis niloticus to evaluate distillers grains with solubles (DDGS) as a direct feed, the effects of pelleting on its utilization, and the compatibility of caged tilapia and prawns in polyculture. Nine 1.0‐m³ cages were stocked with 200 juvenile (26 ± 0.9 g) tilapia. Cages were suspended in a 0.2‐ha pond stocked with juvenile freshwater prawns Macrobrachium rosenbergii at 40,000/ha. Three replicate cages were randomly assigned to each dietary treatment. In one dietary treatment DDGS was fed as an unpelleted loose grain ration (26% protein). In a second dietary treatment fish were fed DDGS that had been steam‐pelleted (23% protein). Fish in a third dietary treatment were fed a commercial catfish diet (31% protein) for comparison. After 12 wk, individual weight, individual length, and specific growth rate were significantly higher (P < 0.05) and feed conversion ratio was significantly lower (P < 0.05) for fish fed the commercial catfish diet than for fish fed either unpelleted or pelleted DDGS. Specific growth rate was significantly higher (P < 0.05) for fish fed pelleted DDGS than for fish fed unpelleted DDGS. Survival did not differ significantly (P > 0.05) among treatments (>95%). Although growth was increased in fish fed the commercial diet, their cost of production (<0.66/kg gain) was significantly higher (P < 0.05) than in fish fed unpelleted and pelleted DDGS (<0.26/ kg gain and <0.37/kg gain, respectively). The costs of gain in fish fed unpelleted DDGS was significantly lower (P < 0.05) than in fish fed the pelleted DDGS. Prawn production was 1,449 kg/ha and addition of tilapia in polyculture increased total pond productivity approximately 81 %. These data suggest that DDGS provides economical growth in tilapia when fed as a direct feed and that polyculture of tilapia may improve overall pond efficiency in freshwater prawn production ponds, even at temperate latitudes.