耐高温酶制剂对奥尼罗非鱼生长和消化酶活性的影响

在初始体质量(64.35±1.75) g 的奥尼罗非鱼基础饲料中分别添加0、0.05%、0.10%、0.15%的耐高温酶制剂饲喂56 d,探讨耐高温酶制剂对奥尼罗非鱼生长以及消化酶活性的影响.试验结果表明,饲料中添加耐高温酶制剂能促进奥尼罗非鱼的生长,提高质量增长率,降低饵料系数,提高奥尼罗非鱼消化酶活性.当耐高温酶制剂添加量为0.10%时,奥尼罗非鱼的质量增长率、前肠蛋白酶活性和淀粉酶活性以及肝胰脏淀粉酶活性最高,饵料系数最小,与对照组相比差异显著(P＜0.05).     

耐高温酶制剂对鲤鱼生长的影响

目前，池养鲤鱼的主粮为配合饲料，而配合饲料的各种主原料如棉粕、豆粕、鱼粉、米糠等都为熟干品．这些原料在熟态下所含的酶类几乎都被破坏，鲤鱼摄食此种饵料增加了其消化吸收的难度，造成营养不良．生长缓慢，在此情况下只增加营养成分于饲料中。也难以发挥应有的作用。另外，饲料中添加的酶类在饲料加工过程中因温度过高容易失活。     

耐高温酶制剂对奥尼罗非鱼免疫和肠道结构的影响

为了验证耐高温酶制剂的使用效果,试验在基础饲料中添加0.1%的耐高温饲用酶,饲养奥尼罗非鱼60d,测定罗非鱼血清中非特异免疫指标,并电镜观察小肠细胞微绒毛排列情况;同时测定饲料厂制粒前后蛋白酶活力的变化情况。结果表明,添加耐高温酶制剂组超氧化物歧化酶(SOD)和溶菌酶水平比对照组有显著提高(P<0.05);同时,试验组罗非鱼小肠细胞微绒毛排列整齐、细而长,吸收面积增大;对照组的小肠细胞的微绒毛稀疏、短,排列不均匀。结果证实,在罗非鱼饲料中添加耐高温酶可以显著增强其免疫力,增加其对饲料的吸收率。制粒冷却包装后酶活力仍可保持90%以上,而普通酶只有25%左右。     

莫荷罗非鱼肌肉营养成分的分析与评价

对莫荷罗非鱼(Oreochromis mossambicus×Oreochromis hornorum)进行主要营养成分分析,并对其营养价值进行了评价。测定结果表明:莫荷罗非鱼肌肉水分、粗蛋白、粗脂肪、粗灰分含量分别为(72.55±0.04)%、(24.22±0.13)%、(1.70±0.04)%、(1.40±0.02)%;莫荷罗非鱼肌肉中17种氨基酸总量为88.34%(干重),必需氨基酸总量为36.19%,占氨基酸总量的41%,4种风味氨基酸总量为34.52%,占氨基酸总量的39%。以AAS进行评价,莫荷罗非鱼肌肉中第一限制性氨基酸为缬氨酸(Val),第二限制性氨基酸为亮氨酸(Leu)。以CS进行评价,第一限制性氨基酸为蛋氨酸+胱氨酸(Met+Cys),第二限制性氨基酸为为缬氨酸(Val)。其必需氨基酸指数为93.55。实验分析表明,莫荷罗非鱼是一种营养价值较高,具有较好食用价值的鱼类。     

氧化三甲胺对罗非鱼生长和鱼体营养成分组成的影响

在饲料中添加0.2%、0.4%和0.8%的氧化三甲胺饲养罗非鱼,经过60d的生长试验,观察不同添加量的氧化三甲胺对罗非鱼的生长、机体营养成分组成的影响。养殖试验结果表明,添加氧化三甲胺可以促进罗非鱼生长,并对改变罗非鱼内脏的相对重量,提高肥满度有一定作用。尤其0.2%的试验组与对照组相比,末重、日增重和特定生长率均有显著的差异。此外,添加氧化三甲胺可以显著降低罗非鱼肌肉和肝胰脏中的粗脂肪含量。     

饲料中添加甜菜碱对尼罗罗非鱼生长_肌肉组成和消化率的影响

甜菜碱是甜菜加工副产品中提取的甘氨酸甲基内酯,甜菜碱以前仅限于作为动物营养的甲基供体,参与氨基酸的合成和协同作用。作为人类医学上的恢复胃酸的药物及肝脏保护性治疗剂等［朱仲贤１９７９］,参与氨基酸的合成和协同作用。甜菜碱作为鱼类的饲料添加剂的主要作用是...     

吉富罗非鱼与奥利亚罗非鱼完全双列杂交后代生长性能与肌肉营养成分的比较

以吉富罗非鱼(Oreochromis niloticus)与奥利亚罗非鱼(O.aureus)为繁育亲本,采用完全杂交进行配组,分别对吉富罗非鱼奥利亚罗非鱼纯繁与正反交后代生长性能和肌肉营养成分进行了比较,并且研究了脂代谢相关基因mRNA水平与肌肉脂肪含量的相关性。将初始规格基本一致的4组F1罗非鱼饲养100 d后,吉富罗非鱼纯繁组F1特定生长率最高(P0.05),吉富罗非鱼奥利亚正反交组合无显著差异(P0.05),奥利亚纯繁组F1特定生长率最低(P0.05)。同时,奥利亚纯繁组F1的饲料转化率、肝体比与内脏比指数显著高于其他实验组(P0.05)。各实验组水分、灰分与粗蛋白含量间无显著差异(P0.05),吉富纯繁组F1的粗脂肪含量显著高于其他组合(P0.05)。奥利亚纯繁组F1的必需氨基酸、呈味氨基酸与氨基酸总含量均显著低于其他实验组(P0.05),4组F1的肌肉必需氨基酸组成均符合FAO/WHO的标准。吉富纯繁组F1的饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸以及n-6多不饱和脂肪酸含量均显著高于正反交组合与奥利亚纯繁组F1(P0.05)。肌肉FAS、LPL、HSL和G6PD mRNA水平与脂肪含量的相关性分析表明,FAS与G6PD mRNA水平与肌肉脂肪含量呈负相关,相关系数(R2)分别为0.761 5(P0.01)和0.538 7(P0.05);LPL和HSL mRNA水平与肌肉脂肪含量呈正相关,相关系数分别为0.782 5(P0.01)和0.562 4(P0.05)。研究结果表明,奥利亚纯繁组F1的生长与肌肉营养成分明显劣于其他实验组,证明杂交能够提高后代的生长性能,改良肌肉品质,增加选育的综合效果。同时,吉富罗非鱼奥利亚正反交组合间LPL与G6PD mRNA水平间无显著差异(P0.05),增加肌肉脂肪含量有助于提高LPL和HSL mRNA表达水平。     

耐高温酶制剂对草鱼生长的影响

目前．草鱼的主粮为配合饲料，而配合饲料的各种主原料如棉粕、豆粕、鱼粉、米糠等都为熟干品，这些原料在熟态下所含的酶类几乎都被破坏，草鱼摄食此种饵料增加了其消化吸收的难度，造成营养不良，生长缓慢．在此情况下只增加营养成分于饲料中，也发挥不出应有的作用。另外，饲料中添加的酶类在饲料加工过程中因温度过高容易失活(一般酶制剂在80℃左右会失去活性)。耐高温酶是一种由蛋白酶，淀粉酶，纤维素酶等组成的复合酶(由广州市博仕奥生化技术研究有限公司提供)，经特殊处理后在饲料加工过程中其不易被失活．从而有助于鱼的消化吸收，促进生长。     

添加不同构型肉碱对于罗非鱼生长和鱼体营养成分组成的影响

在饲料中分别添加 2 0 0mg·kg-1,40 0mg·kg-1的DL -肉碱和 2 0 0mg·kg-1的L -肉碱 ,饲养初始重为38.6 5± 0 .2 1g的罗非鱼 ,经过 34d的生长试验 ,观察不同添加量的DL -肉碱与L -肉碱对于罗非鱼生长情况、机体营养成分组成的影响。实验结果表明 ,添加两种构型肉碱对于罗非鱼并无促生长作用 ,也未明显改变全鱼和肌肉的营养成分组成 ,但是对于改变罗非鱼内脏相对重量、降低肝脂则有一定作用 ,这些作用和影响在相同添加量 (2 0 0mg·kg-1)的DL -肉碱与L -肉碱之间无显著差异 (P >0 .0 5 )。     

脆化专用饲料对罗非鱼生长和肌肉品质的影响

为考察脆化饲料对罗非鱼(Tilapia)生长和肌肉品质的影响,实验分别以配合饲料(对照组)、脆化饲料(试验组)喂养体质量为(115.30±23.69)g的罗非鱼99d.结果显示:配合饲料组和脆化饲料组罗非鱼的增重率分别为185.25％、94.96％;饲料系数为1.87、2.94;肥满度为15.23、12.50;肌肉粗蛋白含量为19.40％、18.26％;粗脂肪含量为0.75％、1.32％;胶原蛋白为2.03、2.91;肌原纤维耐折力为33.93 μm、64.84 μm;滴水损失为2.59％、1.82％.与对照组相比,在生长方面,脆化饲料组罗非鱼增重率、肥满度显著降低,饲料系数显著增加(P＜0.05);在肌肉品质方面,肌肉的粗蛋白含量和滴水损失显著降低,而粗脂肪含量、胶原蛋白含量和肌原纤维耐折力显著提高(P＜0.05).结果表明,脆化饲料在一定程度上改善了罗非鱼的肌肉品质.     

微生物和中草药联合制剂对罗非鱼生长和水质的影响

采用单因素试验方法,研究微生物和中草药联合制剂对罗非鱼生长的影响。实验分5组,鱼种规格为9.90±0.41 cm,分别投喂基础饲料添加6%的放置8个月的添加剂(A组)、基础饲料添加6%的现配现用的添加剂(B组)、基础饲料添加6%的已稀释到30%的现配现用的添加剂(C组)、基础饲料添加6%的其他公司同类产品(D组)和基础饲料(对照E组),室内饲养30 d。结果表明:联合制剂对罗非鱼的体重和体长的增长有显著影响(P<0.05),并且B组的体重增长率和体长增长率最高,比对照组分别升高119.03%、17.86%,且该组的饲料系数也是最低的,较对照组下降40%;各组的成活率无显著差异(P>0.05)。实验组的氨氮极显著地高于对照组(P<0.01),而亚硝酸氮极显著低于对照组(P<0.01)。实验结果可见,联合制剂能显著促进罗非鱼幼鱼生长,提高饲料的利用,并且B组添加剂的效果最佳;此型联合制剂对氨氮无降低作用,但有较明显的降亚硝酸氮作用。     

饲料成分与环境温度对奥尼罗非鱼消化酶活性的影响

取相同生长阶段、体重均匀的雄性奥尼罗非鱼(Oreochromis nilotieus×O.aureus)为研究对象,分别设置不同P／E饲料组与不同水温组进行暂养,共3周。在最后一次投喂后2 h进行取样测定。结果表明,饵料蛋白质水平在20％-40％时,肝胰脏和肠道蛋白酶活性变化差异不显著。胃蛋白酶活性随着饵料蛋白水平上升而减低了22.2％和26.0％(P<0.05)。碳水化合物水平由34％上升到42％和50％,肝胰脏淀粉酶活性分别上升了107.1％和106.6％(P<0.01),肠道淀粉酶活性分别提高了67.1％和39.8％(P<0.01)。脂肪水平由1.5％升高7％,肠道脂肪酶活性没有变化,脂肪水平升高到12.5％,肠道脂肪酶活性降低了25.4％(P<0.01)。在水温17-32℃时,罗非鱼消化酶活性均随环境温度的升高而提高。     

Effects of pond depth and water temperature on the growth, mortality and body composition of Nile tilapia, Oreochromis niloticus (L.)

The effects of varying water depths and temperature on the growth, feed utilization, mortality rates and body composition of Nile tilapia, Oreochromis niloticus (L.), were evaluated. Triplicate groups of 20 fish (mixed-sex) m^-3 were stocked into 200-m² freshwater earthen ponds maintaining four water depths: 50, 100, 200 and 300 cm. The fish were fed on commercial fish pellets (23% protein), twice a day for 10 months (May 1991-February 1992). Water temperatures ranged from 5 ^oC to 33 ^oC. Growth performance and survival were significantly affected by pond depth and water temperature. Fish weight gain was lowest (250 g per fish), feed conversion poorest (3.15), and mortality highest (41.5%) at 50 cm depth, whereas 100-200 cm depth produced the best growth rates at warm water temperatures (> 21 ^oC). At 100-200 cm depth, weight gain was significantly (P<0.001) increased to 348-362 g per fish, feed conversion improved to 2.53-2.59 (P<0.01) and mortality reduced to 21-27% (P<0.001). Fish growth was significantly reduced (P<0.001) below 21 ^oC. Below 10 ^oC, fish stopped feeding and developed severe stress, fungal infection and high mortality. However, mortality rate was significantly reduced at 300 cm depth. Body lipid and protein were sharply decreased (P<0.001) with decreasing water temperature and pond depth, whereas body ash showed irregular patterns.     

Effects of dietary protein on growth and body composition of Nile tilapia, Oreochromis niloticus L.

The effects of dietary protein (25%, 30%, 35%, 40% and 45%) on growth, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition were investigated for four sizes (0.51, 45, 96 and 264 g) of Nile tilapia, Oreochromis niloticus L. In all four experiments, there was a progressive increase in growth with increasing dietary protein. In fry (0.51 g), significantly higher growth, survival and feed conversion were recorded for fish fed 40–45% rather than 25–35% protein diets. Similar trends for growth and FCR were also noted in 45 g fish. For larger (96 and 264 g) tilapia, significant differences in growth and FCR were found only between fish fed 25% and 30–45% protein diets. FCR and PER decreased with increasing weight of fish, and both were found to be negatively correlated with dietary protein level. Whole-body composition of the smallest fish was significantly influenced by dietary protein content. Percentage body protein of the fish fed 40–45% protein was higher than that of fish fed 25–35% protein diets, whereas lipid content decreased with increasing dietary protein level. In 45 g fish, both protein and lipid contents were higher in fish fed 25% and 30% protein diets than in those fed 35–45% protein diets. In larger tilapia, no significant influence of dietary protein level on body protein content was found. Percentage lipid decreased with increasing dietary protein level, and no definite trends in ash content were found. The results of these studies indicate that O. niloticus fry (0.51 g) should be reared on a practical diet containing 40% protein, and larger tilapia (96–264 g) on a diet containing 30% protein.     

不同营养素配比对点篮子鱼幼鱼生长及肌肉组成的影响

采用"金字塔"设计法,用蛋白质、脂肪、糖作为饲料组成变量配制21组饲料,对不同配比饲料影响平均体重(6.43±0.17)g的点篮子鱼(Siganus guttatus)幼鱼的生长效果进行研究,确定点篮子鱼幼鱼饲料中蛋白质、脂肪和糖的最佳拟合比例。各试验组饲料中蛋白质、脂肪和糖的范围分别设为27%~45%、3%~18%和15%~24%,实验共持续56 d。结果表明,饲料中蛋白质水平对鱼体的特定生长率和相对增重率影响最大,脂肪水平的降低对鱼体生长有利,糖水平对鱼体生长的影响较小。低蛋白水平下,即饲料蛋白质水平低于40.38%时,饲料中脂肪水平和糖水平的升高或降低均不利于鱼体的生长;蛋白质水平高于43.75%的高蛋白低脂肪低糖饲料不能明显提高鱼体生长性能。当饲料中蛋白质水平为40.38%~42.49%、脂肪水平为6.33%~7.87%、糖水平为19.52%~21.14%时,鱼体生长性能和饲料效率最为理想。肌肉测定结果表明,点篮子鱼这种杂食性鱼类,饲料中蛋白质水平大于38.44%时,蛋白质就能在点篮子鱼肌肉中较好地沉积,高蛋白低脂肪低糖饲料不会显著提高肌肉中蛋白质的沉积,却会使脂肪和糖原的沉积量增加。综合点篮子鱼的生长性能和肌肉营养组成的研究结果,确定点篮子鱼饲料中蛋白质、脂肪和糖的最佳拟合比例为42.49%、6.33%和21.14%。     

L-肉碱对鲫鱼生长和肌肉营养成分的影响

200尾均重25.1g的高背鲫按L-肉碱在饲料中添加量的不同(0,50,100,150,200mg/kg)随机分成5组,用于研究L-肉碱对鲫鱼生长及肌肉营养成分的影响。结果表明:鲫鱼饲料中添加50～100mg/kg的L-肉碱能显著提高鲫鱼的相对生长率、饲料效率,其中添加100mg/kg的L-肉碱效果最好,其相对生长率和饲料效率与对照组相比分别提高了122.4%和91.3%(P<0.05);在鲫鱼饲料中添加50～150mg/kg的L-肉碱时均能显著提高肌肉中蛋白质的含量,同时显著降低肌肉中脂肪的含量,其中添加150mg/kg的L-肉碱时肌肉中蛋白质含量比对照组提高4.04%,而脂肪含量降低了45.1%(P<0.05),但添加L-肉碱对鲫鱼的空壳率没有明显影响,各组差异均不显著。     

透明度、温度对强化培育罗非鱼的影响

主要对尼罗罗非鱼在强化培育期的最适温度和最适透明度做了进一步的探讨,在室内用了15个水槽,将透明度设为15～20cm、20～25cm、25～30cm三个组;将温度设为(20±0.5)℃、(22±0.5)℃、(24±0.5)℃、(26±0.5)℃、(28±0.5)℃五个组。在每个水槽中放入约3kg的鱼苗,规格为15尾/kg左右,通过每天对随机抽取的10条鱼测量其平均体重,求出每组每天的平均增重率,然后求出总的平均增重率,最后得出26℃为尼罗罗非鱼在强化培育期的最适温度,透明度在20～25cm时,尼罗罗非鱼生长最快。     

Influence of temperature on growth,feed consumption and chemical composition in the muscle of Pacu Piaractus mesopotamicus

The zootechnical performance of fish can be influenced by temperature through the induction of metabolic changes that are likely to affect growth and body composition. Thus, the objectives of this study were: (a) to examine the influence of five different temperatures (18, 21, 24, 27 and 30°C) on growth performance and metabolic parameters and (b) to evaluate the relationship of the protein efficiency ratio (PER) with the fillet proximate composition of Pacu juveniles. Growth and feed consumption (FC) were positively correlated with temperature (R² = .95), while PER and FC were negatively correlated with temperature (R² = .89). For the fillet composition, ethereal extract increased, and moisture decreased with the temperature. Protein content was lowest at 18 and 30°C and highest at 21, 24 and 27°C. The robust adjusted curve between PER and fillet protein content in relation to temperature showed the best result at 21°C. The obtained results indicate that Pacu juveniles reared between 21 and 27°C showed better protein efficiency with regard to FC, and this effect reflected better meat quality.     

The influence of a dietary lipid source on growth, muscle fatty acid composition and erythrocyte osmotic fragility of hybrid tilapia

An 8-week feeding trial was conducted to determine the effects of various dietary lipids on the growth, tissue proximate composition, muscle fatty acid composition and erythrocyte osmotic fragility of red hybrid tilapia, Oreochromis sp. Five isonitrogenous and isoenergetic semipurified diets were supplemented with 10% of either cod liver oil (CLO), sunflower oil (SFO), crude palm oil (CPO), crude palm kernel oil (CPKO), or a combination of 5% CLO with 5% palm fatty acid distillates (PFAD), respectively. There were no significant effects (P > 0.05) of diet on growth but fish fed the CLO diet showed a significantly (P< 0.05) poorer feed efficiency ratio compared to fish fed the CPO diet. Lipid deposition in fish muscle was mostly similar among fish fed the various diets but bone ash was significantly higher in fish fed the CPO and CPKO diets. Muscle lipids of fish fed palm oil-based diets did not increase in saturated fatty acids content but showed significantly lower polyunsaturated fatty acid (PUFA) concentrations compared to fish fed the CLO diet. The concentrations of individual PUFA in muscle lipids were strongly influenced by dietary PUFA concentrations. Dietary lipids did not markedly affect the structural integrity of erythrocyte membranes but the erythrocytes of tilapia fed the CPO diet were slightly more resistant to osmotic lysis. It was concluded that palm oil products, especially CPO, could be successfully used in the diet of hybrid tilapia based on its availability, cheaper costs and its potential ability to enhance oxidative stability due to its low PUFA content and high natural concentrations of antioxidants.