饲料中脂肪的含量对青鱼鱼种生长的影响

本文报导了利用青鱼鱼种在饲料中的蛋白质,醣、维生素和无机盐等保持适宜含量的条件下,研究不同含量脂肪对青鱼鱼种生长影响的试验结果。试验所用的脂肪为马面鲀鱼油。试验结果表明,青鱼鱼种饲料中适宜的脂肪含量为3-8％,最佳含量为6.5％。两批实验的结果基本一致。饲料中的脂肪含量对鱼体肌肉和肝脏生化组成有一定的影响。     

饲料中油脂的质和量对团头鲂生长的影响

研究在饲料蛋白水平，能量水平均能满足生长需要的前提下，饲料中添加不同含量及不同品质的脂肪对团头鲂鱼种水平的影响。试验所用的精制饲料用进口酪蛋白及脂肪，糊精、维生素，矿物质、纤维素加工而成，脂肪为豆油与鳕鱼肝油。     

饲料脂肪水平对长吻鱼危生长的影响

通过添加鱼油配制５种不同脂肪含量的饲料，以测定脂肪水平对长吻鱼危鱼种（平均体重１０ｇ）生长的影响。鱼油添加量按３％递增，范围为０～１２％，饲料脂肪含量为５％～１８％，蛋白质含量４５０％。结果显示，饲料脂肪水平对长吻鱼危鱼种的生长和饲料利用率有显著的影响，饲料脂肪水平在１５％～１８％时长吻鱼危生长率高，饵料系数低。说明了适当高的脂肪含量能够促进长吻鱼危鱼种的生长，并提高饲料效率。     

饲料中蛋白质和醣的含量对青鱼鱼种生长的影响

本文讨论了饲料中蛋白质和醣含量对青鱼鱼种生长的影响。试验饲料由酪蛋白、糊精、鱼肝油、羧甲基纤维素粉(CMC)、无机盐混合剂和适量的维生素组成。用于试验的青鱼鱼种的平均体重为37．12—48．32克，试验期间的水温为24—34℃，试验得到的数据，经统计分析表明，青鱼鱼种饲料的最适蛋白质含量为29．54—40．85％。饲料中蛋白质和醣含量之间存在着明显的交互作用，当蛋白质含量为37—43．3％，醣含量为9．5—18．6％时，青鱼鱼种生长最快。饲料的蛋白质含量对鱼体的蛋白质、脂肪和醣含量有一定影响，肝脏中蛋白质含量也受到饲料蛋白质含量的影响，肝醣含量则随饲料醣含量的增加而增加。饲料中蛋白质和醣的含量会影响青鱼鱼种的消化率，当饲料中蛋白质处于最适量而醣含量在30％以下时，鱼的蛋白质消化率大致为92％左右，醣含量过高将对蛋白质的消化率产生影响。饲料的组成对青鱼鱼种的血红蛋白含量影响不大。     

四种抗菌促长药物在团头鲂饲料中适宜添加量的初步研究

用正交法设计了九种不同配方的团头鲂鱼种饲料。饲养结果表明,团头鲂鱼种配合饲料中磺胺二甲嘧啶的适宜添加量为50×10-6,黄霉素为2×10-6,碘化酪蛋白为20×10-6,痢特灵为100×10-6。     

青鱼、草鱼、团头鲂的肌肉及有关天然饲料的生化组成分析

本文主要阐述不同生长阶段的青鱼、草鱼、团头鲂的肌肉及与这三种鱼食性有关的天然饲料生化组成。分析结果表明,三种鱼的肌肉中以水分含量最高,蛋白质、脂肪、灰分、醣依次减少。三种鱼处在不同生长阶段(即夏花、一龄鱼、二龄鱼和食用鱼),其肌肉生化组成特点是:水分随鱼体生长逐渐下降,呈显著的负相关,相关系数分别为青鱼r=-0.88,草鱼r=-0.94,团头鲂r=-0.93;脂肪含量随鱼体生长逐渐增加,青鱼和团头鲂呈显著的正相关,相关系数分别为r=0.96和r=0.94,雨草鱼的相关系数r=0.47,不显著;蛋白质、鱼、灰分含量的交幅不大,趋于相对稳定。三种鱼的肌肉蛋白质氨基酸组成基本相同,必需氨基酸含量(干重计)为氨基酸总量的50％以上,以食用鱼阶段相比较,青鱼的必需氨基酸含量占51.5％,草鱼和团头鲂的必需氨基酸分别占氦基酸总量的50％和46.7％,均可称得上高质量的完全蛋白质。青鱼的天然饲料(干物汁),螺蛳的蛋白质含量为53.18％,脂肪5.0％,醣17.3％;黄蚬的蛋白质含量为48.68％,脂肪10.15％,醣31.5％;草鱼的天然饲料(干物汁),宿根黑麦草的蛋白质含量为31.62％,脂肪6.43％,醅38％;苦草的蛋白质含量为18.89％,脂肪2.79％,醣36.22％。在这些天然饲料中,必需氨基酸的组分种类齐全,含量占氨基酸总量的50％左右;饲料的能量蛋白比(C/P比),螺蛳为61.4,黄蚬为84.64％,宿根黑麦草为107.13％,苦草为129.96。实验证明,这四种天然饲料的蛋白质,脂肪,醣的含量和C/P比,与青鱼、草鱼、团头鲂的营养需求相适应,可称为优良的天然饲料。本研究为我国主要养殖鱼类的营养学研究及鱼用饲料的开发提供了基础理论依据。     

饲料脂肪水平对长吻Wei生长的影响

通过添加鱼油配制５种不同脂肪含量的饲料，以测定脂肪水平对长吻Ｗｅｉ鱼种生长的影响。鱼油加量按３％递增，范围为０－１２％，饲料脂肪含量为５％－１８％，蛋白含量４５．０％。     

日本沼虾饲料最适蛋白质、脂肪含量及能量蛋白比的研究

本文研究了日本沼虾(Macrobrachium nipponense)饲料的最适蛋白质含量、脂肪含量及能量蛋白比。试验用饲料由酪蛋白、糊精、混合油、复合维生素和无机盐混合物等组成。本试验用的日本沼虾体重为 1.77±0.23克,试验期间水温为 21—25℃。用增重率、饲料系数和肝胰脏α-淀粉酶活力等作为评价指标。试验结果表明:日本沼虾配合饲料适宜蛋白质含量为 36.8—42.27％,适宜脂肪含量为6—12％。当配合饲料的蛋内质含量在适宜范围内,饲料能量蛋白比(C/P)为8千卡/克蛋白左右,每公斤配合饲料的总能量为3006—3561千卡是最为适宜的。当饲料总能量在一定范围内,随着饲料碳水化合物含量的增加,肝胰脏α-淀粉酶活力增强。     

翘嘴鲌鱼种饲料中脂肪适宜水平的初步研究

以鱼粉和酪蛋白为蛋白源,以鱼油和豆油的混合物(1︰1)为脂肪源,配制7种等氮不同脂肪水平(1.82%dm~15.02%dm)的试验饲料,饲养平均体重为2.85±0.15g的7组翘嘴鲌隔冬鱼种30d。试验结果表明,翘嘴鲌鱼种饲料中脂肪水平对鱼体生长、饲料系数和蛋白质校效率均有显著的影响(p<0.05)。饲料中适宜的脂肪水平为6.48%~8.78%。     

甲鱼配合饲料中蛋白质,脂肪以及醣类适宜含量初探

改变饲料中蛋白质，脂肪以及醣类的含量，设计一个三因素三水平的正交试验，初步探讨二龄甲鱼配合饲料中这三种成分的适宜含量，试验结果，配合饲料中蛋白质，脂肪和可消化醣类的适宜含量分别为４５％－４８．３％、４．２％－６．７％和２０％－２５％。     

草鱼酶纤颗粒饲料及营养代谢的研究

本文报道了酶纤颗粒饲料饲养效果、颗粒饲料营养组分对草鱼生长影响和草鱼对蛋白质需要量、消化率等营养代谢的研究结果。试验表明，利用从甘蔗造纸分筛出来的废渣——蔗糠，经EA-2 867纤维素霉菌将蔗糠纤维酶解成单糖，再接种培养白地霉，获得含粗蛋白10—12％的酶纤蛋白饲料，以此为主要原料制成的颗粒饲料，用来饲养草鱼，可以获得增产。试验中，还分析了草鱼鱼体蛋白质氨基酸组成，结果表明，当配制的颗粒饲料蛋白质氨基酸成分同鱼体一致时，鱼的生长良好。文末，讨论了酶纤颗粒饲料的前景并从鱼类营养学观点提出了配制鱼用颗粒饲料应注意的几个问题。     

Experimental and Practical Diet Evaluations with Juvenile Hybrid Striped Bass1

Culture of hybrid striped bass has been expanding in the United States and further growth has been predicted, however, several problem areas exist, including a lack of nutritional information. This series of studies offered reciprocal cross juvenile hybrids several of the commercially available feeds and several different types of purified experimental diets. Weight gain and feed efficiency of fish fed the commercially available feeds formulated to meet the general requirements of salmonids were better than fish fed feeds formulated to meet the nutritional requirements of catfish. Experimental diets containing casein as the primary protein source were unpalatable regardless of the level of fish oil added (6 or 12%) but were accepted if 10% menhaden fish meal was added. Addition of lower levels of fish meal resulted in decreasing degrees of acceptance. Thus, the minimum level of fish meal that elicited a feeding response appeared to be between 510% of the dry diet. A crystalline amino acid test diet was palatable, and weight gain of fish fed that diet was 65–91% of the weight gain recorded for fish fed the positive control diets. Addition of L-arginine, L-methionine or L-cystine to a purified diet containing casein did not result in dietary acceptance. Whole-body proximate composition offish revealed a general trend toward increased lipid levels with increasing levels of dietary lipid. All fish exhibited microvessicular hepatopathy, regardless of diet fed. Hepatocytes contained both glycogen and lipid in the cytoplasm.     

Strategies for further development of aquatic feeds

ABSTRACT: To date, aquatic feeds have depended heavily on fishmeal and fish oil as their source of protein and lipid. However, the feed industry is encountering shortfalls in the availability of these ingredients because of a decline in the number of fish captured in the wild and the increased human demand for some of the species currently being used for fishmeal and oil production. Therefore, efforts are now being directed in different parts of the world to finding alternative quality ingredients, which ideally are less expensive and readily available for use in practical diets. The data accrued have shown that a large proportion of both fishmeal and fish oil can be replaced by other protein and lipid sources. However, it is emphasized that an optimal essential amino acid balance be maintained and that the n-3 highly unsaturated fatty acid requirement be satisfied when combining economical protein and lipid ingredients. Newly developed feeds should aim at being nutrient-dense in order to reduce the output of solid, P and N waste. This can be done through improving nutrient availability, optimizing the digestible protein to energy balance of the diet, and replacing dietary fishmeal with alternate ingredients. These diets should also be effective for maintaining good health and improving disease resistance in fish through enhancement of immune responses. A wholesome approach to culturing fish would be to use appropriate feeding standards that are aimed not only at improving economic returns but also at developing a lasting cohabitation of sustainable aquaculture and a cleaner environment. Furthermore, in the 2lst century aquaculture would still retain its place as a prominent source of food protein, signifying that fish feed research remains a forceful area in discovering better feeds for the industry.     

Fisheries By-Catch and By-Product Meals as Protein Sources For Rainbow Trout Oncorhynchus mykiss

Abstract— Fisheries by-catch and by-product meals are portrayed as ingredients having a great potential as ingredients in aquaculture feeds. The present study was designed to evaluate the nutritional value of shrimp by-catch meal, shrimp processing waste meal, and two fish meals made from Pacific whiting (meal with and without solubles) for rainbow trout by determining apparent digestibilityof these ingredients and conducting a 12-wk feeding trial with juvenile fish (average initial weight 20 g/fish). Apparent digestibility coefficients (ADCs) for protein in diets containing by-catch and processing by-products were 76% for shrimp by-catch meal, 79% for shrimp processing waste meal, 88% for Pacific whiting meal without solubles, and 92% for Pacific whiting meal with solubles. ADCs for lipid were higher than 94% for all the diets. ADCs for energy were 57% for shrimp by-catch meal, 73% for shrimp processing waste meal, 70% for Pacific whiting meal without solubles, and 73% for Pacific whiting meal with solubles. Growth performance was significantly affected by dietary protein source. Fish fed the shrimp by-catch meal diet had weight gain and feed conversion ratios similar to that of fish fed the control diet with anchovy fish meal. Fish fed diets containing shrimp processing waste and Pacific whiting meal with solubles had significantly lower weight gain and higher feed conversion ratios than the control diet. Growth was significantly lower in fish fed the Pacific whiting meal diet compared to fish fed the anchovy fish meal. The lower growth of fish fed diets containing Pacific whiting meal appeared to be a result of lower feed intake, indicating perhaps a lower palatability of this ingredient. Additional research addressing processing methods, nutritional manipulations, and palatability enhancement is needed to improve potential of some fisheries byproduct meals as ingredients in the diets of rainbow trout.     

罗氏沼虾诱食促长剂效果试验

试验结果表明，诱食促长剂２号组与对照组具有显著的促长作用，其平均合格经对照组高２９．９５％，相对     

团头鲂（Megalobrama amblyocephala Yih）对12种饲料原料消化率和可消化能的测定↑（*）

本实验以三氧化二铬为指示剂测定了一冬龄团头鲂（ＭｅｇａｌｏｂｒａｍａａｍｂｌｙｏｃｅｐｈａｌａＹｉｈ）对１２种饲料原料的干物质、粗蛋白质、粗脂肪、无氮浸出物、总磷和总能量的表观消化率，首次报道了总磷消化率和可消化能。从表观消化率和可消化能的角度评价了１２种饲料原料的营养价值，为开发适于团头鲂的人工配合饲料提供了科学依据。     

Effect of replacing fish meal with soybean meal on growth,feed utilization and nitrogen and phosphorus excretion on rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)

The effect of replacing fish meal with soybean meal (SBM) pretreated with phytase on feeds of juvenile rainbow trout was evaluated in a 90-day feeding trial. The rainbow trout (initial body weight, 4.01 ± 0.02 g) were fed five isonitrogenous (crude protein, 44.97%) and isolipidic (crude lipid, 13.42%) feeds. Diets were formulated to contain phytase-pretreated SBM replacing 0, 20, 40, 60 and 80% of fish meal protein, respectively. The results showed that there was no significant difference in weight gain (WG) among fish fed S0, S20, S40 and S60 diets; however, a significant reduction of this variable occurred when 80% of fish meal protein was replaced by phytase-treated SBM (P < 0.05). Similarly, specific growth rate and protein efficiency ratio had a similar trend with WG. Apparent digestibility coefficient (ADC) of protein and lipid in the S80 diet was significantly lower than that of the other diets, and the ADC of phosphorus significantly increased with the increase of dietary phytase-treated SBM level. No significant differences among treatments were detected for moisture, protein, lipid and ash content in whole body and muscle samples. Nitrogen and phosphorus excretion indicated that fish meal replacement by phytase-treated SBM led to an increase in nitrogen excretion, but led to a reduction in total phosphorus excretion. The results of the present study show that 60% of fish meal could be replaced by phytase-treated SBM in diets of juvenile rainbow trout without compromising weight gain or feed efficiency. A quadratic equation according to regression analysis of weight gain against dietary phytase-treated SBM level indicated that the optimal level of dietary phytase-treated SBM replacement for maximum growth was 26.90%.     

Response of juvenile red drum (Sciaenops ocellatus) to practical diets supplemented with medium chain triglycerides

Medium chain triglycerides (MCT), mostly C₆–C₁₂, are physiologically active compounds which are readily absorbed, transported and appear to be preferentially utilized as an energy source but are not deposited in lipid stores in a variety of terrestrial animals. Consequently, the incorporation of MCT in feeds may allow the utilization of higher levels of lipids, possibly increasing protein sparing, without affecting the proximate composition of the fish. To evaluate the response of red drum to varying levels of menhaden fish oil (MFO) and MCT's supplements, two growth trials were conducted utilizing a basal diet containing 44% protein and 5.7% lipid. The first growth trial utilized an incomplete factorial design to evaluate the general response of red drum to MCT's and MFO. The final weights and feed utilization of the fish was significantly affected by lipid source and level of supplementation as well as their interaction. In general, final weights of the fish and feed utilization were significantly higher for fish receiving diets supplemented with 0,4 or 8% MFO and lowest in fish offered the basal diets supplemented with 4% MCT. The performance of fish receiving diets supplemented with 8% MCT or a combination of 4% MFO and 4% MCT was intermediate. In the second experiment, low levels of MCT (0–4%) were evaluated in conjunction with low (3%) and high (8%) lipid supplement to the basal diet. Although, not significantly different from the high lipid basal diet, the largest fish and best feed utilization were found in fish offered the high lipid diet containing 1% MCT. However, as the level of MCT supplement was increased performance of the fish in terms of growth and feed utilization was reduced. Increasing the levels of MCT in the diet resulted in a reduction of intraperitoneal fat deposition. The fatty acid profiles of the intraperitoneal fat as well as the polar and neutral lipid fractions from the liver were determined. In general lipid content of the selected tissues reflected the FA profile of the diet. Based on FA profiles of the intraperitoneal fat, it appears that MCT are incorporated into fat stores of red drum. Based on the observed results, the response of red drum to MCT appear similar to other vertebrates but that MCT are incorporated into lipid stores. The incorporation of MCT in diets appears to be a suitable mechanism to reduce excessive lipid deposition in fish; however, with the exception of high lipid diet supplements may result in poor performance of the fish.     

Utilization of combined extruded soybean and corn gluten meals as feed ingredients for juvenile rainbow trout,Oncorhynchus mykiss diet

In this study, feeding experiment and subsequent digestibility trial were performed to investigate the utilization of extruded soybean meal (SBM) and corn gluten meal (CGM) as feed ingredients for juvenile rainbow trout. Plant ingredients have undergone extrusion at low temperature (100°C, LT) or high temperature (150°C, HT) for 30 s. Four isonitrogenous (44%, crude protein) and isolipidic (14%, crude lipid) diets were formulated. Control diet is fishmeal based while a combined (1:1) non‐extruded SBM and CGM for NE diet, LT SBM and LT CGM for LT diet and HT SBM and HT CGM for HT diet. Two hundred forty rainbow trout juveniles (7.8 g average body weight) were randomly divided into 12 rectangular 60 L glass aquaria and offered four different diets in triplicate. Fish were fed at satiation twice a day, six days a week for 12 weeks. Phosphorus in phytic acid level of extruded ingredients decreased through extrusion cooking. Final weight, weight gain, SGR and PER of fish fed HT diet were significantly (p < .05) higher than those fed with NE diet. Apparent digestibility coefficient for protein of LT and HT diets is significantly higher than of NE diet. The results of this study demonstrated that HT extruded SBM and CGM are suitable feed ingredients for rainbow trout diet without compromising fish growth, feed utilization and fish body composition.     

Effects of fish oil and partial fish meal substitution with oilseed oils and meals on growth performance, nutrient utilization and health of the rainbow trout Oncorhynchus mykiss

A feeding trial was conducted to investigate the effects of the replacement of dietary fish meal and fish oil with oilseed meals (soybean or canola) and canola oil on growth, nutrient utilization, body composition, diet digestibility and hematological parameters of rainbow trout Oncorhynchus mykiss. Seven diets were used; the control diet (designated FM) contained fish meal and fish oil as the main protein and lipid sources. For the experimental diets, 40% of fish meal protein was substituted with soybean meal, canola meal or a soybean/canola meal mixture, and these diets (designated SM, CM and SCM, respectively) contained fish oil as the lipid source. Three additional diets (SM?+?CO, CM?+?CO and SCM?+?CO) were formulated with the same vegetable protein meals but with fish oil replaced by canola oil. Fish were fed twice daily to apparent satiation for 11?weeks. The growth of fish fed the CM?+?CO diet was significantly lower than that of fish fed the FM, SCM, SM?+?CO and SCM?+?CO diets. The feed conversion ratio (FCR) was significantly better in fish fed the FM and SCM?+?CO diets than in fish fed the CM and CM?+?CO diets. Furthermore, feed intake was significantly lower for fish fed the CM?+?CO diet than in fish fed the SCM diet, and lipid digestibility of the CM?+?CO diet was significantly lower than that of all other diets. No significant differences of body composition were observed. Circulating leukocyte levels, leukocyte ratios and serum lysozyme activity remained unaffected by dietary treatment. However, it was observed that fish fed the CM?+?CO diet displayed hematocrit levels significantly lower (P?<?0.05) than that of fish fed the other diets. The results indicate that when diets contain either fish oil or canola oil, canola meal and soybean meal can be incorporated into rainbow trout feeds at a combined 32% inclusion level (replacing 40% of fish meal protein) without inducing significant negative effects on growth, nutrient utilization or health.