【作者】 林仕梅；

【导师】 麦康森；

【作者基本信息】 中国海洋大学 ， 水产养殖， 2008， 博士

【摘要】 我国是世界罗非鱼养殖大国,占世界罗非鱼总产量的50%。近几年,我国罗非鱼产量和出口量都持续增长。但受养殖个体偏小、品质、安全以及饲料成本等因素影响,罗非鱼产业的健康发展受到一定制约。鉴于此,本文选择我国重要的经济鱼类——奥尼罗非鱼（Oreochromis niloticus×O.aureus）为研究对象,在室内淡水循环养殖系统中进行生长实验。比较研究植物蛋白源豆粕、菜粕、棉粕和花生粕对奥尼罗非鱼生长、健康和品质的影响,探讨奥尼罗非鱼对不同植物蛋白源的耐受能力,确定其在水产饲料中的适宜用量。然后,通过蛋白源的联合作用,补充晶体氨基酸、外源酶制剂,以及解决植物蛋白源大量使用后对肝脏的危害等营养学途径,来提高水产养殖动物对植物蛋白源的利用。研究内容包括:（1）不同植物蛋白源对奥尼罗非鱼生长、体组成、消化酶活力和肝功能的影响;（2）实用饲料中豆粕替代鱼粉对奥尼罗非鱼生长、体组成的影响;（3）菜粕、棉粕替代豆粕对奥尼罗非鱼生长、体组成和免疫力的影响;（4）实用饲料中添加结晶蛋氨酸对奥尼罗非鱼生长、体组成的影响;（5）复合酶制剂对奥尼罗非鱼生长和饲料利用的影响;（6）活力健肝素LH-3对罗非鱼生长和肝功能的影响。主要研究结果如下:1.在含鱼粉14%的基础上,分别以豆粕（SBM）、菜粕（RSM）、棉粕（CSM）和花生粕（PNM）作为唯一植物蛋白源,配制4种等氮等能实验饲料。结果表明,不同植物蛋白源SBM、RSM、CSM和PNM对罗非鱼生长和饲料利用率有显著影响（P＜0.05）。SBM组罗非鱼的末重、增重率、特定生长率、饲料系数和蛋白质效率指标表现最佳,与CSM组差异不显著（P＞0.05）,而RSM组表现最差。PNM组鱼体水分含量显著低于其他试验组（P＜0.05）,而各试验组鱼体蛋白含量、粗灰分含量、鱼体肥满度、脏体比以及肝糖原、肝体比在各组间均差异不显著（P＞0.05）。SBM组的肠蛋白酶活力最高,与CSM组差异不显著（P＞0.05）。而RSM组的肠和肝蛋白酶活力最低（P＜0.05）。各实验组罗非鱼肠和肝脏的淀粉酶活力组间差异均不显著（P＞0.05）。不同植物蛋白源SBM、RSM、CSM和PNM对罗非鱼肝脏谷草转氨酶（GOT）、谷丙转氨酶（GPT）活性、超氧化物歧化酶（SOD）和肝脂含量均有显著影响（P＜0.05）。这四个值均以SBM组为最好,而以RSM组最差。不同植物蛋白源对罗非鱼的生长和健康产生的影响不同,饲料中含36%豆粕或含39%棉粕不会影响罗非鱼的生长,而饲料中含50%RSM对罗非鱼生长和健康是不利的。2.在一种实用饲料配方（鱼粉16%;豆粕12%）的基础上,用豆粕蛋白（SP）分别替代鱼粉蛋白（FP）质量的25%、50%、75%和100%配制成4种等能等氮的试验饲料,其中含34%～0%的鱼粉蛋白。结果表明,豆粕替代鱼粉对罗非鱼生长和饲料利用率有显著影响（P＜0.05）,当豆粕替代鱼粉蛋白量为25%以上时,随着替代水平的增加,罗非鱼的末重、增重率、特定生长率和蛋白质效率显著降低（P＜0.05）,替代25%鱼粉组的末重、增重率、特定生长率和蛋白质效率均显著高于替代50%、75%和100%组（P＜0.05）,而与对照组差异不显著（P＜0.05）。替代100%鱼粉组的饲料系数显著高于其他各试验组（P＜0.05）。100%替代鱼粉抑制罗非鱼的生长和对饲料的利用率（P＜0.05）。鱼体水分含量随豆粕替代鱼粉水平的增加而显著增加（P＜0.05）,相反,鱼体蛋白含量随豆粕替代鱼粉水平的增加而显著降低（P＜0.05）。豆粕替代鱼粉对脏体比、肝体比和肥满度均无显著影响（P＞0.05）。随豆粕替代鱼粉水平的增加,胃、肠和肝脏的蛋白酶活力均显著降低（P＜0.05）。各实验组罗非鱼胃、肠和肝脏的淀粉酶和脂肪酶活力在各组间差异均不显著（P＞0.05）。肝脏谷草转氨酶（GOT）和谷丙转氨酶（GPT）活力随豆粕替代鱼粉水平的增加而显著降低（P＜0.05）。豆粕蛋白替代25%鱼粉蛋白对罗非鱼是比较安全的,而豆粕蛋白完全替代鱼粉蛋白对罗非鱼的生长不利。3.用菜粕、棉粕按1:2的比例等量替代豆粕（6%、12%、18%）配制成3种等能等氮的无鱼粉饲料。结果表明,菜粕、棉粕替代不同水平豆粕对罗非鱼的生长、饲料利用和机体免疫力均产生了显著的影响（P＜0.05）。随菜粕、棉粕替代水平的增加,罗非鱼的生长、饲料系数和体蛋白含量均显著下降（P＜0.05）,而以无豆粕组影响最大。鱼体肝脂含量、肝体比（HSI）以及脏体比（VR）在组间差异不显著（P＞0.05）。无豆粕组血清GPT、GOT酶活力显著升高（P＜0.05）,而血清SOD、LZ酶活力显著降低（P＜0.05）。配方中棉粕和菜粕的总量超过52%对罗非鱼是不安全的。4.分别添加结晶DL-蛋氨酸0.00%、0.05%、0.10%、0.15%和0.20%,配制成5种含蛋氨酸0.45%、0.50%、0.55%、0.60%和0.65%的等能等氮的实验饲料（胱氨酸为0.52%）。结果表明:饲料中补充结晶DL-蛋氨酸,罗非鱼的瞬间生长率（SGR）、饲料系数（FCR）、蛋白沉积率（APR）和肝脂含量均得到明显改善（P＜0.05）。蛋氨酸0.50%水平显著提高了血清蛋氨酸的含量（P＜0.05）。但是对体蛋白含量和鱼体氨基酸含量均无显著影响（P＞0.05）。结晶蛋氨酸能够被罗非鱼有效利用,在罗非鱼饲料中添加适量的蛋氨酸是提高饲料蛋白质利用的一种有效途径。5.在基础饲料中分别添加0.00（对照组）、0.10和0.15 g kg^-1复合酶制剂（含中性蛋白酶、葡聚糖酶和木聚糖酶）,配制成3种等能等氮的实验饲料。试验结果表明:罗非鱼的瞬间生长率和饲料效率随复合酶添加水平的增加而显著上升（P＜0.05）。0.10 g kg^-1和0.15g kg^-1组罗非鱼的饲料摄入量（FI）显著低于对照组（P＜0.05）;0.15 g kg^-1水平组蛋白沉积率达到最高（P＜0.05）;各实验组之间蛋白质、脂肪和能量的表观消化率没有显著差异（P＞0.05）,而0.15 g kg^-1水平组干物质表观消化率显著高于对照组和低水平组（P＜0.05）;各实验组之间鱼的肥满度以及鱼体水分、蛋白质、脂肪和灰分含量均没有显著差异（P＞0.05）,但是脏体比、肝体比和肝脂肪含量随复合酶水平的增加而显著下降（P＜0.05）。随复合酶添加水平的增加,肝胰脏和肠蛋白酶活力与淀粉酶活力均显著升高（P＜0.05）。饲料中添加复合酶能显著改善罗非鱼的生长和提高对饲料的利用。6.在两个不同脂肪水平（3.2%,4.2%）的实用饲料配方的基础上,分别添加不同水平活力健肝素LH-3（0%、0.05%和0.1%）配制成5种等氮（粗蛋白为30%）试验饲料,在室内循环水族箱内饲喂奥尼罗非鱼（Oreochromis niloticus×O.aureus）8周。结果表明:活力健肝素LH-3能够改善罗非鱼的生长、肝脂含量和肝胰脏酶活力（GOT和GPT）,显著提高动物的抗氧化能力（SOD）（P＜0.05）。而鱼体干物质、蛋白质、脂肪和灰分含量以及脏体比、肝体比在组间差异均不显著（P＞0.05）。在以植物蛋白（＞50%）为基础的饲料中,添加LH-3能够改善罗非鱼肝的生理机能和促进生长。总之,通过植物蛋白源的联合作用可以有效替代饲料中鱼粉水平,补充晶体氨基酸、外源酶制剂和添加LH-3可以进一步改善奥尼罗非鱼对植物蛋白源的利用。更多还原

【Abstract】 Tilapia as an important food fish in developing countries is widely used in commercial farming systems for intensive aquaculture,and constitute the third largest group of farmed finfish,only after carps and salmonids,with an annual growth rate of about 11.5%.Currently, tilapia culture is widely practiced in many tropical and subtropical regions of the world, especinaly in China.More than 22 tilapia species are being cultured worldwide.However, hybrid tilapia Oreochromis niloticus×O.aureus is the most commercially cultured tilapia species in the South China,the culture scale has rapidly developed in the past few years.The shortage in world production of fish meal（the main conventional protein source） coupled with increased demand for fish meal in feeds for livestock and poultry is likely to reduce the dependence on fish meal as a single protein source in aquafeeds.Therefore,fish nutritionists have made several attempts to partially or totally replace fish meal with less expensive,locally available protein sources.But,the limiting factors in the utilization of plant protein sources by fish are related to diet palatability,digestibility and essential amino acid balance.Fish species, food habit and fish size also have effects on the utilization of plant protein sources by fish.The optimal dietary plant protein level usually to some degree varies by fish species and dietary protein level.It is very important aspects that how to improve the utilization of plant protein sources in aquafeeds.Therefore,specific strategies and techniques to increase the use of plant feedstuffs in aquafeeds and limit potentially adverse effects of bioactive compounds on farmed tilapia are discussed in this paper.The results can be briefly summarized as follows:1.This study evaluated the effects of four vegetable protein sources in the practical diet of hybrid tilapia on growth performance.Four isonitrogenous and isocaloric practical diets included only soybean meal（SBM）,rapeseed meal（RSM）,cottonseed meal（CSM） and peanut meal（PNM） as sole vegetable protein source with supplemental 14%fish meal（FM） were formulated.The results showed that the best performance in terms of final weight, specific growth rate（SGR）,relative weight gain ratio（RWGR）,feed conversion ratio（FCR） and protein efficiency ratio（PER） were shown in Diets SBM and CSM.The 5 parameters were significantly affected by Diet RSM（P＜0.05）.Whole body moisture content in Diet PNM was significantly lower than that of other 3 groups（P＜0.05）.The liver lipid content in Diet RSM was significantly higher than that of other 3 groups（P＜0.05）.And viscera ratio, hepatosomatic index,condition factor and the liver glycogen contents were not significantly affected（P＜0.05）.Protease activities of intestine in Diets SBM and CSM are significantly higher than that of other 2 groups（P＜0.05）,and the lowest protease activities of intestine and hepatopancreas in Diet RSM.No significant differences were observed in amylase activities of intestine and hepatopancreas among 4 diet groups（P＞0.05）,respectively.The highest activities of GPT,GOT and SOD in the liver were observed in Diet SBM and the poorest in Diet RSM.The results show that 36%SBM or 39%CSM may be included in the practical diets without inhibiting fish performance.The inclusion of 50%SBM resulted in significantly lower growth performance and feed utilization.2.This study evaluated the effects of replacing fish meal（FM） in the practical diet of hybrid tilapia with different soybean meal（SBM） levels on growth performance.Juvenile tilapia were fed either a mixture of FM and SBM based（control,Diet 1） diet or a soybean meal replacement isonitrogenous and isocaloric diet.The treatments（Diets 2-5） consisted replacing 25%,50%,75%and 100%FM protein with SBM protein,respectively.Relative weight gain ratio（RWGR）,specific growth rate（SGR） and protein efficiency ratio（PER） were significantly reduced as the proportion of soybean meal in the diets increased.The best performance in SGR,RWGR,feed conversion ratio（FCR） and PER were acquired in 16%FM （Diet 1） and 12%FM（Diet 2） group.It was found that these four ratios were affected significantly by no fish meal diet（Diet 5）（P＜0.05）.Whole body moisture content increased significantly（P＜0.05）,and protein content decreased with increasing dietary soybean meal levels.The viscera ratio,hepatosomatic index,condition factor,the liver lipid were not significantly affected by dietary treatments（P＜0.05）.Activities of protease,amylase and lipase in stomach,intestine and hepatopancreas of hybrid tilapia significantly decreased （P＜0.05） with increasing dietary soybean meal levels,respectively.GPT and GOT activities of the juvenile tilapia liver in no fish meal treatment are significantly lower than that of other 4 groups（P＜0.05）.The results show that in practical diets,FM can be replaced in terms of protein by 25%soybean meal protein without inhibiting fish performance.The inclusion of 100%protein from plant protein sources resulted in significantly lower growth performance and feed utilization.3.This study evaluates the effect using less-expensive RSM-CSM combo feed mixed with formally used soybean meal（SBM） for juvenile tilapia in different combinations.Four Soybean-based（the control,Diet 1） and RSM-CSM Combo（RSM:CSM = 1:2） were tested at equal nitrogen and caloric basis.The combinations include the replacement of SBM at 6% （Diet 2）,12%（Diet 3） and 18%（Diet 4） with the combo,respectively.The results showed that the best performance in terms of specific growth rate（SGR）,relative weight gain ratio （RWGR）,feed conversion ratio（FCR） and protein efficiency ratio（PER） were shown by the Diets 3 and 4.The 4 parameters were affected significantly by soybean-free diet（P＜0.05）.No significant differences were observed in dry matter,whole body moisture,protein,lipid and ash among 4 diet groups（P＞0.05）.Viscera ratio,hepatosomatic index and the liver lipid content did not change significantly（P＜0.05）.GPT and GOT activities of the tilapia serum in no-soybean meal treatment are significantly higher than that of other 3 groups（P＜0.05）. However,SOD and LZ activities in no-soybean meal groups are significantly lower than that of the other groups（P＜0.05）.The results show that RSM-CSM combo may be included in the diet up to 52%as a substitute for SBM.4.Five practical diets were formulated to contain five levels of methionine 0.45%,0.50 %,0.55%,0.60%,0.65%（containing cystine 0.52%） respectively.Results indicated that the practical diets containing free methionine improved the specific growth rate（SGR）,feed conversion ratio（FCR）,apparent protein retention（APR） and hepatopancreas lipid content in comparison with the basal diet（P＜0.05）.Significantly higher the concentration of serum free methionine was observed in juvenile hybrid tilapia fed diet with methionine 0.50%level than those of fish fed with other diets（P＜0.05）.But body protein and body amino acids contents of tilapia was not significantly difference among the five groups（P＞0.05）.Supplementation of free methionine was proved to be a significantly better way for improving protein utilization in plant proteins based diets of tilapia5.A commercial enzyme complex（containing neutral protease,Beta-glucanase and xylanase） was included at the level of 0.0（control group）,1.0 and 1.5g kg^-1 diet to formulate three test diets.The results showed that specific growth rate（SGR） and feed efficiency ratio （FER） significantly increased（P＜0.05） with increasing dietary enzyme levels.The highest feed intake（FI） was recorded in the group fed the control diet（P＜0.05）.The highest apparent protein retention（APR） was observed in fish fed the diet containing 1.5g kg^-1 diet（P＜0.05）. No significant differences were observed in the apparent digestibilities（ADC） of protein,lipid and gross energy among dietary treatments（P＞0.05）.However,the ADC of dry matter（DM） in fish fed high supplementation(1.5g kg^-1) was significantly higher than the control and low supplementation（P＜0.05）.There were no significant differences in condition factor,whole body moisture,protein,lipid and ash among dietary treatments.Viscera ratio,hepatosomatic index and the liver lipid decreased significantly with increasing enzyme（P＜0.05）.Both protease and amylase activities in the intestine and hepatopancreas of juvenile hybrid tilapia significantly increased（P＜0.05） with increasing dietary enzyme levels.The results suggested that enzyme supplementation can significantly improve growth performance and feed utilization in juvenile hybrid tilapia.6.Five practical diets were formulated to contain 2 levels of lipid and 3 levels of LH-3 （LH-3 contents in diets were 0.0%,0.05%and 0.1%） on the basis of isonitrogen.The results showed that the best performance in specific growth rate（SGR）,feed conversion ratio（FCR） and protein efficiency ratio（PER） were acquired in 0.05%and 0.1%LH-3 groups.It was found that the above three ratios were affected significantly by no LH-3 diet（P＜0.05）.No significant differences were observed in dry matter,whole body moisture,protein,lipid and ash among treatments（P＞0.05）.There were no significant differences in viscera ratio and hepatosomatic index among dietary tretaments（P＜0.05）.The liver lipid contents decreased significantly as LH-3 level increased in diets.GPT and GOT activities of the juvenile tilapia liver are significantly higher than that of the other groups（P＜0.05） as LH-3 level increased in diets. However,SOD activities of the juvenile tilapia liver in 0.1%LH-3 groups are significantly higher than that of the other groups（P＜0.05）.In conclusion,it is likely that a combination of plant-derived feed ingredients can effectively replace fish meal,and that supplements,such as amino acids,LH-3 and exogenous enzymes,will be needed to produce aquafeeds without fish meal that improve growth rates necessary for the economic production of farmed tilapia.更多还原