【作者】 李彬；

【导师】 梁旭方；

【作者基本信息】 华中农业大学 ， 水产养殖学， 2014， 硕士

【摘要】 本论文旨在探讨饲料中蛋白质水平对三种规格草鱼(Ctenopharyngodon idellus)生长、饲料利用和氮代谢的影响,并得出三种规格草鱼对饲料蛋白质的最适需求量。主要内容如下：1、以秘鲁鱼粉和酪蛋白为蛋白源制备蛋白水平分别为20%、25%、30%、35%、40%和45%的6种等能饲料。选取初始体重为(12.17±0.92)g的草鱼随机分为6组,每组3个重复,每个重复30尾鱼。实验鱼饲养于循环水养殖缸(300L)中,每天投喂3次(08：00、12：00和16：00),养殖周期为8周。结果表明：饲料蛋白质水平对草鱼的增重率、特定生长率、饲料效率和摄食量均影响显著(P<0.05),其中30%蛋白质组最高。蛋白质保留率、蛋白质效率和血糖浓度随蛋白水平的升高而显著降低(P<0.05)。25%蛋白质组的肝体比和肠脂比最大,35%蛋白质组的肝脏粗脂肪含量显著高于其他蛋白质组(P<0.05)。最高的全鱼粗蛋白含量和粗脂肪含量分别出现在40%和30%蛋白质组。肌肉粗脂肪含量、血清总蛋白、血清尿素氮含量随蛋白水平的升高显著增加(P<0.05)。各蛋白质组的脏体比、血清丙氨酸转氨酶和血清天冬氨酸转氨酶活性均无显著差异(P>0.05)。根据生长和饲料效率得出,12.17g草鱼的最适蛋白质需求量为31.29%-33.17%。2、以秘鲁鱼粉和酪蛋白为蛋白源制备蛋白水平分别为15%、20%、25%、30%和35%的5种等能饲料。选取初始体重为(209±10)g的草鱼180尾,随机分为5组,每组3个重复,每个重复12尾鱼。实验鱼饲养于网箱(2m×2m×2m)中,每天投喂2次(08：00和16：00),养殖周期为8周。结果表明：饲料蛋白水平对草鱼的增重率、特定生长率、饲料效率均影响显著(P<0.05),其中25%蛋白质组最高。15%蛋白质组的摄食率显著高于其它蛋白组(P<0.05)。蛋白质保留率、蛋白质效率、脏体比和全鱼粗脂肪含量随蛋白水平的升高而显著降低(P<0.05)。各蛋白质组的成活率、肝体比、肠脂比、血清丙氨酸转氨酶活性和血清天冬氨酸转氨酶活性均无显著差异(P>0.05)。全鱼粗蛋白含量、血清总蛋白、血清尿素氮、肝脏天冬氨酸转氨酶活性、肝脏谷氨酸脱氢酶活性和肌肉腺苷酸脱氨酶活性随蛋白水平的升高显著增加(P<0.05),而肝脏丙氨酸转氨酶活性先增加后稳定,这表明高蛋白质组(30%和35%蛋白质组)相对于低蛋白质组(15%和20%蛋白质组)有较多的蛋白质用于分解代谢提供能量。根据生长和饲料效率得出,209g草鱼的最适蛋白质需求量为26.5%-27.2%。3、以秘鲁鱼粉和酪蛋白为蛋白源制备蛋白水平分别为15%、20%、25%、30%和35%的5种等能饲料。选取初始体重为(454±8)g的草鱼随机分为5组,每组3个重复,每个重复10尾鱼。实验鱼饲养于网箱(2m×2m×2m)中,每天投喂2次(08：00和16：00),养殖周期为8周。结果表明：饲料蛋白水平对草鱼的增重率、特定生长率、饲料效率均影响显著(P<0.05),其中25%蛋白质组最高。35%蛋白质组的摄食率显著低于其它蛋白组(P<0.05)。蛋白质保留率、蛋白质效率、脏体比、肝体比和肠脂比随蛋白水平的升高而显著降低(P<0.05)。30%蛋白质组的全鱼粗脂肪含量最高,显著高于15%、20%和25%蛋白质组(P<0.05),肝脏和肌肉营养成分均无显著性差异(P>0.05)。各蛋白质组的成活率、血清总蛋白浓度、血糖浓度、血清丙氨酸转氨酶活性、血清天冬氨酸转氨酶活性和肝脏丙氨酸转氨酶活性均无显著差异(P>0.05)。血清尿素氮、肝脏天冬氨酸转氨酶活性、肝脏谷氨酸脱氢酶活性和肌肉腺苷酸脱氨酶活性随蛋白水平的升高显著增加(P<0.05)。根据生长和饲料效率得出,454g草鱼的最适蛋白质需求量为25.82%-26.24%。更多还原

【Abstract】 The present study was to investigate the effect of dietary protein levels on growth, feed utilization and nitrogen metabolism of grass carp(Ctenopharyngodon idellus).1. Six isoenergetic diets were formulated with20%,25%,30%,35%,40%and45%protein level. Fish (12.24±0.34g) were randomly distributed into six groups each with three replicates in tanks (300L). Fish were fed thrice daily (08:00,12:00and16:00) to apparent satiation for8weeks. The results showed that weight gain and feed utilization were significantly affected by dietary protein levels (P<0.05). Fish fed the diet with30%protein had the highest weight gain, specific growth ratio, feed efficiency ratio and feed intake than other groups. Protein retention efficiency, protein efficiency ratio and serum glucose inversely correlated with dietary protein levels (P<0.05).25%protein group had the highest hepatosomatic index and intraperitoneal fat ratio, liver crude lipid in35%protein group was significantly higher than other protein group(P<0.05).The highest protein content and lipid content of whole body were found in40%and30%protein group. The contents of serum total protein, muscle crude lipid and blood urea nitrogen were significantly increased with the increasing of dietary protein levels (P<0.05). There were no significant differences on viscerosomatic index, activities of serum alanine aminotransferase and serum aspartate aminotransferase (P>0.05).The dietary optimal protein for grass carp from weight gain and feed efficiency ratio estimated using the second order polynomial regression was ranged from31.29%to33.17%.2. Five isoenergetic diets were formulated with15%,20%,25%,30%and35%protein level. Fish (209±10g) were randomly distributed into five groups each with three replicates in net cages (2m×2m×2m). Fish were fed twice daily (08:00and16:00) to apparent satiation for8weeks. The results showed that weight gain and feed utilization were significantly affected by dietary protein levels (P<0.05). Fish fed the diet with25%protein had the highest weight gain, specific growth ratio and feed efficiency ratio than other groups. Protein retention efficiency, protein efficiency ratio, viscerosomatic index and lipid content of whole body inversely correlated with dietary protein levels (P<0.05). There were no significantly differences on survival, hepatosomatic index, intraperitoneal fat ratio, activities of serum alanine aminotransferase and serum aspartate aminotransferase (.P>0.05).30%protein group had the highest crude protein contents of whole body. Protein content of whole body, serum total protein, blood urea nitrogen, the activities of aspartate aminotransferase, glutamate dehydrogenase in liver and adenosine5’-monophosphate deaminase in muscle were significantly increased with the increasing of dietary protein levels (P<0.05). This denoted increased catabolism of protein to supply energy with the increasing of dietary protein levels. The dietary optimal protein for grass carp from specific growth ratio and feed efficiency ratio estimated using the second order polynomial regression was ranged from26.5%to27.2%.3. Five isoenergetic diets were formulated with15%,20%,25%,30%and35%protein level. Fish (454±8g) were randomly distributed into five groups each with three replicates in net cages (2m×2m×2m). Fish were fed twice daily (08:00and16:00) to apparent satiation for8weeks. The results showed that weight gain and feed utilization were significantly affected by dietary protein levels (P<0.05). Fish fed the diet with25%protein had the highest weight gain, specific growth ratio and feed efficiency ratio than other groups. Protein retention efficiency, protein efficiency ratio, viscerosomatic index, hepatosomatic index and intraperitoneal fat ratio inversely correlated with dietary protein levels (P<0.05).30%protein group had the highest crude lipid contents of whole body. The composition of liver and muscle were no significantly differences (P>0.05). There were no significantly differences on survival, serum total protein, serum glucose, activities of serum alanine aminotransferase, activities of serum aspartate aminotransferase and activities of liver alanine aminotransferase (P>0.05). The content of blood urea nitrogen, the activities of aspartate aminotransferase, glutamate dehydrogenase in liver and adenosine5’-monophosphate deaminase in muscle were significantly increased with the increasing of dietary protein levels (P<0.05). The dietary optimal protein for grass carp from specific growth ratio and feed efficiency ratio estimated using the second order polynomial regression was ranged from25.82%to26.24%.更多还原