酶解鸡血球蛋白粉替代鱼粉对卵形鲳鲹(Trachinotus ovatus)幼鱼生长性能、抗氧化能力、免疫力及肠道菌群的影响

Effects of Enzymolytic Chicken Hemoglobin Meal Replacing Fish Meal on Growth Performance,Antioxidant Capacity,Immunity and Intestinal Flora of Juvenile Trachinotus ovatus

本试验旨在研究酶解鸡血球蛋白粉替代鱼粉对卵形鲳鲹幼鱼生长性能、血浆生化和免疫指标、血细胞数、肠道形态、肝脏抗氧化能力及肠道菌群的影响。挑选300尾平均体质量为(6.66±0.17)g的健壮的卵形鲳鲹,随机分为4组,每组3个重复,每个重复25尾。对照组(P0组)投喂基础饲料,试验组分别投喂以酶解鸡血球蛋白粉替代基础饲料中1.5%(P1.5组)、3.0%(P3.0组)和4.5%(P4.5组)鱼粉的等氮等脂饲料。试验期8周。结果表明:1)P3.0和P4.5组的终末体质量、增重率、特定生长率、摄食量和蛋白质效率显著低于P0和P1.5组(P<0.05)。2)各组之间全鱼水分、粗灰分、粗蛋白质和粗脂肪含量没有显著差异(P>0.05)。3)P1.5组的血浆葡萄糖(GLU)、甘油三酯(TG)、低密度脂蛋白(LDL)含量和谷草转氨酶(AST)活性显著低于P0、P3.0和P4.5组(P<0.05)。4)P1.5和P3.0组的血浆补体3(C3)和补体4(C4)含量显著高于P0和P4.5组(P<0.05),P1.5、P3.0和P4.5组的血浆碱性磷酸酶(ALP)活性及血液白细胞和红细胞数量显著高于P0组(P<0.05)。5)P3.0和P4.5组的肝脏过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性显著低于P0和P1.5组(P<0.05),P4.5组的肝脏丙二醛(MDA)含量显著高于P1.5、P3.0和P0组(P<0.05)。6)P3.0和P4.5组的中肠和后肠的绒毛高度显著低于P0和P1.5(P<0.05),P4.5组的中肠和后肠绒毛宽度显著低于P0和P1.5(P<0.05)。7)在门水平上,P1.5和P4.5组的肠道蓝藻门和放线菌门相对丰度显著高于P0组(P<0.05),肠道变形菌门、厚壁菌门和拟杆菌门相对丰度显著低于P0组(P<0.05)。在属水平上,P1.5和P4.5组的肠道PCC-6307蓝藻属和分支杆菌属相对丰度显著高于P0组(P<0.05),肠道乳酸球菌属、Phreatobacter、未定义的α-变形菌属和伊丽莎白菌属相对丰度显著低于P0组(P<0.05)。由此可见,饲料中酶解鸡血球蛋白粉替代1.5%鱼粉可增强卵形鲳鲹幼鱼机体免疫力,改善肠道菌群结构,对生长性能、肠道形态和抗氧化能力的作用与鱼粉相似。

This experiment was conducted to study the effects of enzymolytic chicken hemoglobin meal replacing fish meal on growth performance,plasma biochemical and immune parameters,blood cell counts,intestinal morphology,hepatic antioxidant capacity and intestinal flora of juvenile Trachinotus ovatus.A total of 300 robust Trachinotus ovatus with the average body weight of(6.66±0.17)g were randomly divided into 4 groups with 3 replicates per group and 25 fish per replicate.Fish in the control group were fed a basal diet,and others in experimental groups were fed isonitrogenous and isolipid diets with enzymolytic chicken hemoglobin meal replacing 1.5%(P1.5 group),3.0%(P3.0 group)and 4.5%(P4.5 group)fish meal in the basal diet,respectively.The experiment lasted for 8 weeks.The results showed as follows:1)the final body weight,weight gain rate,specific growth rate,feed intake and protein efficiency ratio in P3.0 and P4.5 groups were significantly lower than those in P0 and P1.5 groups(P<0.05).2)There were no significant differences in the contents of moisture,ash,crude protein and ether extract in whole fish among all groups(P>0.05).3)The plasma glucose(GLU),triglyceride(TG),low density lipoprotein(LDL)contents and glutamic-oxalacetic transaminase(AST)activity in P1.5 group were significantly lower than those in P0,P3.0 and P4.5 groups(P<0.05).4)The contents of complement 3(C3)and complement 4(C4)in plasma in P1.5 and P3.0 groups were significantly higher than those in P0 and P4.5 groups(P<0.05),and the plasma alkaline phosphatase(ALP)activity and numbers of white blood cells and red blood cells in blood in P1.5,P3.0 and P4.5 groups were significantly higher than those in P0 group(P<0.05).5)The activities of catalase(CAT),superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in liver in P3.0 and P4.5 groups were significantly lower than those in P0 and P1.5 groups(P<0.05),and the liver malondialdehyde(MDA)content in P4.5 group was significantly higher than that in P0,P1.5 and P3.0 groups(P<0.05).6)The midgut and hindgut villus height in P3.0 and P4.5 groups was significantly lower than that in P0 and P1.5 groups(P<0.05),and the midgut and hindgut villus width in P4.5 group was significantly lower than that in P0 and P1.5 groups(P<0.05).7)At the phylum level,the relative abundances of Cyanobacteria and Actinobacteriota in intestine in P1.5 and P4.5 groups were significantly higher than that in P0 group(P<0.05),and the relative abundances of Proteobacteria,Firmicutes and Bacteroidota in intestine were significantly lower than that in P0 group(P<0.05).At the genus level,the relative abundances of Cyanobium_PSC-6307 and Mycobacterium in intestine in P1.5 and P4.5 groups were significantly higher than those in P0 group(P<0.05),and the relative abundances of Lactococcus,Phreatobacter,Alphaproteobacteria_unclassified and Elizabethkingia in intestine were significantly lower than those in P0 group(P<0.05).In conclusion,the replacement of fish meal with 1.5%enzymolytic chicken hemoglobin meal in diet can enhance body immunity,improve the intestinal flora structure,and have similar effects on growth performance,intestinal morphology and antioxidant capacity as fish meal.