饲料中添加丁酸钠对黄颡鱼幼鱼非特异性免疫、抗氧化指标及肠道黏膜形态的影响

Effects of Dietary Sodium Butyrate on Non-Specific Immune,Antioxidant Indices and Intestinal Mucosal Morphology of Juvenile Yellow Catfish(Pelteobagrus fulvidraco)

本试验旨在探讨丁酸钠对黄颡鱼幼鱼非特异性免疫、抗氧化指标和肠道黏膜形态的影响。通过在基础饲料中添加0、250、500、1000和2000 mg/kg丁酸钠,配制5种等氮等脂的试验饲料。选取初始平均体重为(1.26±0.01)g黄颡鱼幼鱼600尾,随机分为5组,每组3个重复,每个重复40尾鱼,分别投喂5种试验饲料。试验期为56 d。结果表明:1)黄颡鱼血清溶菌酶(LZM)和一氧化氮合酶(NOS)活性在1000 mg/kg丁酸钠组达到最高,血清碱性磷酸酶(AKP)活性在250 mg/kg丁酸钠组达到最高,均显著高于未添加组(P<0.05)。黄颡鱼肝脏LZM和AKP活性在1000 mg/kg丁酸钠组达到最高,显著高于未添加组(P<0.05)。黄颡鱼肠道AKP和NOS活性在500 mg/kg丁酸钠组达到最高值,显著高于未添加组和2000 mg/kg丁酸钠组(P<0.05)。2)与未添加组相比,饲料中添加2000 mg/kg丁酸钠显著提高了黄颡鱼血清过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05)。1000 mg/kg丁酸钠组黄颡鱼血清超氧化物歧化酶(SOD)和肝脏GSH-Px活性显著高于未添加组(P<0.05)。500 mg/kg丁酸钠组黄颡鱼肠道SOD、CAT和GSH-Px活性显著高于未添加组(P<0.05),250、500、1000和2000 mg/kg丁酸钠组肠道丙二醛(MDA)含量显著低于未添加组(P<0.05)。3)与未添加组相比,饲料中添加500 mg/kg丁酸钠显著提高黄颡鱼前肠的绒毛长度、绒毛宽度、肌层厚度和后肠的绒毛长度、肌层厚度(P<0.05)。以黄颡鱼幼鱼血清NOS、SOD活性和前肠绒毛长度为评价指标,通过二次回归分析得出黄颡鱼幼鱼饲料中丁酸钠的适宜添加量分别为1275、1218和1489 mg/kg。

This experiment was conducted to investigate the effects of dietary sodium butyrate on non-specific immune,antioxidant indices and intestinal mucosal morphology of juvenile yellow catfish(Pelteobagrus fulvidraco).Five isonitrogenous and isolipidic experimental diets were formulated to contain sodium butyrate(SB)at 0,250,500,1000 and 2000 mg/kg,respectively.A total of 600 juvenile yellow catfish with the average body weight of(1.26±0.01)g were randomly divided into 5 groups with 3 replicates per group and 40 fish per replicate,and fish in the 5 groups fed their respective diet from the five isonitrogenous and isolipids diets for 56 days.The results showed as follows:the activities of serum lysozyme(LZM)and nitric oxide synthase(NOS)in 1000 mg/kg BS group and the activity of serum alkaline phosphatase(AKP)in 250 mg/kg SB group were the highest,and significantly higher than those in no-added group(P<0.05).The activities of liver LZM and AKP in 1000 mg/kg BS group were the highest,and significantly higher than those in no-added group(P<0.05).The activities of intestinal AKP and NOS in 500 mg/kg BS group were the highest,and significantly higher than those in no-added and 2000 mg/kg SB group(P<0.05).Serum catalase(CAT)and glutathione peroxidase(GSH-Px)activities in 2000 SB mg/kg group were significantly higher than those in no-added group(P<0.05).The activities of serum superoxide dismutase(SOD)and liver GSH-Px in 1000 mg/kg SB group were significantly higher than those in no-added group(P<0.05).There were significantly higher activities of intestinal SOD,CAT and GSH-Px in 500 mg/kg SB group than those in no-added group(P<0.05),and significantly lower content of intestinal malondialdehyde(MDA)in 250,500,1000 and 2000 mg/kg groups than those in no-added group(P<0.05).Villus length,villus width and muscular thickness in proximal intestine and villus length,muscular thickness in distal intestine were significantly higher in 500 mg/kg SB group compared with no-added group(P<0.05).With the serum NOS,SOD activities and villus length of proximal intestine as evaluation indices,the optimum dietary SB supplemental levels are 1275,1218 and 1489 mg/kg through quadratic regression analysis,respectively.