乳酸乳球菌L19对乌鳢生长、免疫功能及抗氧化能力的影响

Effects of Lactococcus lactis L19 on Growth,Immunity and Antioxidant Capacity of Channa argus

试验旨在探讨乳酸乳球菌(Lactococcus lactis)L19对乌鳢生长、免疫功能及抗氧化能力的影响。将540尾初始体质量为(8.68±0.22)g的乌鳢随机分为6组,每组3重复,在基础饲料中分别添加0(对照组)、1.0×10^(6)(10^(6)组)、1.0×10^(7)(10^(7)组)、1.0×10^(8)(10^(8)组)、1.0×10^(9)(10^(9)组)CFU/g及1.0×10^(10)(10^(10)组)CFU/g L.lactis L19,配制成6种等氮等脂的试验饲料,进行为期8周的饲养试验。饲养试验结束后,测定乌鳢生长性能、血清免疫指标及肝脏和肠道中抗氧化酶活性。结果表明:L.lactis L19添加量分别为1.0×10^(7)、1.0×10^(8)、1.0×10^(9) CFU/g组和1.0×10^(10) CFU/g组乌鳢的终末体质量(FBW)、增重率(WG)、特定生长率(SGR)、饲料效率(FER)及蛋白质效率(PER)均显著高于对照组(P<0.05)。L.lactis L19添加量分别为1.0×10^(8)、1.0×10^(9) CFU/g组和1.0×10^(10) CFU/g组乌鳢血清中的免疫球蛋白M(IgM)和补体4(C4)含量均显著高于对照组(P<0.05),L.lactis L19添加量为1.0×10^(7)、1.0×10^(8)、1.0×10^(9) CFU/g和1.0×10^(10) CFU/g组的乌鳢血清中的酸性磷酸酶(ACP)、碱性磷酸酶(AKP)和溶菌酶(LZM)活性及补体3(C3)含量均显著高于对照组(P<0.05),且添加1.0×10^(8) CFU/g组达到最高。在肝脏和肠道中,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性均随L.lactis L19添加量的增加呈先升高后降低的趋势,且各指标均以L.lactis L19添加量为1.0×10^(8) CFU/g组的效果最好。在本试验条件下,饲料中添加适量L.lactis L19可有效促进乌鳢生长、饲料利用,提高免疫功能及抗氧化能力,且在乌鳢配合饲料中L.lactis L19的适宜添加量为1.0×10^(8) CFU/g。

This study aimed to investigate the effects of Lactococcus lactis L19 on growth,non-specific immunity and antioxidant capacity of Channa argus.A total of 540 C.argus(8.68±0.22)g were randomly divided into six equal groups.Fish were fed with basal diets supplemented with 0,1.0×10^(6),1.0×10^(7),1.0×10^(8),1.0×10^(9) CFU/g and 1.0×10^(10) CFU/g of L.lactis L19 for eight weeks.The basal diet consisted of 42.42% crude protein and 9.13% crude lipid.After feeding,the growth performance,serum non-specific immune indexes and antioxidant enzyme activity in liver and intestine were measured.The results indicated that the final body weight(FBW),weight gain(WG),specific growth rate(SGR),feed efficiency ratio(FER)and protein efficiency ratio(PER)in the 1.0×10^(7),1.0×10^(8),1.0×10^(9) CFU/g and 1.0×10^(10) CFU/g of L.lactis L19 groups were all significantly higher than that of the control group(P<0.05). The serum contents of immunoglobulin M(IgM)and complement 4(C4)in 1.0×10^(8),1.0×10^(9) CFU/g and 1.0×10^(10) CFU/g of L.lactis L19 groups were significantly higher than that of the control group(P<0.05).The serum activities of acid phosphatase(ACP),alkaline phosphatase(AKP)and lysozyme(LZM),and contents of complement 3(C3)in 1.0×10^(7),1.0×10^(8),1.0×10^(9) and 1.0×10^(10) CFU/g of L.lactis L19 groups were all significantly higher than the control group(P<0.05),and peaked in the 1.0×10^(8) L.lactis L19 group.In liver and intestine,the activities of superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)increased first and then decreased with the increase of the L.Lactis L19 concentration,while the malondialdehyde(MDA)content showed an opposite trend.And the 1.0×10^(8) CFU/g of L.lactis L19 group showed the best antioxidant capacity.Under the conditions of this experiment,supplemented an appropriate amount of L.lactis L19 with feed could effectively promote the growth and utilization of feed,improve non-specific immunity and antioxidant capacity.The optimal supplementation amount of L.lactis L19 in the feed of C.argus was 1.0×10^(8) CFU/g.