饲粮添加鱼油对蛋鸡免疫机能的影响

Effects of Dietary Fish Oil on Immune Function of Laying Hens

本试验旨在研究饲粮添加鱼油对蛋鸡体液和细胞免疫机能的影响。试验选用450只31周龄的健康海兰褐蛋鸡,随机分为5个组,每组6个重复,每个重复15只鸡。对照组饲喂玉米-豆粕型基础饲粮,试验组在基础饲粮基础上分别添加0.54%、1.08%、2.17%和4.34%的鱼油(二十二碳六烯酸含量分别为0.68、1.35、2.70和5.40 mg/g)。预试期1周,正试期12周。结果表明:1)饲粮添加鱼油对蛋鸡脾脏指数、胸腺指数及血清免疫球蛋白A含量无显著影响(P>0.05)。2)免疫后7和14 d,试验组蛋鸡血清禽流感H9抗体水平显著高于对照组(P <0.05),2.17%鱼油组抗体水平最高;免疫后28 d,试验组蛋鸡血清禽流感H9抗体水平有高于对照组的趋势(P<0.10)。免疫后7和14 d,试验组蛋鸡血清新城疫抗体水平显著高于对照组(P<0.05);免疫后28 d,试验组蛋鸡血清新城疫抗体水平与对照组相比无显著差异(P>0.05)。3)与对照组相比,4.34%鱼油组蛋鸡脾脏白细胞介素-2和白细胞介素-6基因的相对表达量显著降低(P<0.05),1.08%和2.17%鱼油组蛋鸡脾脏白细胞介素-10和干扰素-γ基因的相对表达量显著提高(P<0.05)。4)除4.34%鱼油组外,饲粮补充鱼油对蛋鸡脾脏淋巴细胞刺激指数和凋亡率无显著影响(P> 0.05)。综上,饲粮添加0.54%～2.17%鱼油能较好地改善蛋鸡免疫机能,过高(4.34%)无益。

This experiment was conducted to investigate the effects of dietary fish oil on humoral and cellular immune function of laying hens.Four hundred and fifty healthy Hy-Line Brown laying hens of 31-week-old were randomly allotted into 5 groups with 6 replicates per group and 15 hens per replicate.The laying hens in the control group were fed a corn-soybean meal type basal diet,and those in experimental groups were fed the basal diets supplemented with 0.54%,1.08%,2.17%and 4.34%fish oil with 0.68,1.35,2.70 and 5.40 mg/g docosahexaenoic acid,respectively.The feeding trial lasted for 12 weeks after 1 week of adaption.The results showed as follows:1)dietary fish oil did not significantly affect the spleen index,thymus index and serum immunoglobulin A content of laying hens(P>0.05).2)The avian influenza virus H9 subtype antibody levels in serum of laying hens in experimental groups were significantly increased at 7 and 14 days after immunization compared with the control group(P<0.05),which in 2.17%fish oil group was the highest.At 28 days after immunization,the avian influenza virus H9 subtype antibody levels in serum of laying hens in experimental groups showed an increasing tendency compared with the control group(P<0.10).The Newcastle disease virus(NDV)antibody levels in serum of laying hens in experimental groups were significantly increased at 7 and 14 days after immunization compared with the control group(P<0.05),and at 28 days after immunization,the NDV antibody levels in serum of laying hens in experimental groups were not significantly different compared with the control group(P>0.05).3)Compared with the control group,the relative gene expression levels of interleukin-2 and interleukin-6 in spleen of laying hens in 4.34%fish oil group were significantly decreased(P<0.05),and the relative gene expression levels of interleukin-10 and interferon-γin spleen of laying hens in 1.08%and 2.17%fish oil groups were significantly increased(P<0.05).4)Dietary fish oil had no significant effects on stimulus index and apoptosis rate of lymphocytes in spleen of laying hens except for 4.34%fish oil(P>0.05).In conclusion,dietary 0.54%to 2.17%fish oil can improve the immune function of laying hens but too high(4.34%)has no benefit.