植物精油对大肠杆菌攻毒肉鸭生长性能、血清生化指标和免疫功能的影响

Effects of Plant Essential Oil on Growth Performance,Serum Biochemical Indexes and Immune Function of Ducks Challenged by Escherichia coli

本试验旨在探究饲粮中添加植物精油对大肠杆菌攻毒肉鸭生长性能、血清生化指标和免疫功能的影响。选用1日龄健康雄性北京鸭公鸭144只,随机分为3组,每组6个重复,每个重复8只鸭。对照组饲喂基础饲粮,2个试验组分别在基础饲粮中添加30 mg/kg维吉尼亚霉素(抗生素组)和200 mg/kg植物精油(植物精油组)。于试验的第7天分2次对所有鸭口腔灌服0.2 mL大肠杆菌O88(3×10~9CFU/mL),2次攻毒间隔8 h。试验期28 d。结果表明:1)与对照组相比,饲粮中添加抗生素和植物精油显著提高了9日龄体重及1~9日龄平均日增重(P <0.05),饲粮中添加植物精油显著或极显著降低了1~9日龄及1~28日龄料重比(P<0.05或P<0.01);抗生素组和植物精油组死淘率分别下降了6.25和4.17个百分点。2)与对照组相比,饲粮中添加植物精油极显著提高了14日龄的法氏囊指数(P<0.01),饲粮中添加抗生素显著提高了28日龄的脾脏和法氏囊指数(P<0.05)。3)与对照组相比,饲粮中添加植物精油显著或极显著降低了28日龄血清总蛋白和球蛋白含量(P<0.05或P<0.01)。4)与对照组相比,饲粮中添加植物精油显著或极显著提高了9日龄血清免疫球蛋白G(IgG)含量以及9、14、28日龄血清免疫球蛋白M(IgM)含量(P<0.05或P<0.01);饲粮中添加抗生素极显著提高了9日龄血清IgG含量以及14日龄血清IgM含量(P<0.05)。5)与对照组相比,饲粮中添加植物精油显著降低了9、28日龄空肠Toll样受体4(TLR4)含量,9、14、28日龄空肠肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)含量,以及14日龄空肠白细胞介素-6(IL-6)含量(P<0.05);饲粮中添加抗生素显著了降低9、14、28日龄空肠TLR4、IL-1β、IL-6含量以及9、28日龄空肠TNF-α含量(P<0.05)。综上,在大肠杆菌攻毒作用下,饲粮中添加植物精油能够替代抗生素用于缓解机体炎症反应,减少机体器官损伤以及空肠炎症细胞因子含量,提高机体免疫功能,从而改善肉鸭生长性能,降低死淘率。

This experiment was conducted to study the effects of dietary plant essential oil on growth performance,serum biochemical indexes and immune function of ducks challenged by Escherichia coli.A total of 144 one-day-old healthy male Peking ducks were selected and randomly divided into three groups with six replicates per group and eight ducks per replicate.Ducks in the control group were fed a basal diet,and others in two experimental groups were fed basal diets supplemented with 30 mg/kg virginiamycin(antibiotic group)and 200 mg/kg plant essential oil(essential oil group),respectively.On day 7,all ducks were orally taken 0.2 mL Escherichia coli O 88(3×109 CFU/mL)twice,8 hours apart.The experiment lasted for 28 days.The results showed as follows:1)compared with the control group,dietary antibiotics and plant essential oil significantly increased the body weight at 9 days of age and average daily gain during 1 to 9 days of age(P<0.05),dietary plant essential oil significantly decreased the feed to gain ratio during 1 to 9 days of age and during 1 to 28 days of age(P<0.05 or P<0.01);the mortality of ducks in antibiotic group and essential oil group decreased by 6.25 and 4.17 percentage points,respectively.2)Compared with the control group,dietary plant essential oil significantly increased the bursa of Fabricius index at 14 days of age(P<0.01),dietary antibiotics significantly increased the spleen and bursa of Fabricius indexes at 28 days of age(P<0.01).3)Compared with the control group,dietary plant essential oil significantly decreased the contents of total protein and globulin in serum at 28 days of age(P<0.05 or P<0.01).4)Compared with the control group,dietary plant essential oil significantly increased the serum immunoglobulin G(IgG)content at 9 days of age and serum immunoglobulin M(IgM)content at 9,14 and 28 days of age(P<0.05 or P<0.01);dietary antibiotics significantly increased the serum IgG content at 9 days of age and serum IgM content at 14 days of age(P<0.01).5)Compared with the control group,dietary plant essential oil significantly decreased the jejunal Toll like receptor 4(TLR4)content at 9 and 28 days of age,jejunal tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)contents at 9,14 and 28 days of age,and jejunal interleukin-6(IL-6)content at 14 days of age(P<0.05);dietary antibiotics significantly decreased the jejunal TLR4,IL-1βand IL-6 contents at 9,14 and 28 days of age and jejunal TNF-αcontents at 9 and 28 days of age(P<0.05).In conclusion,under the condition of Escherichia coli challenge,dietary plant essential oil can replace antibiotics to alleviate the inflammatory reaction of body,reduce organ damage and jejunal inflammatory cytokine contents,improve the immune function of the body,so as to improve the growth performance and reduce the mortality of ducks.