枯草芽孢杆菌对球虫和产气荚膜梭菌混合攻毒肉鸡生长性能及肠道健康的影响

Effects of Bacillus subtilis on Growth Performance and Intestinal Health of Broilers Attacked by Coccidia and Clostridium perfringens

本试验旨在研究枯草芽孢杆菌对球虫和产气荚膜梭菌混合攻毒肉鸡生长性能及肠道健康的影响。选用1日龄雄性爱拔益加肉鸡720只,随机分成8个组,每组6个重复,每个重复15只。试验采用2×4因子设计,在攻毒与不攻毒的基础下,分别设置4个处理,分别饲喂基础饲粮、基础饲粮+300 mg/kg枯草芽孢杆菌、基础饲粮+500 mg/kg枯草芽孢杆菌、基础饲粮+12 mg/kg恩拉霉素。攻毒组肉鸡分别于14日龄攻毒球虫、19~21日龄攻毒产气荚膜梭菌。肉鸡笼养,自由采食和饮水,试验期为42 d。结果表明:1)攻毒显著提高了肉鸡22~42日龄的料重比(P<0.05),显著提高了肉鸡28、35日龄血清二胺氧化酶活性及35日龄血清脂多糖含量(P<0.05),显著降低了肉鸡28、35日龄空肠和回肠绒毛高度、绒毛高度/隐窝深度(P<0.05),显著提高了肉鸡28、35日龄空肠和回肠隐窝深度(P<0.05),显著提高了肉鸡28、35日龄空肠肿瘤坏死因子-α(TNF-α)、干扰素-γ(IFN-γ)、核转录因子-κB(NF-κB)、白细胞介素-6 (IL-6)mRNA表达量(P<0.05),显著提高了肉鸡28日龄空肠白细胞介素-12(IL-12) mRNA表达量(P<0.05)。2)与基础饲粮、添加500 mg/kg枯草芽孢杆菌相比,添加300 mg/kg枯草芽孢杆菌显著提高了肉鸡1~21日龄、22~42日龄的平均日增重、末重(P<0.05),显著降低了肉鸡22~42日龄的料重比(P<0.05)。与基础饲粮相比,添加500 mg/kg枯草芽孢杆菌显著降低了肉鸡28日龄血清脂多糖含量(P<0.05),添加300 mg/kg枯草芽孢杆菌显著提高了肉鸡28、35日龄的回肠的绒毛高度(P<0.05),添加12 mg/kg恩拉霉素、300 mg/kg枯草芽孢杆菌显著降低了肉鸡35日龄的空肠TNF-α、NF-κB和IL-6 mRNA表达量(P<0.05)。3)攻毒与饲粮对肉鸡22~42日龄料重比、35日龄肠道形态(除空肠隐窝深度)、28日龄空肠NF-κB和IL-6 mRNA表达量以及35日龄空肠TNF-α、NF-κB和IL-6 mRNA表达量的影响存在交互效应(P<0.05)。由此可见,枯草芽孢杆菌能缓解球虫和产气荚膜梭菌混合攻毒对肉鸡造成的负面影响,一定程度上提长生产性能、改善肠道健康,且添加300 mg/kg枯草芽孢杆菌的效果优于添加500 mg/kg。

This experiment was conducted to investigate the effects of Bacillus subtilis on growth performance and intestinal health of broilers attacked by coccidia and Clostridium perfringens.A total of 720 one-day-old Arbor Acres male broilers were selected and randomly divided into 8 groups with 6 replicates in each group and15 birds in each replicate.The experiment was set up in a 2×4 factorial design with four treatments on the basis of attack and no attack,which feeding the basal diet,basal diet + 300 mg/kg Bacillus subtilis,basal diet +500 mg/kg Bacillus subtilis and basal diet+12 mg/kg enramycin,respectively.Broilers in the attack groups were attacked by coccidia at 14 days of age and attacked by Clostridium perfringens at 19 to 21 days of age.Broilers were caged and fed and watered ad libitum for a trial period of 42 days.The results were as follows:1)the attack significantly increased the feed to gain ratio of broilers during 22 to 42 days of age(P<0.05),significantly increased the serum diamine oxidase activity at 28 and 35 days of age and serum lipopolysaccharide content at 35 days of age of broilers(P<0.05),significantly decreased the villus height and villus height/crypt depth in jejunum and ileum at 28 and 35 days of age of broilers(P<0.05),significantly increased the crypt depth in jejunum and ileum at 28 and 35 days of age of broilers(P<0.05),significantly increased the mRNA relative expression levels of tumor necrosis factor-α(TNF-α),interferon-γ(IFN-γ),nuclear transcription factor-κB(NF-κB)and interleukin-6(IL-6)in jejunum at 28 and 35 days of age of broilers(P<0.05),and significantly increased the mRNA relative expression level of interleukin-12(IL-12)in jejunum at28 days of age of broilers(P<0.05).2)Compared with the basal diet and addition of 500 mg/kg Bacillus subtilis,the addition of 300 mg/kg Bacillus subtilis significantly increased the average daily gain and final body weight of broilers during 1 to 21 days of age and 22 to 42 days of age(P<0.05),and significantly decreased the feed to gain ratio of broilers during 22 to 42 days of age(P<0.05).Compared with the basal diet,the addition of 500 mg/kg Bacillus subtilis significantly decreased the serum lipopolysaccharide content at 28days of age of broilers(P<0.05),the addition of 300 mg/kg Bacillus subtilis significantly increased the ileum villi height at 28 and 35 days of age of broilers(P < 0.05),and the addition of 12 mg/kg enramycin and300 mg/kg Bacillus subtilis significantly increased the mRNA expression levels of TNF-α,NF-κB and IL-6 in jejunum at 35 days of age of broilers(P<0.05).3)There were interactive effects on of attack and diet on the feed to gain ratio of broilers during 22 to 42 days of age,the intestinal morphology(except jejunal crypt depth)at 35 days of age,the mRNA relative expression levels of NF-κB and IL-6 in jejunum at 28 days of age,and the mRNA relative expression levels of TNF-α,NF-κB and IL-6 in jejunum at 35 days of age(P<0.05).In conclusion,the Bacillus subtilis can alleviate the negative impact of broilers attacked by coccidia and Clostridium perfringens,improve the growth performance and intestinal health to a certain extent,and the addition of 300 mg/kg Bacillus subtilis is better than the addition of 500 mg/kg.[Chinese Journal of Animal Nutrition,2022,34(11):7082-7093]