Effects of Feeding Different Postbiotics Produced by Lactobacillus plantarum on Growth Performance, Carcass Yield, Intestinal Morphology, Gut Microbiota Composition, Immune Status, and Growth Gene Expression in Broilers under Heat Stress
Effects of Feeding Different Postbiotics Produced by Lactobacillus plantarum on Growth Performance, Carcass Yield, Intestinal Morphology, Gut Microbiota Composition, Immune Status, and Growth Gene Expression in Broilers under Heat Stress
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DOI：
10.3390/ani9090644
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发表时间：
2019-09-01
期刊：
影响因子：
3
通讯作者：
Izuddin, Wan Ibrahim
中科院分区：
文献类型：
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作者：
Humam, Ali Merzza;Loh, Teck Chwen;Izuddin, Wan Ibrahim
热应激是包括马来西亚在内的湿热国家商业肉鸡生产中的一个严重问题。肉鸡暴露于热应激会影响其健康和生产力。在这种情况下，抗生素被广泛用于亚治疗水平的生长促进剂，以减少压力和传染病，以维持商业肉鸡养殖场的生产力。然而，长期以来抗生素作为生长促进剂的广泛使用导致了耐药细菌的发展以及耐药基因在生物体之间转移的可能性。近年来，植物乳杆菌产生的益生素作为饲料添加剂被广泛研究，以取代饲料中的抗生素。然而，到目前为止，还没有研究探讨益生素在热应激下肉鸡饲料中的作用。研究了热应激条件下不同益生素对肉仔鸡生长性能、胴体产量、肠道形态、肠道菌群、免疫功能以及生长激素受体（GHR）和胰岛素样生长因子1（IGF-1）基因表达的影响。将252只1日龄雄性肉鸡（Cobb 500）随机分配到相同环境控制室的笼中。在1 ~ 21日龄的初始阶段，所有鸡饲喂相同的基础日粮。在第22天，将鸡称重并随机分为6个处理组，并从11：00至14：00每天暴露于36 +/-1 ℃的循环高温3小时，直至实验结束。从第22天至第42天（育成期），对相同数量的鸟进行以下饮食之一：NC（阴性对照）基础饮食; PC（阳性对照）基础饮食+0.02%土霉素;或AA（抗坏血酸）基础饮食+0.02%抗坏血酸。其他三组（RI 11、RS 5和UL 4）为基础饮食+0.3%不同的益生素（由不同的植物乳杆菌菌株产生，并且分别定义为RI 11、RS 5和UL 4）。结果表明，与接受NC、PC和AA处理的鸡相比，饲喂RI 11饲料的鸡具有显著更高的最终体重、总增重和平均日增重。RI 11组的饲料转化率显著高于其他组。胴体参数不受postbiotic-supported饮食。与NC、PC和AA处理相比，添加益生素显著改善了十二指肠、空肠和回肠的绒毛高度。NC组十二指肠和回肠的隐窝深度显著高于其他处理组，但RI 11在十二指肠中除外，而UL 4在回肠中与NC组无差异。十二指肠和回肠的绒毛高度与隐窝深度的比值，益生素处理组和AA组显著高于PC和NC处理组。与NC和PC处理组相比，生物后RI 11组记录了显著更高的盲肠总细菌和乳酸杆菌计数以及更低的沙门氏菌计数。NC组中的双歧杆菌群显著低于其他处理组。抗生素（RI 11、RS 5和UL 4）和AA处理组的肠杆菌和E.大肠杆菌计数和盲肠pH值高于NC和PC处理组。RI 11组血浆免疫球蛋白M（IgM）水平显著高于其他处理组，RI 11组血浆免疫球蛋白G（IgG）水平显著高于NC、AA和RS 5组。血浆免疫球蛋白A（伊加）水平不受影响的postbiotic补充剂。与NC饲喂的鸡相比，饲喂益生素RI 11、RS 5和UL 4、AA和PC的鸡的肝脏GHR mRNA表达水平显著增加。与NC、PC和AA处理相比，Postbiotic RI 11导致显著更高的肝脏IGF-1 mRNA表达水平。死亡率在生物后处理组中在数值上较小，但在所有处理之间没有显著差异。综上所述，在目前研究中应用的益生素中，与NC、PC和AA相比，RI 11可用作家禽业中潜在的替代抗生素生长促进剂和抗应激治疗。
Simple Summary Heat stress is a serious issue in commercial broiler production in hot and humid countries, including Malaysia. Exposure of broilers to heat stress affects their health and productivity. In this context, antibiotics are widely used at sub-therapeutic levels as growth promoters to reduce stress and infectious diseases in order to sustain productivity in commercial broiler farms. However, the extensive use of antibiotics as growth promoters for a long time leads to the development of antibiotic-resistant bacteria and the possibility of antibiotic-resistant genes being transferred among organisms. Recently, postbiotics produced by Lactobacillus plantarum have been widely studied as a feed additive in order to replace in-feed antibiotics. However, to date, no studies have investigated the role of postbiotics in feed for broilers under heat stress. The effects of feeding different postbiotics on growth performance, carcass yield, intestinal morphology, gut microbiota, immune status, and growth hormone receptor (GHR) and insulin-like growth factor 1 (IGF-1) gene expression in broilers under heat stress were assessed in this study. A total of 252 one-day-old male broiler chicks (Cobb 500) were randomly assigned in cages in identical environmentally controlled chambers. During the starter period from 1 to 21 days, all the birds were fed the same basal diet. On day 22, the birds were weighed and randomly divided into six treatment groups and exposed to cyclic high temperature at 36 +/- 1 degrees C for 3 h per day from 11:00 to 14:00 until the end of the experiment. From day 22 to 42 (finisher period), an equal number of birds were subjected to one of the following diets: NC (negative control) basal diet; PC (positive control) basal diet + 0.02% oxytetracycline; or AA (ascorbic acid) basal diet + 0.02% ascorbic acid. The other three groups (RI11, RS5 and UL4) were basal diet + 0.3% different postbiotics (produced from different Lactobacillus plantarum strains, and defined as RI11, RS5 and UL4, respectively). The results demonstrated that birds fed RI11 diets had significantly higher final body weight, total weight gain and average daily gain than the birds that received the NC, PC and AA treatments. The feed conversion ratio was significantly higher in the RI11 group compared with the other groups. Carcass parameters were not affected by the postbiotic-supplemented diet. Postbiotic supplementation improved villi height significantly in the duodenum, jejunum and ileum compared to the NC, PC and AA treatments. The crypt depth of the duodenum and ileum was significantly higher in NC group compared to other treatment groups except RI11 in duodenum, and UL4 in ileum was not different with NC groups. The villus height to crypt depth ratio of duodenum and ileum was significantly higher for the postbiotic treatment groups and AA than the PC and NC treatment groups. The postbiotic RI11 group recorded significantly higher caecum total bacteria and Lactobacillus count and lower Salmonella count compared to the NC and PC treatment groups. The Bifidobacterium population in the NC group was significantly lower compared to the other treatment groups. The postbiotic (RI11, RS5 and UL4) and AA treatment groups showed lower Enterobacteriaceae and E. coli counts and caecal pH than the NC and PC treatment groups. The plasma immunoglobulin M (IgM) level was significantly higher in the birds receiving postbiotic RI11 than those receiving other treatments.The plasma immunoglobulin G (IgG) level was higher in the RI11 treatment group than in the NC, AA and RS5 groups. The plasma immunoglobulin A (IgA) level was not affected by postbiotic supplements. The hepatic GHR mRNA expression level was significantly increased in birds fed postbiotics RI11, RS5 and UL4, AA and PC compared to the NC-fed birds. Postbiotic RI11 led to significantly higher hepatic IGF-1 mRNA expression level compared to the NC, PC, and AA treatments. Mortality was numerically lesser in the postbiotic treatment groups, but not significantly different among all the treatments. In conclusion, among the postbiotics applied in the current study as compared with NC, PC and AA, RI11 could be used as a potential alternative antibiotic growth promoter and anti-stress treatment in the poultry industry.