Effect of organic acids or probiotics alone or in combination on growth performance,nutrient digestibility,enzyme activities,intestinal morphology and gut microflora in broiler chickens

A feeding trial was conducted to determine the effect of organic acids or probiotics alone or in combination on growth performance, nutrient digestibility, enzyme activity, intestinal morphology and gut microflora in broiler chickens (Ross308). A completely randomized design was used, with 1,440 broiler chicks across four treatments and five replications of 72 chicks each. The chicks in the control treatment were fed on a control diet (CD), whereas for the other treatment groups, the CD was supplemented with 0.2 g/kg organic acids (CDOA), probiotics (CDP) or a combination of organic acids and probiotics (CDOAP). All the chicks were fed ad libitum during the feeding trial throughout 35 days. A total of 20 chicks were randomly allotted to individual metabolic cages to measure the nutrient digestibility (35–42 days) and the digestive enzyme activities (42 days). The intestinal morphology and gut microflora of 80 chicks were examined at the end of experiment. There were no significant (p > .05) differences in the feed intake, body weight gain or feed conversion ratio of the chicks across the four dietary treatments. The crude fibre digestibility was significantly increased in chicks fed on CDOA or CDOAP relative to CD (p < .05). Nutrient utilization, in terms of digestive enzyme activities and excreta thermal property, was unchanged by any supplementation. The chicks fed on the CDOAP had significantly higher duodenal villi height and crypt depth than the chicks fed on CDOA (p < .05). This dietary treatment dramatically improved gut microflora by decreasing the population of Escherichia coli and increasing the Lactobacillus spp.:E. coli ratio. Based on our investigations, supplementation of organic acids and probiotics in chick diets can increase the ability to digest crude fibre and villus height and decrease intestinal E. coli without impairing growth performance.     

The effects of benzoic acid supplementation on the performance of broiler chickens

To determine the efficiency of benzoic acid, a feeding experiment was carried out with 240 one‐day old ROSS 308 cockerels. Birds were divided into three dietary treatments: I (C) – no additives, II (B1) – 0.1% inclusion of benzoic acid, III (B2) – the inclusion of 0.2% benzoic acid. The performance results were similar in birds fed the control diet and the diet with 0.1% of benzoic acid. The dietary inclusion of benzoic acid at 0.2% depressed the growth of broiler chickens (p < 0.05). The dry matter of the digesta increased in the crop and caeca after benzoic acid supplementation. The pH of the caecal contents decreased following benzoic acid supplementation and was the lowest in the B2 group. No differences were found in the pH of the crop, ileal, gizzard digesta and rectum content. Lactic acid bacteria populations were the lowest in the caeca of the B1 group (p < 0.05). Coliform bacteria decreased in the caeca contents following increased benzoic acid supplementation.     

枯草芽孢杆菌对肉鸡肠道消化酶活性、黏膜结构及肠道菌群组成的影响

将216羽1日龄罗斯308肉鸡随机分成对照组和处理组,每组设3个重复,每个重复36羽。对照组饲喂基础日粮,处理组饲喂基础日粮加枯草芽孢杆菌制剂。饲养期42d。结果显示：与对照组相比,处理组肉鸡十二指肠内容物中胰蛋白酶、淀粉酶、脂肪酶和总蛋白水解酶的活性均显著提高（P〈0.05）;十二指肠、空肠和回肠绒毛高度显著增加（P〈0.05）,绒毛高度和隐窝深度的比值（VH/CD）显著升高（P〈0.05）;空肠和盲肠内容物中乳酸菌数量显著增加（P〈0.05）,大肠杆菌数量显著降低（P〈0.05）。结果表明,肉鸡日粮中添加适量的枯草芽孢杆菌能显著提高肉鸡消化酶活性,改善肉鸡肠黏膜结构及菌群组成,从而提高肉鸡的生长性能。     

Ileal MUC2 gene expression and microbial population,but not growth performance and immune response,are influenced by in ovo injection of probiotics in broiler chickens

1. The objective of present study was to evaluate the effects of intra-amniotic injection of different probiotic strains (Bacillus subtilis, Enterococcus faecium and Pediococcus acidilactici) on the intestinal MUC2 gene expression, microbial population, growth performance and immune response in broiler chicken.

2. In a completely randomised design, different probiotic strains were injected into the amniotic fluid of the 480 live embryos (d 18 of incubation), with 4 treatments and 5 replicates. Ileal MUC2 gene expression, microbial profile, growth performance and immune response were determined.

3. Injection of probiotic strains, especially B. subtilis, had significant effect on expression of the MUC2 on d 21 of incubation and d 3 post-hatch, but not on d 19 of incubation.

4. Injection of the probiotic strains decreased significantly the Escherichia coli population and increased the lactic acid bacteria population during the first week post-hatch.

5. Inoculation of probiotics had no significant effect on antibody titres against Newcastle disease virus, antibody titres against sheep red blood cell and cell-mediated immune response of chickens compared to control.

6. In ovo injection of the probiotic strains had no significant effect on growth performance of broiler chickens.

7. It was concluded that injection of probiotic bacteria especially B. subtilis into the amniotic fluid has a beneficial effect on ileal MUC2 gene expression and bacteria population during the first week post-hatch, but has no effect on growth performance and immune response in broiler chickens.     

The effect of dietary lysozyme with EDTA on growth performance and intestinal microbiota of broiler chickens in each period of the growth cycle

Lysozyme is a potential replacement for antibiotics in the poultry industry. Two trials were conducted using new or used litter to determine the effect of 100 ppm lysozyme in feed on growth performance and intestinal microbiota of broiler chickens in each period of the growth cycle. The new litter trial and used litter trial were each analyzed as a one-way analysis of variance with length of time in which 100 ppm lysozyme was fed to the birds as the main factor (no lysozyme d zero to 35; positive lysozyme d zero to 4; positive lysozyme d 5 to 14; positive lysozyme d 15 to 24; positive lysozyme d 25 to 35; positive lysozyme d zero to 35; positive virginiamycin d zero to 35). Effects of lysozyme were not detected under clean conditions (P > 0.05). When used litter was provided, growth performance was not improved by lysozyme (P > 0.05). However, feeding lysozyme to birds from d 5 to 14 and throughout the trial reduced the number of E. coli in the ileum compared with feeding virginiamycin (positive lysozyme d 5 to 14 and zero to 35, and virginiamycin d zero to 35: 1.7 × 10⁴ cfu g⁻¹, 1.9 × 10⁴ cfu g⁻¹ and 9.3 × 10⁴ cfu g⁻¹, respectively) to birds (P < 0.05). Dietary lysozyme at 100 ppm can change intestinal microbiota of broiler chickens.     

Effects of supplementing freeze-dried Mitsuokella jalaludinii phytase on the growth performance and gut microbial diversity of broiler chickens

Inclusion of phytase in animal feedstuff is a common practice to enhance nutrients availability. However, little is known about the effects of phytase supplementation on the microbial ecology of the gastrointestinal tract. In this study, freeze-dried Mitsuokella jalaludinii phytase (MJ) was evaluated in a feeding trial with broilers fed a low available phosphorus (aP) diet. A total of 180 male broiler chicks (day-old Cobb) were assigned into three dietary treatments: Control fed with 0.4% (w/w) of available phosphorus (aP); Group T1 fed low aP [0.2% (w/w)] supplemented with MJ; and T2 fed low aP and deactivated MJ. The source of readily available P, dicalcium phosphate (DCP), was removed from low aP diet, whereby additional limestone was provided to replace the amount of Ca normally found in DCP. For each treatment, 4 replicate pens were used, where each pen consisted of 15 animals. The animals' energy intake and caecal bacterial community were monitored weekly for up to 3 weeks. The apparent metabolizable energy (AME) and apparent digestibility of dry matter (ADDM) of broilers fed with different diets were determined. In addition, the caecal microbial diversities of broilers were assessed using high-throughput next-generation sequencing targeting the V3-V4 region of bacterial 16S rRNA. The results showed that broilers fed with T1 diet have better feed conversion ratio (FCR) when compared to the Control (p < .05) and T2 diets (p < .05), demonstrating the efficiency of MJ as a supplement to low aP diet. Nevertheless, MJ did not significantly affect the microbial population and diversity in broilers' caeca, which mainly consists of members from Bacteroidetes, Firmicutes, and Proteobacteria. Regardless, significant variations in the caecal bacterial composition were observed over time, probably due to succession as the broilers aged. This is the first reported study on the effect of MJ on the microbial diversity of broiler's caeca.     

Dietary supplementation of phenyllactic acid on growth performance,immune response,cecal microbial population,and meat quality attributes of broiler chickens

A total of 750 one-day-old male broiler chicks were randomly fed 5 dietary treatments with 5 replicate pens per treatment. The 5 dietary treatments fed for 42 d were a corn-soybean meal basal diet without antibiotic (control); a mixture of 10 ppm of avilamycin + 60 ppm of salinomycin as antibiotic growth promoters (AGP); 0.1% phenyllactic acid (PLA); 0.2% PLA; and 0.4% PLA. The BW gain and FE were significantly improved in AGP and PLA groups compared with control group. The white blood cells and heterophil counts were significantly higher in the PLA-supplemented groups compared with AGP and control groups, but the heterophil-to-lymphocyte ratio was lower in the control group than other groups. The plasma IgY concentration was significantly increased in birds fed PLA-supplemented diets, but the plasma IgA and IgM concentrations were not different among the treatment groups. In addition, the antibody titer against Newcastle disease virus was significantly higher in PLA-treated compared with control and AGP-treated groups. Neither PLA nor AGP treatments affected the cecal aerobes andSalmonella content; however, cecalLactobacillus population increased in chickens fed 0.1% PLA, and total coliform bacteria population significantly decreased in chickens fed various levels of PLA and AGP. Dietary supplementation of PLA did not affect the pH, lightness, and redness of breast meat, but the water-holding capacity and shear force value increased and the yellowness decreased significantly when birds were fed PLA. It was concluded that dietary supplementation of 0.1 and 0.2% PLA improves BW gain and FE of broiler chickens. In addition, PLA supplementation increases the immune characteristics and the number of lactic acid bacteria, decreases the number of coliform bacteria, and improves the meat quality attributes of broiler chickens. Thus, dietary PLA could be a viable alternative to antibiotics in broiler diets.     

谷氨酸锌对肉仔鸡生长性能、血清含锌酶活性及免疫器官指数的影响

本试验旨在研究谷氨酸螯合锌(zinc glutamine,Glu-Zn)对肉仔鸡生长性能、血清含锌酶活性、免疫器官指数的影响。选用240只7日龄商品代AA肉用仔鸡,随机分成6个处理。1组为对照组饲喂含80mgZnSO4·H2O形式的Zn的基础日粮,其余5组分别在基础日粮中添加20、40、60、80mg/kg和100mg/kg谷氨酸螯合锌形式的Zn。饲养期为35d。结果表明:试验各周及全期,随着日粮中谷氨酸螯合锌水平的增加,肉仔鸡日增重和饲料转化效率均得到改善,同时,40mg/kg谷氨酸螯合锌组显著提高了试验全期的平均日增重(P0.05);血清碱性磷酸酶活性随着日粮锌水平的增加先上升,而后又下降,在锌添加水平为60mg/kg时取得最大值;谷氨酸螯合锌组在胸腺指数、脾脏指数上,明显优于对照组,且存在显著差异(P0.05),而法氏囊指数并不敏感。从本试验各项指标和经济效益综合分析,建议肉仔鸡饲料中添加60mg/kg的谷氨酸螯合锌。     

Effects of dietary inclusion levels of palm oil on growth performance,antioxidative status and serum cytokines of broiler chickens

This study was conducted to investigate the effects of dietary palm oil inclusion levels on growth performance, serum antioxidative status and cytokines in Sanhuang broiler chickens. A total of 208 one‐day‐old female Sanhuang chickens were randomly allocated to four treatment groups with four replicates per group and of 13 birds each for a 42‐day feeding trial. Dietary treatments were basal diet without palm oil (control) and diets containing 2%, 4% or 6% palm oil. During days 22 to 42 and the overall experimental period, chickens fed diets supplemented with 4% and 6% palm oil had a lower average daily feed intake (ADFI) (p = 0.019) and feed to gain ratio (F/G) (p = 0.031). Average daily gain (ADG) tended to be higher (p = 0.089) for palm oil inclusion treatments compared with the control treatment from days 1 to 42. Dietary 2% and 4% palm oil treatments significantly lowed serum malondialdehyde concentration on day 21 when compared to the control and 6% palm oil treatments (p = 0.027). Dietary 6% palm oil treatment significantly reduced the catalase (CAT) activity (p = 0.018) and total antioxidant capacity (T‐AOC) (p = 0.027) in serum in comparison with the control treatment on day 21. No significant differences were observed in superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activities in serum among dietary treatments on day 21. There were no significant differences in T‐AOC, CAT, SOD and GSH‐Px activities among dietary treatments on day 42. Dietary inclusion of 4% and 6% palm oil significantly increased (p = 0.01) serum interleukin‐1β (IL‐1β) content, but improved transforming growth factor‐β (TGF‐β) content in serum on both days 21 and 42 (p = 0.032 and 0.022 respectively) as well as IL‐10 content on day 42 (p = 0.022) when compared with the control treatment. Furthermore, dietary inclusion of 6% palm oil significantly reduced tumour necrosis factor‐α (TNF‐α) content on days 21 and 42 (p = 0.021 and 0.001 respectively) compared with the control treatment. These results suggest that dietary inclusion of 4% and 6% palm oil could improve the growth performance, modulate the balance between pro‐ and anti‐inflammatory cytokines, and show limited effect on antioxidative status in Sanhuang broiler chickens.     

复合微生态制剂对肉仔鸡生长性能、肠道菌群和免疫功能的影响

为研究探讨肉仔鸡日粮中添加不同剂量的复合微生态制剂对肉仔鸡生长性能、肠道菌群和免疫功能的影响,以期为复合微生态制剂的临床应用提供参考依据,将150只AA白羽肉仔鸡随机分成5个处理组(对照组、抗生素组、复合微生态制剂Ⅰ组、复合微生态制剂Ⅱ组、复合微生态制剂Ⅲ组),对照组饲喂基础日粮,抗生素组在基础日粮中添加0.05%的肉鸡饲用金霉素,复合微生态制剂Ⅰ、Ⅱ和Ⅲ组分别在基础日粮中添加0.05%、0.1%、0.2%的复合微生态制剂,测定平均日增重、平均日采食量、料重比、大肠杆菌数、沙门氏菌数、双歧杆菌数、乳酸杆菌数、胸腺指数、法氏囊指数、IgG含量、IgA含量、IgM含量等指标。结果显示,与对照组相比,复合微生态制剂Ⅱ组、Ⅲ组可显著增加平均日采食量、平均日增重、乳酸杆菌数、双歧杆菌数、胸腺指数、脾脏指数、法氏囊指数、IgA含量和IgG含量(P<0.05),显著降低料重比、大肠杆菌和沙门菌数(P<0.05)。与抗生素组相比,复合微生态制剂Ⅱ组、Ⅲ组可显著增加乳酸杆菌数、双歧杆菌数、胸腺指数、脾脏指数、法氏囊指数、IgA含量和IgG含量(P<0.05),显著降低料重比、大肠杆菌和沙门菌数(P<0.05)。表明肉仔鸡饲料中添加0.1%、0.2%的复合微生态制剂可显著改善提高肉仔鸡的生长性能、肠道菌群和免疫功能,其在改善肠道菌群和免疫功能方面的作用效果显著优于抗生素。     

A deficient or an excess of dietary threonine level affects intestinal mucosal integrity and barrier function in broiler chickens

The aim of this study was to investigate the effects of deficient or excess of dietary threonine (Thr) levels on intestinal integrity and barrier function of broilers. A total of 432 1‐day‐old commercial broilers (Arbor Acre) were assigned to four experiment groups consisting of six replicates of 18 birds. The treatments were designed as follows: 85%, 100%, 125% and 150% of NRC (Nutrient requirements of poultry (9th edn). Washington, DC: The National Academies Press, 1994) recommendations. The results indicated that expressions of jejunal and ileal secretory immunoglobulin A (sIgA) mRNA were increased linearly or quadratically by increasing Thr (p < .05), and the highest sIgA mRNA abundance was obtained in 125% Thr level. Likewise, the intestinal sIgA content showed similar increasing trend with the intestinal sIgA gene expression in this instance. The high level of Thr inclusion upregulated mucin 2 (MUC2) mRNA expression in the jejunum and ileum (p < .05). In addition, on day 21, the expression levels of jejunal zonula occludens‐2 (ZO‐2) and ileal zonula occludens‐1 (ZO‐1) decreased then increased with increasing Thr level (p < .05), whereas, the mRNA expressions of occludin in the jejunum and ileum had no significant difference amongst groups (p >.05). On day 42, Thr treatments did not affect the mRNA abundance of measured genes in the jejunum and ileum (p > .05). These findings suggested that Thr might be a nutrient immunomodulator that affects intestinal barrier function, moreover, 125% of the NRC (1994) recommendations Thr level was optimum.     

Effects of chestnut tannins on intestinal morphology,barrier function,pro‐inflammatory cytokine expression,microflora and antioxidant capacity in heat‐stressed broilers

A study was conducted to evaluate the effects of chestnut tannins (CT) on intestinal morphology, barrier function, pro‐inflammatory cytokine expression, microflora and antioxidant capacity in heat‐stressed broilers. Four hundred 28‐day‐old male Ross 308 broilers were randomly assigned into four groups, with 10 replicates per group and 10 broilers per replicate. The broilers in the normal (NOR) group were kept at 22 ± 1°C and fed the basal diet, and each of the other three groups were treated with cyclic heat (33 ± 1°C from 0800 to 1800 and 22 ± 1°C from 1800 to 0800) and fed the basal diet with 0 (HT), 1 (CT1) or 2 (CT2) g of CT/kg of diet. The experiment lasted for 14 days. Compared with the HT group, broilers in the NOR and CT2 groups had higher (p < .05) average daily gain and villus height in the jejunum and lower serum d ‐lactate (p < .001) and diamine oxidase (p < .01) levels. The addition of 2 g CT/kg of diet increased the total antioxidant capacity (p < .001) and superoxide dismutase activities (p < .05) and zonula occludens‐1 mRNA expression level (p < .05) and decreased the malondialdehyde concentration (p < .01) and mRNA expression levels of interleukin‐6 (p < .001) and nuclear factor kappa B (p < .001) in the jejunal mucosa of heat‐stressed broilers. The populations of Escherichia coli and Clostridium in the jejunum (p < .01) and caecum (p < .05) of broilers in the HT group were higher than those in the NOR and CT2 groups. In conclusion, the addition of 2 g CT/kg of diet seemed to be a feasible means of alleviating the negative effects of heat stress on the growth performance and intestinal function of broilers.     

抗菌肽高表达量黄粉虫对肉鸡生长性能、肠道菌群和小肠绒毛形态的影响

为探讨抗菌肽高表达量黄粉虫对肉鸡生长性能、肠道菌群和小肠绒毛形态的影响。试验以玉米和豆粕为主要原料配制饲粮,试验采用单因子随机区组设计,选择1日龄雌雄各半、体质量相近、健康的爱拔益加（AA）肉鸡300只,测体质量后随机分为3个组,分别为对照组、黄粉虫未诱导组和黄粉虫诱导组,每组5个重复,每个重复20只鸡。对照组饲喂基础日粮,未诱导组和诱导组分别用未诱导和诱导的2%黄粉虫粉等量替代基础日粮中的鱼粉。试验期42d。结果显示,各组肉鸡的日采食量差异均不显著（P=0.559）,黄粉虫诱导组日增重极显著高于对照组和黄粉虫未诱导组（P=0.005）,而料肉比极显著低于对照组和黄粉虫未诱导组（P〈0.000 1）。黄粉虫诱导组大肠杆菌数量极显著低于对照组和黄粉虫未诱导组（P〈0.000 1）,各组肉鸡乳酸杆菌数量在21目龄差异不显著（P=0.191）,42日龄差异显著（P=0.034）。添加抗菌肽高表达量的黄粉虫极显著提高十二指肠、空肠和回肠小肠绒毛的长度（P〈0.000 1）和绒毛长度与隐窝深度的比值（P〈0.000 1）,各组肉鸡的隐窝深度差异不显著,但呈诱导组〈未诱导组〈对照组的趋势。结果表明,抗菌肽高表达量黄粉虫能够提高肉鸡的生长性能,降低肠道中大肠杆菌数量,促进肠道中乳酸杆菌繁殖,改善小肠绒毛形态。     

Evaluation of Aloe vera and synbiotic as antibiotic growth promoter substitutions on performance,gut morphology,immune responses and blood constitutes of broiler chickens

This study was performed to investigate the effect of dietary supplementation with Aloe vera (AV) powder and synbiotic as growth promoter agents on performance, gut morphology, immune responses, hematology and serum biochemistry in broilers. A total of 240‐day‐old male broiler chicks (Ross 308) were randomly assigned to six treatments with four replicates. Birds were offered either a corn‐soybean meal basal diet (control) or the basal diet supplemented with 200 mg/kg virginiamycin (VM), 1 g/kg synbiotic (Syn), 2.5 g/kg AV (AV1), 5.0 g/kg AV (AV2) or 7.5 g/kg AV (AV3). Chickens fed any of the diets, except diet AV1, exhibited better feed conversion ratios at the 14–28 day period and higher average daily gain and duodenal villus height/crypt depth ratio at 42 days than those fed the control diet. Synbiotic supplementation caused a marked increase in the serum antibody titer against infectious bursal disease and infectious bronchitis vaccines. Feeding diet AV3 significantly increased red blood cell count and hemoglobin concentration, and decreased serum triglyceride level compared to the control group. The results suggested that dietary inclusion of 5 and 7.5 g/kg AV, similar with synbiotic supplementation, can be applied as effective alternatives to in‐feed antibiotics for broiler diets.