Effects of dietary fiber and threonine on performance,intestinal morphology and immune responses in broiler chickens

The present experiment was conducted to investigate the effects of fiber and threonine (Thr) on growth performance, intestinal morphology and immune responses of broiler chickens. A total of 420 one-day-old mixed sex broiler chicks (Ross 308) were randomly divided into 6 experimental diets and 5 replicates of 14 chicks based on a factorial arrangement (2 × 3) from 1 to 42 d of age. Experimental factors included dietary supplemental fiber type (no supplemental fiber [NSF], 30 g/kg sugar beet pulp [SBP] or 30 g/kg rice hull [RH]) and Thr inclusion level (100% or 110% of Thr requirement recommended by breeder company [Ross 308]). Growth performance of broilers was assayed at different periods of the experiment. Intestinal morphometric features were measured at 21 d of age. Antibody titer against sheep red blood cells (SRBC), Newcastle and influenza disease viruses were measured on d 30 of trial. Dietary inclusion of SBP and RH significantly decreased feed intake and weight gain during the entire rearing period (P < 0.05). Interaction of fiber and Thr had no beneficial effects on the performance of chickens across the entire rearing phase. Dietary supplementation of 110% Thr required level improved jejunal morphometric features (P < 0.05), whereas its inclusion with fibrous materials failed to show the same effects. Dietary supplemental Thr together with SBP significantly increased antibody production against SRBC (P < 0.05). In conclusion, although supplemental 30 g/kg fibrous materials impaired growth performance, inclusion of SBP along with 110% Thr level improved the humoral immunity in broiler chickens.     

Probiotic Paenibacillus polymyxa 10 and Lactobacillus plantarum 16 enhance growth performance of broilers by improving the intestinal health

With the ever-growing strict prohibitions on antibiotic growth promoters (AGP) in animal production, in-feed probiotics are becoming attractive alternatives to antibiotics in the poultry industry. To investigate the effects of Paenibacillus polymyxa 10 and Lactobacillus plantarum 16 on the growth performance and intestinal health of broilers, 540 male Cobb 500 broilers of 1 d old were randomly divided into 3 groups with 6 replicates per group and 30 chicks per replicate. Broilers were fed with either a basal diet or basal diets supplemented with 1 × 10⁸ colony-forming units (CFU)/kg P. polymyxa 10 (BSC10) or L. plantarum 16 (Lac16) for 42 d. Results showed that Lac16 treatment improved (P < 0.05) the growth performance (body weight and feed conversion) of broilers at the starter phase, while BSC10 treatment slightly improved (P > 0.05) the growth performance of the starter phase broilers. The increased villus height (P < 0.05) at d 14, 21 and 42 and villus height to crypt depth ratio (P < 0.05) at d 14 and 21 were observed in the ileum of the 2 probiotic groups. Besides, transmission electron microscopy results showed that the 2 probiotics enhanced the intestinal epithelial barrier. Both probiotic treatments up-regulated (P < 0.05) the mRNA expression of fatty acid binding protein 1 (FABP1) and sodium-dependent glucose transporters-1 (SGLT-1) in the ileal mucosa of broilers at d 21. In addition, BSC10 and Lac16 treatments significantly (P < 0.05) increased the relative abundance of short-chain fatty acids-producing bacteria, such as Butyricicoccus pullicaecorum, Faecalibacterium prausnitzii, Lachnospira and Coprococcu, and significantly (P < 0.05) decreased the relative abundance of enteric pathogens (Escherichia coli, Bacteroides fragilis and Shigella sonnei). Furthermore, the 2 probiotic treatments also increased the positive connection among the intestinal microbes and the carbohydrate metabolism-related pathways of the intestinal bacteria (P < 0.05), with decreasing (P < 0.05) nucleotides biosynthesis-related pathways of the intestinal bacteria. Overall, these results suggest that the 2 probiotics, especially Lac16, have a potential beneficial effect on the growth performance and intestinal health of starter phase broilers.     

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。     

Dietary chenodeoxycholic acid improves growth performance and intestinal health by altering serum metabolic profiles and gut bacteria in weaned piglets

Nutritional diarrhea and subsequent performance degradation in weaned piglets are major challenges for the pig industry. Bile acids (BA) can be added to the diet as emulsifiers. This experiment was conducted to investigate the effects of chenodeoxycholic acid (CDCA), a major primary BA, on growth performance, serum metabolic profiles and gut health in weaned piglets. A total of 72 healthy weaned piglets were randomly assigned to the control (CON) and the CDCA groups, which were feed a basal diet and the basal diet supplemented with 200 mg/kg CDCA for 30 d, respectively. Our results demonstrated that CDCA significantly increased final BW and average daily gain (ADG), decreased feed-to-gain (F:G) ratio and tended to reduce diarrhea incidence. In addition, CDCA increased the villus height-to-crypt depth (V:C) ratio, elevated goblet cell numbers and the expression of tight junction proteins, suggesting the enhancement of intestinal barrier function. As an emulsifier, CDCA increased jejunal lipase activity and the mRNA expression of pancreatic lipases. CDCA supplementation also altered the serum metabolic profiles, including increasing the levels of indole 3-acetic acid, N′-formylkynurenine and theobromine that were beneficial for gut health. Moreover, the relative abundance of 2 beneficial gut bacteria, Prevotella9 and PrevotellaceaeTCG-001, were increased, whereas the relative abundance of a harmful bacteria, Dorea, was decreased in the gut of weaned piglets supplemented with CDCA. Importantly, the altered serum metabolic profiles showed a strong correlation with the changed gut bacteria. In conclusion, CDCA improved the growth performance of weaned piglets by improving intestinal morphology and barrier function, and enhancing lipid digestion, accompanied by alterations of serum metabolic profiles, and changes in relative abundance of certain gut bacteria.     

Dietary supplementation with acidifiers improves the growth performance,meat quality and intestinal health of broiler chickens

This experiment was conducted to study the effects of dietary supplementation with acidifiers on the growth performance, meat quality, and intestinal health of broiler chickens. A total of 648 male Arbor Acres broiler chickens at 1 d old were randomly divided into 6 groups, and each group consisted of 6 replicates with 18 broilers per replicate. The dietary treatments were as follows: negative control (NC, the basal diet), NC + antibiotic (enramycin, 8 mg/kg, positive control [PC]), NC + phosphoric acid (PA, 0.1, 0.2, and 0.3 g/kg), and NC + lactic acid (LA, 0.3 g/kg). The feeding trial lasted for 42 d. The results showed that the feed-to-gain ratio of the NC + acidifier groups was lower than that of the NC and PC groups from 1 to 42 d (P < 0.05). Compared with the values in the NC group, the pH of breast muscle was significantly higher in the NC + PA (0.2 g/kg) and LA (0.3 g/kg) groups (P < 0.05), and the cooking loss was lower in the breast muscle of the NC + PA (0.1 g/kg) and LA (0.3 g/kg) groups (P < 0.05). In addition, the shear force of the breast muscle and thigh muscle and the pH value in the crop, gizzard and duodenum of the antibiotic and acidifier groups were significantly decreased (P < 0.05). Moreover, the trypsin, chymotrypsin, and lipase activities of the duodenum in the NC + PA (0.2 and 0.3 g/kg) groups, as well as the villus height-to-crypt depth (VH:CD) ratio of the duodenum in the NC + PA (0.1 g/kg) group was significantly greater (P < 0.05) compared with those in the NC group. Meanwhile, the number of total aerobic bacteria, Escherichia coli and Salmonella in the cecum of the NC + PA (0.1 g/kg) and LA (0.3 g/kg) groups were decreased (P < 0.05). Collectively, diet supplementation with acidifiers could improve the growth performance, meat quality, and intestinal health of broilers, in which the effects of PA (0.1 g/kg and 0.2 g/kg) are better than the other supplementations.     

苯甲酸和精油对肉鸡生长性能、抗氧化状态和肠道微生物群的影响

本研究开展了3个饲养试验,旨在探讨苯甲酸和精油单独或联合使用对肉鸡生长性能、肠道微生物含量及肝脏抗氧化性能的影响.试验1和2均选择1日龄肉鸡450只,分为3组,每组5个重复,每个重复30只.对照组均饲喂相同的基础日粮,试验1处理组肉鸡分别饲喂基础日粮添加1.5和3?g/kg苯甲酸,试验2处理组肉鸡分别饲喂日粮添加2和4...     

Dietary ferulic acid and vanillic acid on inflammation,gut barrier function and growth performance in lipopolysaccharide-challenged piglets

Ferulic acid(FA) and vanillic acid(VA) are considered as major phenolic metabolites of cyanidin 3-glucoside, a polyphenol that widely exists in plants that possess a protective effect against oxidative stress and inflammation in our previous study. This study aimed to investigate the effect of FA and VA on inflammation, gut barrier function, and growth performance in a weaned piglet model challenged with lipopolysaccharide(LPS). Thirty-six piglets(PIC 337 × C48, 28 d of age) were randomly alloca...     

Source of fiber influences growth,immune responses,gut barrier function and microbiota in weaned piglets fed antibiotic-free diets

This study examined the impacts of different fiber sources on growth, immune status and gut health in weaned piglets fed antibiotic-free diets. Sixty piglets (BW = 8.18 ± 1.35 kg) were assigned to 3 dietary treatments based on BW and gender in a randomized complete block design (5 replicates/treatment and 4 piglets [2 barrows and 2 gilts]/replicate): (1) an antibiotic-free diet (control, CON); (2) CON + 6% wheat bran (WB); (3) CON + 4% sugar beet pulp (SBP). Dietary WB supplementation tended to increase ADG compared with CON from d 1 to 14 (P = 0.051) and from d 1 to 28 (P = 0.099). Supplementation of WB increased (P < 0.05) G:F compared with CON and SBP from d 1 to 14 and from d 1 to 28. Compared with CON, the addition of WB reduced (P < 0.05) diarrhea rate from d 1 to 14 and tended (P = 0.054) to reduce diarrhea rate from d 1 to 28. The addition of WB decreased (P < 0.05) serum diamine oxidase activity on d 14, and up-regulated (P < 0.05) ileal mRNA levels of occludin on d 28 when compared with CON. Piglets fed WB showed decreased (P < 0.05) serum interleukin-6 levels compared to those fed SBP and decreased (P < 0.05) ileal interleukin-8 levels compared to those fed CON and SBP on d 28. Supplementation of WB increased (P < 0.05) serum levels of immunoglobulin A (IgA), IgG and IgM compared with SBP on d 14, and increased (P < 0.05) the levels of serum IgA and ileal sIgA compared with CON and SBP on d 28. Piglets fed WB showed an enhanced (P < 0.05) α-diversity of cecal microbiota than those fed SBP, while piglets fed SBP showed reduced (P < 0.05) α-diversity of cecal microbiota than those fed CON. Compared with CON, the addition of WB elevated (P < 0.05) the abundance of Lachnospira and cecal butyric acid level. Piglets fed WB also showed increased (P < 0.05) abundances of Lachnospira and unclassified_f_Lachnospiraceae compared with those fed SBP. Collectively, the supplementation of WB to antibiotic-free diets improved performance, immune responses, gut barrier function and microbiota compared with the CON and SBP fed piglets. Therefore, supplementing weaned piglets with WB was more effective than SBP.     

植物粉剂对肉鸡生长性能、肠道菌群数量和肌肉脂肪酸的影响

文章旨在评估植物粉剂(大蒜粉和石莲花粉)对1～42?d肉鸡生长性能、肠道菌群和肌肉脂肪酸组成的影响.试验选择平均初始体重为(48.33±0.47)g的1日龄商品肉仔鸡640只,随机分为4组,每组5个重复,每个重复32只.对照组饲喂基础日粮,药物组肉鸡饲喂基础日粮,但通过饮水补充2?mg/L维吉尼亚霉素水溶剂,大蒜粉组肉...     

Dietary inclusion of different multi-strain complex probiotics; effects on performance in broilers

1. This study was designed to evaluate the effects of two different complex probiotic supplementations on the growth performance, meat quality, excreta microflora, nutrient retention, blood metabolic profile and noxious gas emissions in broilers.

2. A total of 612 conventional healthy 1-d-old Ross 308 broilers with body weight of 41 ± 0.3 g were randomly divided into 3 treatments with 12 replicate cages, with 17 broilers in each cage and fed with the following diets: CON-Basal diet, T1-CON + Probiotic A, T2-CON + Probiotic B.

3. Significant results were observed on body weight gain, but not on feed conversation ratio and feed intake, in the whole experimental period. Increased faecal lactobacillus counts were found with probiotics supplementation. However, no significant effects were found for meat quality, nutrient retention, blood metabolic profile or noxious gas emissions.

4. In conclusion, both multi-strain probiotics had beneficial effects on growth performance, drip loss percentage and faecal Lactobacillus counts in broilers.

     

黄芩黄酮对肉仔鸡生长性能和肠道菌群的影响

试验旨在探讨不同添加水平黄芩黄酮对肉仔鸡生长性能和肠道菌群的影响。选择500只1日龄AA肉仔鸡,采用单因子设计随机分为5个处理,每个处理5个重复,每个重复20只鸡,对照组饲喂基础日粮,试验组在基础饲料基础上分别添加5、10、15、20 mg/kg黄芩黄酮,进行为期49 d的饲养试验。分别于第21、35、49天时称重,计算平均体重、日增重、料重比,于实验结束时采集肠道内容物,测定肠道微生物菌群数量。结果表明,各处理组平均体重较空白对照组均有所增加,其中10 mg/kg添加组最高(P>0.05),5 mg/kg添加组显著提高日采食量(P<0.05),对F/G和ADG影响不显著(P>0.05)。49日龄时,各试验组与对照组相比,大肠杆菌和沙门氏菌数量显著降低(P<0.05);乳酸杆菌(需氧)和双歧杆菌数量均高于对照组(P>0.05)。由此可知,日粮中添加适量黄芩黄酮在一定程度上可以促进肉仔鸡生长,改善肠道微生物菌群,其中添加10 mg/kg黄芩黄酮效果较好。     

Effects of a protected inclusion of organic acids and essential oils as antibiotic growth promoter alternative on growth performance,intestinal morphology and gut microflora in broilers

This experiment was conducted to investigate the effects of protected essential oils and organic acids mixture on poultry feeding. A total of 450 1‐day‐old Cobb 500 chicks were randomly allotted into three treatments with six replicates. Birds were offered a basal diet (C), basal diet with 0.15 g/kg enramycin premix (A) and basal diet with 0.30 g/kg protected essential oils and organic acids mixture product (P). The results showed that protected essential oils and organic acids mixture supplementation reduced average daily feed intake and ratio of feed to gain (F/G) at 22–42 days of age, and F/G during 1–42 days of age also declined (P < 0.05). Product supplementation improved spleen index, villus height and crypt depth of the jejunum at 42 days when compared with the control (P < 0.05). In addition, secretory immunoglobulin A level of ileal mucosa and trypsin and chymotrypsin activities of intestinal tract were higher in the P treatment. Bacterial sequence analysis of the intestinal tract revealed that protected essential oils and organic acids mixture supplementation changed gut microflora mainly in Lactobacillus. These data suggested that dietary mixture of organic acids and essential oils addition could be used in the poultry industry as an antibiotic growth promoter alternative.     

Effects of lysolecithin supplementation in low-energy diets on growth performance,nutrient digestibility,viscosity and intestinal morphology of broilers

1. The study aimed to investigate the effect of lysolecithin supplementation in low-energy diets on growth, nutrient digestibility and intestinal mucosa characteristics of broilers.

2. A total of 800 one-d-old Ross 308 broiler chickens were assigned to 4 dietary treatments consisting of 10 replicates of 20 broilers each. Broilers were fed with 4 different diets: (i) HE: positive control group broilers received a diet with unaltered energy; (ii) LE: negative control group broilers received a diet with lower energy of about 0.27 MJ/kg; (iii) LElys500: broilers received a diet similar to LE supplemented with 500 g/tn lysolecithin product (Lysoforte Booster Dry^TM); and (iv) LElys300: broilers received a diet similar to LE supplemented with 300 g/tn lysolecithin product. The experimental period was 42 d.

3. Body weight gain in treatments HE was higher than LE during the overall experimental period, while LElys500 and LElys300 had intermediate values. Feed conversion ratio was lower in HE and LElys500 than LE group, while the LElys300 had intermediate values. Fat digestibility was improved in both LElys 500 and LElys300 compared to the HE group. Apparent metabolisable energy (AMEn) was higher in HE, LElys500 and LElys300 than LE. Ileum viscosity at 42 d was also affected, being higher in LE group compared to HE. At 28 d mucosal thickness was lower both in LElys500 and LElys300 compared to HE and LE, while no difference occurred between treatment proliferation patterns of duodenal epithelial cells.

4. These findings indicated that lysolecithin supplementation at 500 g/tn of feed in low-energy diets maintained broiler performance. Supplementation of reformulated low-energy diets induced an increase in digesta viscosity. Lysolecithin supplementation resulted in variable alterations in the duodenum mucosal morphology.     

不同种类有机酸对肉鸡生长性能、养分利用率和肠道菌群的影响研究

本试验研究不同种类有机酸对肉鸡生长性能、养分利用率和肠道菌群的影响。将240只1日龄艾维茵肉鸡随机分为4个处理(对照组、1.5%柠檬酸组、1.5%延胡索酸组、0.2%复合酸化剂组),每个处理6个重复,每个重复10只鸡。在试验17～20d和38～41d分别进行代谢试验;在试验第21天和第42天进行屠宰试验。结果表明:肉鸡日粮中添加1.5%柠檬酸、1.5%延胡索酸和0.2%复合酸化剂不同程度改善肉鸡生产性能;提高前期阶段饲粮能量和养分的利用率;对42日龄盲肠内容物的pH值有一定影响,同时,柠檬酸和复合酸化剂能显著促进肉鸡42日龄直肠乳酸杆菌的增殖;综合分析所有参数,0.2%复合酸化剂的作用效果最优。     

Effects of essential oil supplementation of a low‐energy diet on performance,intestinal morphology and microflora,immune properties and antioxidant activities in weaned pigs

A total of 144 weaned piglets were used to evaluate the effects of essential oil (EO) supplementation of a low‐energy diet on performance, apparent nutrient digestibility, small intestinal morphology, intestinal microflora, immune properties and antioxidant activities in weaned pigs. Pigs received a low‐energy diet (negative control, NC, digestible energy = 3250 kcal/kg), NC plus 0.025% EO or a positive control diet (PC, digestible energy = 3400 kcal/kg) for 28 days. Growth performance was similar between the EO group and PC group. However, EO supplementation increased (P < 0.05) average daily gain and the apparent digestibility of dry matter, crude protein and energy compared with pigs fed the NC diet. Greater (P < 0.05) villus height and lower (P < 0.05) counts of Escherichia coli and total anaerobes in the rectum in the EO group were observed compared with NC or PC groups. Pigs fed EO diet had higher (P < 0.05) concentrations of albumin, immunoglobulin A (IgA), IgG and total antioxidant capacity and lower fecal score than pigs fed the PC and NC diets. Above all, this study indicates that supplementation of EO to a low‐energy pig diet has beneficial results and obtains similar performance compared with normal energy (PC) diet.     

抗菌肽对断奶仔猪生长性能、养分消化率、肠道微生物含量及绒毛结构的影响

文章旨在研究日粮添加不同水平抗菌肽替代抗生素对断奶仔猪生长性能、养分消化率、肠道微生物含量及绒毛结构的影响。试验选择平均体重为(5.76±0.02)kg的21 d断奶的杜×长×大仔猪672头,根据个体大小随机分为4组,每组4个重复,每个重复42头。试验分为1～14 d和15～28 d两个阶段,对照组饲喂基础日粮+60 mg/kg盐霉素,抗菌肽组饲喂基础日粮+0、50或100 mg/kg抗菌肽。试验进行28 d。对照组较抗菌肽组显著提高了断奶仔猪28 d体重(P <0.05),1～14 d和1～28 d日增重(P <0.05),1～14 d、15～28 d、1～28 d采食量,显著降低了1～28 d料重比(P <0.05)。随着日粮抗菌肽添加水平的升高,28 d体重、1～14 d、15～28 d及1～28 d日增重显著升高(P <0.05)。对照组较抗菌肽组显著提高了断奶仔猪14和28 d干物质、14 d粗蛋白质表观消化系数(P <0.05)。对照组较抗菌肽组显著降低了14和28 d粪中大肠杆菌含量(P <0.05),且总厌氧菌、梭菌和大肠杆菌含量随抗菌肽添加水平的升高而显著降低(P <0.05);与抗菌肽组相比,对照组显著降低了回肠总厌氧菌含量(P <0.05)。饲喂对照组日粮的断奶仔猪较抗菌肽组显著降低了空肠隐窝深度(P <0.05),显著提高了空肠绒毛高度与隐窝深度的比值(P <0.05)。根据试验结果推断,日粮添加抗菌肽可以作为抗生素替代品,具有提高断奶仔猪生长性能、干物质和粗蛋白质的表观消化率、绒毛形态及降低粪中有害菌含量的作用。     

Effects of three major protein sources on performance,gut morphology and fermentation characteristics in broilers

ABSTRACT

1. This study determined the effects of three protein sources (PS), each at two digestibility crude protein (DCP) levels, on performance, gut morphology and fermentation characteristics in the hindgut of broilers.

2. It was hypothesised that broilers fed ingredients high in indigestible CP, i.e. rapeseed meal (RSM) or maize gluten (MG), could potentially cause reduced growth, impaired gut health, and more protein fermentation products in caecal digesta. Increasing the DCP level in each of the indigestible CP diets may compensate for these detrimental effects.

3. In total, 288 one-d-old male Ross 308 broilers were used in a completely randomised 3 × 2 factorial design, with six replicate pens per treatment. Three PS: soybean meal (SBM), rapeseed meal (RSM) or maize gluten (MG), and two DCP levels: 15.8 and 17.2% were used.

4. Broilers fed SBM had increased feed intake and BWG and improved FCR compared with those fed RSM and MG diets. Broilers fed high DCP had better performance compared with those on low DCP. No significant effects of PS or DCP level were found on gastrointestinal tract development, caecal ammonia or volatile fatty acid concentrations.

5. Broilers fed SBM had longer villi, smaller crypts and increased villus height to crypt depth ratio compared with those fed RSM and MG diets. Broilers fed RSM diet had a lower caecal pH, and had 16.5% and 14.9% more branched chain fatty acid contents in caecal digesta compared with those fed SBM and MG diets, respectively, indicating more proteolytic fermentation.

6. Replacing SBM by RSM and MG negatively affected growth performance and gut morphology. Hindgut protein fermentation was substantially increased in RSM fed birds.

7. To a certain extent, retarded growth performance in RSM and MG fed birds could be counterbalanced by increasing the dietary level of digestible CP.     

Evaluating two multistrain probiotics on growth performance,intestinal morphology,lipid oxidation and ileal microflora in chickens

An experiment was conducted to investigate the supplementation of two commercially available multistrain probiotics as an alternative to antibiotics on growth performance, intestinal morphology, lipid oxidation and ileal microflora in broiler chickens. A total of 280‐day‐old ROSS 308 mixed‐sex broiler chickens with an average initial body weight of 42 ± 0.5 g were randomly divided into four treatments with five replicate cages of 14 birds each cage in a completely randomized design and fed with the following diets for 42 day: (a) control (CON) (antibiotic‐free diet), (b) antibiotic (ANT) (CON + Avilamycin 150 g/ton feed), (c) probiotic A (CON + Protexin^® 150 g/ton feed) and (d) probiotic B (CON + Bio‐Poul^® 200 g/ton feed). The results showed the broilers fed the ANT diet had greater average daily gain than broilers fed the CON diet during day 1–14 (p < 0.05). At day 42, two birds were randomly selected per replicate for evaluation intestinal morphology, lipid oxidation and ileal microflora. birds fed diet supplemented with probiotic A and probiotic B increased villus height and goblet cells numbers in the jejunum and villus height to crypt depth ratio and villus height in the ileum as compared to birds fed CON diet (p < 0.05). The malondialdehyde value was reduced (p < 0.05) in the ANT, probiotic B and probiotic A groups compared with the CON group. The Lactobacillus population was increased and Clostridium spp. population decreased in the ileum of broilers fed diets containing the probiotic B and probiotic A compared with those fed CON diet (p < 0.05). The results from this study indicate that the probiotic A (Protexin^®) and probiotic B (Bio‐Poul^®) used in this trial may serve as alternatives to ANT.     

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.