Impact of salinomycin on the intestinal microflora of broiler chickens

Background  

The ionophoric coccidiostat salinomycin is widely used in chicken feed. In the near future the use of ionophore coccidiostats may be banned as has been the case for other antimicrobial growth promoters. This study was conducted to examine the effect of salinomycin on Campylobacter jejuni infection and on the composition of the caecal microflora in broiler chickens.     

Effects of dietary antibiotics on intestinal microflora in broiler chickens

Changes were examined in the intestinal microflora in broiler chickens fed a diet containing antibiotics to obtain fundamental information on the mechanisms of beneficial effect of the antibiotics upon livestock production. Three antibiotics (colistin, bacitracin, and enramycin) were employed as feed additives. Experiments were conducted with broiler chickens in two ways. In one way dietary antibiotics were fed continually at levels approved for use as feed additives for a long term. In the other they were fed the same antibiotics for a short term. Significant changes in microflora were observed mainly in such bacterial groups as aerobic bacteria and Lactobacillus. In the long term administration, three possible modes of variance in the bacterial flora were postulated: Changes directly related to the antibacterial spectrum of antibiotics. Antagonistic changes related to an ecological balance in the bacterial flora. Changes in quantitative balance of bacteria constituting each bacterial group. The change in the intestinal microflora during administration of the antibiotic diet was expressed as a complex form of these transition modes. In the short term administration, it was demonstrated that the effect of the antibiotic diet lingered even 7 days after administration. This suggests that antibiotics used as feed additives may possibly affect the stability of the intestinal microflora.     

The effect of microbial challenge on the intestinal proteome of broiler chickens

Background

In poultry production intestinal health and function is paramount to achieving efficient feed utilisation and growth. Uncovering the localised molecular mechanisms that occur during the early and important periods of growth that allow birds to grow optimally is important for this species. The exposure of young chicks to used litter from older flocks, containing mixed microbial populations, is a widely utilised model in poultry research. It rarely causes mortality but effects an immunogenic stimulation sufficient enough to cause reduced and uneven growth that is reflective of a challenging growing environment.

Methods

A mixed microbial challenge was delivered as used litter containing Campylobacter jejuni and coccidial oocysts to 120 male Ross 308 broiler chicks, randomly divided into two groups: control and challenged. On day 12, 15, 18 and 22 (pre- and 3, 6 and 10 days post-addition of the used litter) the proximal jejunum was recovered from 6 replicates per group and differentially abundant proteins identified between groups and over time using 2D DiGE.

Results

The abundance of cytoskeletal proteins of the chicken small intestinal proteome, particularly actin and actin associated proteins, increased over time in both challenged and control birds. Villin-1, an actin associated anti-apoptotic protein, was reduced in abundance in the challenged birds indicating that many of the changes in cytoskeletal protein abundance in the challenged birds were as a result of an increased rate of apoptosis. A number of heat shock proteins decreased in abundance over time in the intestine and this was more pronounced in the challenged birds.

Conclusions

The small intestinal proteome sampled from 12 to 22 days of age showed considerable developmental change, comparable to other species indicating that many of the changes in protein abundance in the small intestine are conserved among vertebrates. Identifying and distinguishing the changes in proteins abundance and molecular pathways that occur as a result of normal growth from those that occur as a result of a challenging microbial environment is important in this major food producing animal.

     

Composition of the enterococcal intestinal flora of chickens in a tropical area

Enterococcus faecalis was the most frequently occurring enterococcal species in caeca and cloacal swabs of chickens in Assam, India. In chickens less than 8 weeks of age Ent. faecium, Ent. durans and Ent. avium were also found, but infrequently. Enterococcus hirae , which is potentially pathogenic in chickens of less than 1 week of age, was found only in chickens of more than 8 weeks. Except for a higher frequency of Ent. faecalis , the composition of this flora was essentially the same as that in European temperate climates.     

Indigestible carbohydrates alter the intestinal microbiota but do not influence the performance of broiler chickens

Aims:  Prebiotics are a potential alternative to in-feed antimicrobials to improve performance of chickens. We investigated the effects of mannanoligosaccharide (MOS) and fructooligosaccharide (FOS) on growth, performance and the intestinal microbiota.
Methods and Results:  Cobb 500 birds were fed either: Control, starter diet without antimicrobials; ZnB, Control + 50 ppm zinc bacitracin; MOS, Control + 5 g kg⁻¹ MOS; or FOS, Control + 5 g kg⁻¹ FOS. An energy metabolism study was conducted and intestinal microbial communities assessed by T-RFLP and Lac PCR-DGGE. Diet did not influence performance. Ileal microbial communities were significantly different in ZnB-fed birds compared to all diets, and FOS-fed chickens compared to Control. MOS-fed chickens had a different caecal profile to ZnB and FOS-fed birds. Consensus Lac PCR-DGGE profiles indicated Lactobacillus communities clustered according to diet with Lactobacillus johnsonii characteristic of ZnB diet. Control and MOS-fed chickens displayed significantly different jejunal Lactobacillus profiles to each other whilst ileal profiles were different between MOS and FOS-fed birds.
Conclusion:  Prebiotics influenced the intestinal microbiota, but did not affect performance.
Significance and Impact of the Study:  In light of pressure for in-feed antimicrobial withdrawal, the impact of alternative compounds on the intestinal microbiota and bird performance is critical to the poultry industry.     

Spatial and temporal variation of the intestinal bacterial community in commercially raised broiler chickens during growth

The objective of this study was to determine whether host, compartment, or environmental specific factors play an important role in the establishment of the intestinal microflora in broiler chickens during growth. This objective was addressed using a 16S rDNA approach. PCR-amplicons from the V6 to V8 regions of the 16S rDNA of intestinal samples were separated by denaturing gradient gel electrophoresis (DGGE). The number of bands in all intestinal compartments increased when broilers grew older, indicating that the dominant bacterial community becomes more complex when chickens age. Each chicken had a unique banding pattern for all locations in the intestinal tract, irrespective of the age of chickens. This suggests that host-related factors affect the establishment of the dominant bacterial community. Banding patterns of intestinal compartments within one chicken were different from each other for broilers older than 4 days, except for both ceca which were highly similar. In 4-day-old broilers, banding patterns from crop, duodenum, and ileum were very similar. We conclude that (unknown) host specific factors play an important role in the development of the intestinal bacterial community in each broiler chicken. Furthermore, compartment-specific factors play an important role in the bacterial development of each intestinal compartment within one chicken.     

Minimum inhibitory concentrations of intestinal Escherichia coli from broiler chickens after oral administration of apramycin

This study describes the influence of apramycin on minimum inhibitory concentrations (MIC) of intestinal Escherichia coli in young broiler chickens, after oral administration of the antibiotic at a dosage equivalent to a prophylactic course of treatment for 10 d. The bacteria were isolated from cloacal swabs and caecal contents. MICs were determined by agar dilution procedures. MIC of apramycin for the investigated strains ranged from 1 μg ml^-1 to 16 μg ml^-1. Strains obtained from undosed birds mainly had MIC values of 1 μg ml^-1. MIC values of 8 μg ml^-1 or more were recorded only among isolates obtained from chickens which had received apramycin. Administration of apramycin resulted in a slight but statistically significant increase in the average MIC. Statistically higher average MICs were recorded among isolates from cloacal swabs 10 d after withdrawal until the end of the experiment. For strains from caecal contents, this was demonstrated only on one sampling occasion, 15 d after withdrawal.     

Inheritance of fertility in broiler chickens

Background

The fertility of a chicken''s egg is a trait which depends on both the hen that lays the egg and on her mate. It is also known that fertility of an individual changes over the laying period.

Methods

Longitudinal models including both random genetic and permanent environmental effects of both the female and her male mate were used to model the proportion of fertile eggs in a pedigree broiler population over the ages 29-54 weeks.

Results

Both the male and the female contribute to variation in fertility. Estimates of heritability of weekly records were typically 7% for female and 10% for male contributions to fertility. Repeatability estimates ranged from 24 to 33%, respectively. The estimated genetic variance remained almost constant for both sexes over the laying period and the genetic correlations between different ages were close to 1.0. The permanent environment components increased substantially towards the end of the analyzed period, and correlations between permanent environment effects at different ages declined with increasing age difference The heritability of mean fertility over the whole laying period was estimated at 13% for females and 17% for males. A small positive correlation between genetic effects for male and female fertility was found.

Conclusion

Opportunities to improve fertility in broiler stocks by selection on both sexes exist and should have an impact throughout the laying period.     

Characterization of antibiotic-resistant and potentially pathogenic Escherichia coli from soil fertilized with litter of broiler chickens fed antimicrobial-supplemented diets

The objective of this study was to characterize antimicrobial resistance and virulence determinants of Escherichia coli from soil amended with litter from 36-day-old broiler chickens ( Gallus gallus domesticus ) fed with diets supplemented with a variety of antimicrobial agents. Soil samples were collected from plots before and periodically after litter application in August to measure E. coli numbers. A total of 295 E.?coli were isolated from fertilized soil samples between August and March. Antibiotic susceptibility was determined by Sensititre, and polymerase chain reaction was performed to detect the presence of resistance and virulence genes. The results confirmed that E.?coli survived and could be quantified by direct plate count for at least 7 months in soil following litter application in August. The effects of feed supplementation were observed on E.?coli numbers in November and January. Among the 295 E.?coli, the highest antibiotic resistance level was observed against tetracycline and β-lactams associated mainly with the resistance genes tetB and bla(CMY-2), respectively. Significant treatment effects were observed for phylogenetic groups, antibiotic resistance profiles, and virulence gene frequencies. Serotyping, phylogenetic grouping, and pulsed-field gel electrophoresis confirmed that multiple-antibiotic-resistant and potentially pathogenic E.?coli can survive in soil fertilized with litter for several months regardless of antimicrobials used in the feed.     

Effects of inulin and di-d-fructose dianhydride-enriched caramels on intestinal microbiota composition and performance of broiler chickens

In vitro and in vivo experiments were designed to evaluate the effectiveness of laboratory-made di-d-fructose dianhydride (DFA)-enriched caramels. The DFA-enriched caramels were obtained from d-fructose (FC), d-fructose and sucrose (FSC), or d-fructose and β-cyclodextrin (FCDC). In the in vitro experiment, raftilose and all caramels increased (P<0.05) l-lactate concentration and decreased (P<0.05) pH. Total short-chain fatty acid concentration was higher (P<0.05) than controls in tubes containing raftilose, FSC, FCDC and commercial sucrose caramel (CSC). Raftilose, and all caramels tested except FSC and FC (1%), increased (P<0.01) lactobacilli log₁₀ number of copies compared with the non-additive control. FSC, FCDC and CSC increased (P<0.01) the bifidobacteria number of copies as compared with controls. All additives, except FCDC, decreased (P<0.01) Clostridium coccoides/Eubacterium rectale log number of copies. Compared with controls, raftilose, FC and CSC led to lower (P<0.01) Escherichia–Shigella and enterobacteria. For the in vivo experiment, a total of 144 male 1-day-old broiler chickens of the Cobb strain were randomly assigned to one of the three dietary treatments for 21 days. Dietary treatments were control (commercial diet with no additive), inulin (20 g inulin/kg diet) and FC (20 g FC/kg diet). Final BW of birds fed FC diet was higher (P<0.01) than controls or inulin-fed birds, although feed: gain values were not different. Feed intake of chickens fed FC was higher (P<0.01) than that of inulin-fed birds but not statistically different from controls. Crop pH values were lower (P<0.01) in birds fed FC diet as compared with control diet, with inulin-fed chickens showing values not different from control- or FC-fed birds. Lower (P<0.05) lactobacilli number of copies was determined in the crop, ileum and caeca of birds fed the inulin diet compared with the control diet. Inulin supplementation also resulted in lower (P<0.05) C. coccoides/E. rectale, bacteroides and total bacteria in caecal contents. Addition of FC to broiler diets gave place to lower (P<0.05) enterobacteria and Escherichia–Shigella in crop and caecal contents compared with controls. The bacteroides number of copies increased (P<0.05) as compared with controls in the ileum, but decreased (P<0.05) in the caeca of chickens fed the FC diet. Energy, ADF, NDF and non-starch polysaccharides faecal digestibilities were greater (P<0.05) than controls in chickens fed diets containing inulin or FC. Fat digestibility was higher (P<0.05) in FC-fed birds compared with controls or inulin-fed chickens. In conclusion, DFA-enriched caramels tested here, particularly FC, may represent a type of new additives useful in poultry production.     

Nutritive value of ensiled broiler litter for cattle

Broiler litter, consisting of bedding material (chopped wheat straw or rice hulls), excreta, wasted feed and feathers was ensiled at 40 or 50% moisture for 42 days. Cheddar cheese whey was added to adjust the moisture level in some of the silage. The dry matter digestibility in vitro (IVDMD), after 21 days of ensiling was greater for silage containing the wheat straw base than for that with the rice hull base. Whey improved the IVDMD of the wheat straw base silage but not that of the rice hull base silage. Moisture levels did not influence the IVDMD. In a second trial, broiler litter consisting of chopped wheat straw bedding, excreta, wasted feed and feathers was ensiled for 28 days at approximately 45% dry matter. The litter was ensiled as: (1) litter alone; (2) litter plus Irish potato cannery waste (IPW); (3) litter plus ground maize, and (4) litter plus ground grain sorghum. The materials added supplied 33% of the dry matter of the silages. The pH of the silages 1 and 4 weeks after ensiling was (1) 6.00, 5.83; (2) 5.00, 4.56; (3) 4.96, 4.80; and (4) 4.92, 4.78. Total faecal and urine collection trials were conducted using 12 Holstein steers having an average body weight of 200 kg. Dry matter digestibility was greater (P < 0.01) for silages 2, 3 and 4. Digestible energy and protein were 61.2, 70.6; 65.3, 74.6; 65.2, 71.2; and 68.2, 76.4% for silages 1 through 4.     

Effects of sodium butyrate and salinomycin upon intestinal microbiota, mucosal morphology and performance of broiler chickens

The effect of dietary sodium butyrate (SB) or salinomycin (SAL) or both additives on performance, small intestinal morphology and microbial ecology of broiler chickens was studied. A growth trial was conducted with 96 Ross 308 female broilers from 1 to 30 days of age. Four treatment groups were fed with a non-supplemented control diet or three experimental diets supplemented with i) 300 mg SB (Adimix 30 coated) per kg, ii) 60 mg SAL (Sacox) per kg or iii) both additives in combination. Feed intake and body-weight gain decreased and gain-to-feed ratio increased due to SAL supplementation, while addition of SB did not affect performance in comparison with the control diet but positively affected feed intake and body-weight gain in comparison with birds fed the SAL-supplemented diet. Villus height in jejunum decreased, while crypt depth increased due to SAL supplementation. Addition of SB increased crypt depth in jejunum. No significant effect of either additive was observed in ileum morphology. Total short-chain organic acids concentration in ileal digesta decreased with SAL supplementation, mainly due to lower lactic acid concentration, but no effects were observed in the caeca. The SAL supplementation was accompanied by a pH increase in ileum and a pH decrease in caecum. No significant effect of SB addition was observed for these parameters. Total bacterial numbers and Lactobacillus [lactic acid bacteria (LAB)] counts in ileal and caecal contents were lower in birds fed with SAL-supplemented diet in comparison with birds fed with control or SB diet. DNA fingerprints revealed SAL supplementation to affect the microbial population by suppressing dominating LAB, potentially L. aviarius. The presented results show that dietary SAL, supplemented alone or in combination with SB, suppressed the microbial activity and altered the microbial community structure mainly in ileum. SAL alone negatively affected feed intake and body-weight gain; however, the effect was ameliorated by SB supplementation.     

Effects of sodium butyrate and salinomycin upon intestinal microbiota,mucosal morphology and performance of broiler chickens

The effect of dietary sodium butyrate (SB) or salinomycin (SAL) or both additives on performance, small intestinal morphology and microbial ecology of broiler chickens was studied. A growth trial was conducted with 96 Ross 308 female broilers from 1 to 30 days of age. Four treatment groups were fed with a non-supplemented control diet or three experimental diets supplemented with i) 300 mg SB (Adimix 30 coated) per kg, ii) 60 mg SAL (Sacox) per kg or iii) both additives in combination. Feed intake and body-weight gain decreased and gain-to-feed ratio increased due to SAL supplementation, while addition of SB did not affect performance in comparison with the control diet but positively affected feed intake and body-weight gain in comparison with birds fed the SAL-supplemented diet. Villus height in jejunum decreased, while crypt depth increased due to SAL supplementation. Addition of SB increased crypt depth in jejunum. No significant effect of either additive was observed in ileum morphology. Total short-chain organic acids concentration in ileal digesta decreased with SAL supplementation, mainly due to lower lactic acid concentration, but no effects were observed in the caeca. The SAL supplementation was accompanied by a pH increase in ileum and a pH decrease in caecum. No significant effect of SB addition was observed for these parameters. Total bacterial numbers and Lactobacillus [lactic acid bacteria (LAB)] counts in ileal and caecal contents were lower in birds fed with SAL-supplemented diet in comparison with birds fed with control or SB diet. DNA fingerprints revealed SAL supplementation to affect the microbial population by suppressing dominating LAB, potentially L. aviarius. The presented results show that dietary SAL, supplemented alone or in combination with SB, suppressed the microbial activity and altered the microbial community structure mainly in ileum. SAL alone negatively affected feed intake and body-weight gain; however, the effect was ameliorated by SB supplementation.     

Effects of dietary sodium butyrate supplementation on the intestinal morphological structure,absorptive function and gut flora in chickens

A study was carried out to investigate the effects of dietary sodium butyrate (SB) on the intestine and growth performance in chickens. Three hundred and thirty six day-old AA broiler chicks were allocated at random into four groups with six replicates each. Four groups were fed with basal diet (control) or diets supplemented with SB at the level of 500, 1000, 2000 mg/kg. Body weight gain increased linearly during the period from 0 to 21 days as the dietary supplementation of SB increased (P<0.05). Dietary supplementation of SB influenced feed conversion ratio (FCR) in a positive quadratic fashion during the period from 0 to 42 days (P<0.05). Dietary SB did not influence the absorptive function of jejunum (P>0.05). The concentrations of DNA, RNA, and protein in duodenal mucosa showed negative quadratic responses to the increase of dietary SB supplementation level (P<0.05). The ratio of villus height to crypt depth increased linearly with the increase of dietary SB supplementation (P<0.01). The Lactobacillus count decreased linearly with the increase of dietary SB supplementation (P<0.01).     

Necrotic enteritis challenge models with broiler chickens raised on litter: evaluation of preconditions, Clostridium perfringens strains and outcome variables

The effect of Clostridium perfringens challenge, number of challenge days, and pre-challenge antibiotic treatment on the induction of necrotic enteritis in broiler chickens raised on litter was studied, and the relationship between bacterial counts and frequency of gut lesions was evaluated. Specific intestinal lesions in randomly selected birds were present despite a lack of disease-specific mortality. Challenge, number of challenge days and frequency of lesions were associated with median counts of C. perfringens. The effect of pre-challenge C. perfringens counts and antibiotics cannot be evaluated unless procedures for the control of pre-challenge infection and methods for the differentiation between wild-type and challenge strains are established.     

Genetic heterogeneity of residual variance in broiler chickens

Aims were to estimate the extent of genetic heterogeneity in environmental variance. Data comprised 99 535 records of 35-day body weights from broiler chickens reared in a controlled environment. Residual variance within dam families was estimated using ASREML, after fitting fixed effects such as genetic groups and hatches, for each of 377 genetically contemporary sires with a large number of progeny (> 100 males or females each). Residual variance was computed separately for male and female offspring, and after correction for sampling, strong evidence for heterogeneity was found, the standard deviation between sires in within variance amounting to 15–18% of its mean. Reanalysis using log-transformed data gave similar results, and elimination of 2–3% of outlier data reduced the heterogeneity but it was still over 10%. The correlation between estimates for males and females was low, however. The correlation between sire effects on progeny mean and residual variance for body weight was small and negative (-0.1). Using a data set bigger than any yet presented and on a trait measurable in both sexes, this study has shown evidence for heterogeneity in the residual variance, which could not be explained by segregation of major genes unless very few determined the trait.     

冠心病患者糖脂代谢与肠道菌群平衡的关系

研究冠心病(CHD)患者糖脂代谢与肠道菌群平衡的关系, 为该类患者的治疗提供参考。

选择2020年4月至2021年4月我院收治的79例CHD患者(CHD组)和82例健康体检者(对照组)为研究对象进行横断面研究。详细采集两组对象一般资料, 同时完成体格检查和生命体征检测并计算体质量指数(BMI)。采集两组对象入组第1天时空腹外周静脉血, 检测空腹血糖(FPG)和空腹胰岛素(FINS)水平并计算稳态模型胰岛素抵抗指数(HOMA-IR), 检测血清总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)等脂质代谢指标水平。收集两组研究对象新鲜晨便并采用荧光定量PCR法检测肠道双歧杆菌、乳杆菌、拟杆菌、梭菌和白假丝酵母数量。比较两组对象基本资料、糖脂代谢指标和肠道菌群分布, 分析CHD患者肠道菌群与糖脂代谢指标相关性。

CHD组患者HOMA-IR(t=2.729, P=0.007)和血清TC(t=2.915, P=0.030)、TG(t=2.567, P=0.011)水平显著高于对照组, 血清LDL-C(t=2.129, P=0.035)水平显著低于对照组。CHD组患者肠道双歧杆菌数量(t=2.247, P=0.026)和拟杆菌/梭菌比值(t=2.111, P=0.036)低于对照组。CHD患者肠道双歧杆菌数量和拟杆菌/梭菌比值与HOMA-IR(r=-0.384、-0.354, P < 0.001、=0.012)以及血清TC(r=-0.361、-0.329, P=0.005、0.027)、TG(r=-0.358、-0.341, P=0.009、0.020)和LDL-C(r=-0.326、-0.317, P=0.031、0.038)水平均呈显著负相关。

CHD患者糖脂代谢和肠道菌群分布均存在显著异常, 且HOMA-IR、血清TC、TG和LDL-C水平均与肠道双歧杆菌数量和拟杆菌/梭菌比值呈负相关, 因此对肠道菌群进行检测和合理干预有利于调节糖脂代谢。