Healthy Broiler Chickens Research Articles

The effects of in ovo pollen extract injection on growth parameters, ileal histomorphology and caecal microflora in fasted broiler chicks

This study was carried out to determine the effects of in ovo pollen extract injection on growth parameters, ileal histomorphology, and caecal microflora of fasted broiler chicks. In this experiment, 2×2 factorial experimental design was used. One d old, 120 healthy broiler chicks were allocated to 4 treatment groups and 6 replicates (5 mixed sex chicks allocated each replicates). Treatment groups were: A) Pollen extract injection and 24 h fasting (P24); B) Pollen extract injection and 48 h fasting (P48), C) Control, no injection 24 h fasting (C24) and D) Control, no injection 48 h fasting (C48). The experiment lasted 21 days. Live weight, feed consumption, feed conversion ratio were recorded weekly. Ileal histomorphology, caecal microbiota, organ weight were recorded at 21th days of experiment. In ovo pollen extract injection did not affect hatchability rate. At the end of 21 days, in ovo pollen extract injection did not affect feed intake, live weight gain, feed conversion ratio, inner organ development and ileal villi width irrespective to fasting 24 h and 48 h. In ovo pollen extract injection increased ileal villi length, caecal lactic acid bacteria and Saccharomyces Cerevisiae count, decreased caecal Enterobactericaea count. In conclusion, in ovo pollen extract injection can be applied for broiler eggs to improve weight gain, better digestion and gut health.

Detection of a Newly Described Bacteriocin, Perfrin, Among Clostridium perfringens Isolates from Healthy and Diseased Ostriches and Broiler Chickens in Iran.

Necrotic enteritis due to Clostridium perfringens strains harboring the netB gene is a well-known disorder in poultry. The aim of this study was to investigate the association of a novel bacteriocin, perfrin, with netB among isolates from healthy and diseased ostriches and broiler chickens. Forty-six C. perfringens isolates from broiler chickens and ostriches collected from 2010 to 2014 were included in this study and subjected to PCR to detect netB and perfrin genes. Six (60%) and 9 (25%) isolates were positive for both netB and perfrin genes in broilers and ostriches, respectively. Statistical analysis found a significant difference between healthy and diseased flocks for perfrin both in broilers and ostriches. For netB, the significant difference was only found between healthy and diseased ostrich flocks. This is the first report of the presence of perfrin in netB-positive C. perfringens strains in ostriches.

Characterization of Clostridium perfringens Strains Isolated from Healthy and Necrotic Enteritis-Afflicted Broiler Chickens.

Necrotic enteritis (NE) is an important enteric disease in poultry, and Clostridium perfringens (CP) type A strains are the primary etiology. NE is responsible for annual losses of US $6 billion to the poultry industry in the United States. An increase in the incidence of NE has been also associated with withdrawal of antibiotic growth promoters from poultry feed. In this study, CP strains isolated from healthy and NE-afflicted birds were characterized microbiologically and molecularly, and their virulence was experimentally tested in chickens. All strains were hemolytic, lecithinase positive, and identified as CP by biochemical tests. Three distinct colony morphologies were seen in brain-heart infusion media with 0.3% agarose, FeSO4, and ZnCl2. The CP strains responded differently to iron chelation with 2,2'-bidypinol. PCR toxinotyping showed that all tested strains were alpha toxin-positive, seven (N11, N10, CP1, CP5, CP13, JGS, and Del1) were beta2-toxin-positive, and only one (Del1) was necrotic enteritis toxin B-like-positive. In vivo studies indicated that most isolates, including strain N11 isolated from the normal chicken gut, were sufficiently virulent to produce NE disease in the Eimeria/CP dual infection model. The Del1 and N11 strains merit further investigation to identify their virulence factors and immune-protective antigens.

Oral Bioavailability and Plasma Disposition of Pefloxacin in Healthy Broiler Chickens.

The pharmacokinetics of pefloxacin after single 10 mg/kg BW intravenous (IV) and oral doses were studied in healthy broiler chickens. For 24 h, serial blood samples were obtained after IV and oral administration. Concentrations of pefloxacin and its major metabolite N-demethyl pefloxacin (norfloxacin) were measured by use of high-performance liquid chromatography. The plasma concentrations–time data were found to fit a two-compartment open model. For pefloxacin, the elimination half-life (t½β) was 8.44 ± 0.48 and 13.18 ± 0.82 h after IV and oral administration, respectively. After single oral dose, pefloxacin was rapidly absorbed with an absorption half-life (t½a) and TMAX of 0.87 ± 0.07 and 2.01 ± 0.12 h, respectively. Maximum plasma concentration (CMAX) was 4.02 ± 0.31 µg/mL. Oral bioavailability of pefloxacin was found to be 70 ± 2%. Pefloxacin was converted to N-demethyl pefloxacin (norfloxacin). This metabolite represented 5% of the parent drug plasma concentrations. The maximal plasma concentration (CMAX) of N-demethyl pefloxacin (norfloxacin) was calculated as 0.19 ± 0.01 mg/mL. The t½β of N-demethyl pefloxacin after oral pefloxacin administration was 10.93 ± 0.80 h. The results indicate that an oral dose of 10 mg pefloxacin/kg BW, every 24 h, should be effective in treatment of the most systemic infections in poultry.

Diversity of plasmids harboring blaCMY-2 in multidrug-resistant Escherichia coli isolated from poultry in Brazil

Multidrug-resistance (MDR) has been increasingly reported in Gram-negative bacteria from the intestinal microbiota, environment and food-producing animals. Resistance plasmids able to harbor different transposable elements are capable to mobilize antimicrobial resistance genes and transfer to other bacterial hosts. Plasmids carrying blaCMY are frequently associated with MDR. The present study assessed the presence of plasmid-encoded ampC genes (blacmy, blamox, blafox, blalat, blaact, blamir, bladha, blamor) in commensal E. coli isolated from apparently healthy broiler chickens. Furthermore, we characterized the plasmids and identified those harboring the resistance genes. We isolated 144/200 (72%) of E. coli isolates with resistance to cefotaxime and the resistance gene identified was blaCMY-2. The pulsed-field gel electrophoresis (PFGE) analysis showed high diversity of the genetic profiles. The phylogenetic groups A, B1, B2, and D were identified among E. coli isolates and group D was the most prevalent. The PCR-based replicon typing (PBRT) analysis identified four distinct plasmid incompatibility groups (Inc) in MDR isolates. Moreover, plasmids harboring blaCMY-2, ranged in size from 50kb to 150kb and 51/144 (35%) belonged to IncK, 21/144 (14.5%) to IncB/O, 8/144 (5.5%) to IncA/C, 1/144 (0.5%) to IncI, while 63/144 (44.5%) were not typeable by PBRT. Overall, a high prevalence of blaCMY-2 genes was found in a diverse population of commensal MDR E. coli from poultry in Brazil, harbored into different plasmids.

Bioequivalence study of two oral amoxicillin formulations (Biocillin® and Atcomox 87%®) in broiler chickens

Background: The present study was designed to assess the comparative bioequivalence of Biocillin® and Atcomox87%® in healthy broiler chickens after oral administration of both products in a dose of 20 mg amoxicillin base/kg.b.wt.Methods: Twenty-four broiler chickens were divided into two groups. The first group was designed to study the pharmacokinetics of Biocillin®, while the 2nd group was designed to study the pharmacokinetics of Atcomox87%®. Each broiler chicken in both groups was injected intravenously with 20 mg amoxicillin pure standard/kg.b.wt. After 15 days both groups taken orally Biocillin® and Atcomox87%®, respectively. Blood samples were obtained from the wing vein and collected immediately before and at 0.08, 0.16, 0.25, 0.5, 1, 2, 4, 8, 12 and 24 hours after a single intravenous or oral administration.Results: Amoxicillin in both products obeyed a two compartments open model following I.V. injection. The disposition kinetics of Biocillin® and Atcomox87%® following oral administration of 20 mg amoxicillin base/kg.b.wt. revealed that the maximum blood concentration [Cmax] were 10.79 and 10.30 μg/ml and attained at [tmax] of 0.90 and 0.86 hours, respectively. The mean systemic bioavailability of amoxicillin in Biocillin® and Atcomox 87%® after oral administration in healthy chickens was 64.15 and 65.54%, respectively.Conclusions: Atcomox 87%® is bioequivalent to Biocillin® since the ratios of Cmax, AUC0-24 and AUC0-∞ (T/R) were 0.95, 0.91 and 0.90 respectively. These are within the bioequivalence acceptance range. Biocillin® and Atcomox87%® are therefore bioequivalent and interchangeable.

Bioavailability, pharmacokinetics and tissue residues of cephradine (Atocef Forte®) in healthy and colisepticemic broiler chickens

The pharmacokinetics (after single intravenous and oral dose) and tissue residues (orally and daily for five days) of cephradine (20 mg/kg b.wt.) were investigated in healthy and experimentally E.coli infected broiler chickens. Following single intravenous injection to healthy chickens, cephradine obeyed a two compartments open model and the elimination half-life (t1/2β), volume of distribution (Vdss) and total body clearance (CLtot) of cephradine were 2.93 h, 321.5 ml/kg and 0.08 L/h/kg, respectively. Following single oral administration of cephradine to healthy chickens, the peak serum concentration (Cmax) of it was 26.7 µg/mL and achieved (Tmax) at 2.41 h. The oral bioavailability of cephradine was 87.7%. Cephradine was assayed in kidney, liver, heart, gizzard, spleen, breast muscle, thigh muscle and skin after 24, 48, 72, 96 and 120 h after last dose. On conclusion, cephradine is a good choice for treatment of colisepticemia in chickens due to its higher oral bioavailability and distribution.

Comparative analysis of the susceptibility to biocides and heavy metals of extended-spectrum β-lactamase-producing Escherichia coli isolates of human and avian origin, Germany

A total of 174 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates collected from humans (n=140) and healthy broiler chickens (n = 34) was included in the study. The MIC values of alkyl diaminoethyl glycin hydrochloride, benzethonium chloride, benzalkonium chloride, chlorhexidine, acriflavine, copper sulfate, silver nitrate and zinc chloride were determined by the broth microdilution method. Significant differences in MIC distributions were found between human and avian isolates and between CTX-M-, SHV- and TEM-type ESBL E. coli for chlorhexidine, silver nitrate, zinc chloride and copper sulfate by statistical analysis. Isolates with reduced susceptibility were investigated for the presence and localization of tolerance-mediating genes by PCR analysis and Southern blotting. The genes emrE, mdfA, sugE(c), cueO, copA, zntA and zitB were commonly present in isolates with elevated MICs, while the genes qacE∆1, qacF, qacH, sugE(p), cusC and pcoA, were less prevalent. In several isolates, a plasmid localization of the genes qacE∆1, qacF, qacH and sugE(p) on large plasmids >20 kb was detected.

Genome Sequences of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Infantis Strains from Broiler Chicks in Hungary.

Three strains of Salmonella enterica serovar Infantis isolated from healthy broiler chickens from 2012 to 2013 have been sequenced. Comparison of these and previously published S. Infantis genome sequences of broiler origin in 1996 and 2004 will provide new insight into the genome evolution and recent spread of S. Infantis in poultry.

English

One hundred and two Escherichia coli strains isolated from healthy broiler chickens collected from April 2012 to November 2014 in seven geographic areas of western Algeria were studied. Susceptibility pattern to 11 antimicrobial agents was determined by disk diffusion method as recommended by the Clinical Laboratory Standard Institute (CLSI). Antibiograms revealed high levels of resistance to quinolones and fluoroquinolones including nalidixic acid (100%), flumequin (86, 27%) and enrofloxacin (84, 31%), and to other antibiotics, notably: tetracycline (92, 15%), trimethoprim-sulfamethoxazol (80, 39%) and amoxicillin (68, 62%). However, a moderate percentage of strains were resistant to neomycin (31, 37%), chloramphenicol (27, 45%) and nitrofurantoin (21, 56%). Only 7, 84% of the isolates were resistant to gentamicin and all the isolates were susceptible to colistin. All isolated E. coli were resistant to at least three antibiotics. 96, 08% and 91, 12% of the isolates were resistant to at least four and five antimicrobials, respectively. Twenty eight antibiotic resistance patterns of E. coli strains were detected, of which 11 were present significantly. The results of this survey indicate very high levels of resistance to quinolones and to other antibiotics in E. coli from healthy broiler chickens in Algeria, and suggested that this reservoir of resistance may affect the therapeutic potential of fluoroquinolones in human and veterinary medicine. Key words: Escherichia coli, antibiotic resistance, poultry, Algeria.

PREVALENCE AND CHARACTERIZATION OF SHIGATOXIGENIC ESCHERICHIA COLI IN BROILER BIRDS IN MYMENSINGH

Shigatoxigenic Escherichia coli (STEC) are major food-borne pathogens. They transmit to human through contaminated meat and meat products of animals and poultry, and frequently associated with various types of human illness including haemolytic uremic syndrome. This preliminary study showed the prevalence of STEC in 60 cloacal swab samples of live healthy broiler chickens collected randomly when sold at a wholesale market in Mymensingh district of Bangladesh. Isolation and identification of E. coli was carried out using Eosin Methylene Blue (EMB) agar media and 16S rRNA gene specific polymerase chain reaction (PCR). Among the 60 samples, 49 (81.67%) were found positive to E. coli. These E. coli isolates were screened for the detection of STEC by PCR using stx1 and stx2 gene specific primers. Among the 49 positive samples, 5 (10.20%) were found positive for stx1 gene, and 26 (53.06%) were positive for stx2 gene. In addition, 6 (12.24%) isolates were found positive to both stx1 and stx2 genes, and the remaining 12 (22.46%) were negative. The high prevalence ofSTEC in the broiler chicken alarms the public health impact as the people are always in close contact with these live broiler chickens in the open market as well as processing of meat at home before cooking. However, further studies are required to uncover the major source(s) for the transmission of STEC to human in ruralBangladesh.

Effect of supplementation of yeast with bacteriocin and Lactobacillus culture on growth performance, cecal fermentation, microbiota composition, and blood characteristics in broiler chickens.

ObjectiveThe aim of the present study was to investigate the effect of yeast with bacteriocin and Lactobacillus cultures (mixture of Lactobacillus agilis BCRC 10436 and Lactobacillus reuteri BCRC 17476) supplements, alone or in combination, on broiler chicken performance.MethodsA total of 300, 1-d-old healthy broiler chickens were randomly divided into five treatment groups: i) basal diet (control), ii) basal diet+0.25% yeast (Saccharomyces cerevisiae) (YC), iii) basal diet+0.25% yeast with bacteriocin (BA), iv) basal diet+Lactobacillus cultures (LAB), and v) basal diet +0.25% yeast with bacteriocin+Lactobacillus cultures (BA+LAB). Growth performance, cecal microbiota, cecal fermentation products, and blood biochemistry parameters were determined when chickens were 21 and 35 d old.ResultsThe supplementation of YC, BA, and BA+LAB resulted in a significantly better feed conversion rate (FCR) than that of the control group during 1 to 21 d (p<0.05). The LAB supplementation had a significant effect on the presence of Lactobacillus in the ceca at 35 d. None of the supplements had an effect on relative numbers of L. agilis and L. reuter at 21 d, but the BA supplementation resulted in the decrease of both Lactobacillus strains at 35 d. The BA+LAB supplementation resulted in higher short chain fatty acid (SCFA) in the ceca, but LAB supplementation significantly decreased the SCFA at 35 d (p<0.05). All treatments tended to decrease ammonia concentration in the ceca at 21 d, especially in the LAB treatment group. The BA supplementation alone decreased the triacylglycerol (TG) concentration significantly at 21 d (p<0.05), but the synergistic effect of BA and LAB supplementation was required to reduce the TG concentration at 35 d. The YC supplementation tended to increase the plasma cholesterol at 21 d and 35 d. However, the BA supplementation significantly decreased the cholesterol and low density lipoprotein cholesterol level at 35 d. In conclusion, the BA+LAB supplementation was beneficial to body weight gain and FCR of broiler chickens.ConclusionThe effect of BA and LAB supplementation may be a result of the growth of lactic acid bacteria enhancement and physiological characterization of bacteriocin, and it suggests that the BA and LAB supplementation level or Lactobacillus strain selection should be integrated in future supplementation designs.

Incidence and Antimicrobial Susceptibility to Clostridium perfringens in Premarket Broilers in Taiwan.

Clostridium perfringens infection causes subclinical and clinical necrotic enteritis in poultry flocks, and it is estimated to result in US$2 billion of losses worldwide every year. The aims of this study were to determine the incidence, toxin types, and antimicrobial resistance levels to C. perfringens isolated from premarket, 5-wk-old, clinically healthy broiler chickens in Taiwan, and to examine the relationships between intestinal lesions and the numbers of C. perfringens in intestinal contents. In total, 435 samples of chicken ileum contents were collected from 98 broiler farms during June 2012 to February 2013. The C. perfringens isolation rate was 9.9% (43/435). The positive rate of tested farms was 29.6% (29/98). All the isolates were C. perfringens type A, only possessing the cpa gene encoding for toxin α. No netB gene encoding NetB toxin associated with necrotic enteritis, and no cpe gene encoding for the C. perfringens enterotoxin causing human intestinal disorder were detected. A quantitative PCR analysis revealed that the mean C. perfringens number in the intestinal contents was 3.9 × 10(6) colony-forming units (CFU)/g, ranging from 6.85 × 10(2) to 1.61 × 10(7) CFU/g. The gross and histopathologic lesions revealed a positive correlation (p < 0.05) between lesion score and C. perfringens number in the ilea of C. perfringens -positive chickens. Antimicrobial susceptibility tests of all C. perfringens isolates indicated that the minimum inhibitory concentration inhibiting 50% of isolates (MIC50) for amoxicillin, bacitracin, chlortetracycline, enrofloxacin, erythromycin, florfenicol, and lincomycin was ≤0.125, 0.5, 128, 0.25, ≥256, 2, and ≥256 μg/ml, respectively. Most of the C. perfringens isolates were susceptible to amoxicillin, bacitracin, and enrofloxacin but resistant to chlortetracycline, erythromycin, and lincomycin. Interestingly, C. perfringens isolated from chickens with severe lesions had higher MIC50 for erythromycin and lincomycin than those isolates from chickens with mild lesions. Conclusively, reductions in both the incidence of C. perfringens infection on farms and the concentrations of C. perfringens in intestines to improve broiler health are still needed in Taiwan.

Development of the Intestinal RNA Virus Community of Healthy Broiler Chickens.

Several RNA viruses such as astrovirus, rotavirus, reovirus and parvovirus have been detected in both healthy and diseased commercial poultry flocks. The aim of this study was to characterize (a) the development of the RNA viral community in the small intestines of healthy broiler chickens from hatch through 6 weeks of age (market age) and (b) the contribution of the breeder source vs. bird age in development of the community structure. Intestinal tissue samples were harvested from breeders and their progeny, processed for viral RNA extraction and sequenced using Illumina Hiseq sequencing technology resulting in 100 bp PE reads. The results from this study indicated that the breeder source influenced the RNA viral community only at hatch but later environment i.e. bird age had the more significant effect. The most abundant RNA viral family detected at 2, 4 and 6 weeks of age was Astroviridae, which decreased in abundance with age while the abundance of Picornaviridae increased with age.

Probiotic preparation reduces faecal water genotoxicity and cytotoxicity in chickens fed ochratoxin A contaminated feed (in vivo study).

The aim of the present study was to assess the genotoxicity and cytotoxicity of the faecal water of chickens fed ochratoxin A (OTA) contaminated feed with and without probiotic preparation. The study was performed on 20 healthy female Ross broiler chickens divided into 4 groups: control chickens - fed with non-supplemented feed; PP chickens - fed feed supplemented with the probiotic preparation; OTA chickens - fed feed contaminated with 1 mg per kg of OTA; OTA + PP chickens - fed feed contaminated with 1 mg per kg of OTA and supplemented with the probiotic preparation. Faecal water samples were collected on the 35(th) day of life of chickens from each group. Genotoxicity was measured using the comet assay, and cytotoxicity by means of MTT tests. Mean DNA damage, measured as the percentage of DNA in the tails of the comets, was 8.50 ± 1.10 for chickens fed OTA at 1 mg/kg and 6.41 ± 0.67 in the controls. The supplementation of feed with the probiotic preparation decreased the extent of DNA damage to 4.74 ± 0.78. In the control group of chickens the average cytotoxicity was 38.5 ± 0.5 (in MTT), while in the probiotic preparation group (PP group) it was 31.8 ± 0.7 (in MTT). After supplementation of the feed with the probiotic preparation, the genotoxicity and cytotoxicity were decreased in a statistically significant manner.

Characterization and antimicrobial resistance patterns of Escherichia coli isolated from feces of healthy broiler chickens

ABSTRACT: Avian pathogenic Escherichia coli (APEC) strains are isolated from lesions of poultry presenting colibacillosis, which is a disease that causes either systemic or localized clinical signs. Such strains share many characteristics with E. coli strains that cause extra-intestinal illness in humans. There is not a consensus on how to define the APEC pathotype with regard to the presence of virulence traits. On the other hand, in the past few years, five minimal predictors for APEC detection were proposed. The E. coli isolates in this work were tested through polymerase chain reaction (PCR) to the five proposed minimal predictors and cva C. The strains presenting them were categorized as potential APEC. The APEC and non-APEC categories showed high resistance (&gt; 50%) to cephalotin, erythromycin, streptomycin, sulphametoxazol/trimethoprim, ampicillin, and amoxicillin. Potential APEC strains were significantly more resistant to cephalotin (p &lt; 0.05) and neomcycin (p &lt; 0.01) than non-APEC. These latter were significantly more resistant to tetracycline (p &lt; 0.01) than the potential APEC strains. These results demonstrate that feces of poultry present E. coli strains with resistant features, showing or not the potential of causing colibacillosis in poultry. Because APEC and extra-intestinal illness in humans may be similar, these resistant strains are of interest to public health.

Pilot study of long-term anaesthesia in broiler chickens

ObjectiveTo provide stable anaesthesia of long duration in broiler chickens in order to perform a terminal caecal ligated loop procedure. Study designProspective experimental study. AnimalsSeven clinically healthy broiler chickens (Gallus domesticus) aged 27-36 days, weighing 884-2000 g. MethodsAnaesthesia was induced and maintained with isoflurane in oxygen. All birds underwent intermittent positive pressure ventilation for the duration. End-tidal carbon dioxide, peripheral haemoglobin oxygen saturation, heart rate and oesophageal temperature were monitored continuously. All birds received intraosseous fluids. Butorphanol (2 mg kg−1) was administered intramuscularly at two hourly intervals. Euthanasia by parenteral pentobarbitone was performed at the end of procedure. ResultsStable anaesthesia was maintained in four chickens for durations ranging from 435 to 510 minutes. One bird died and one was euthanized after 130 and 330 minutes, respectively, owing to surgical complications and another died from anaesthetic complication after 285 minutes. Conclusions and clinical relevanceLong-term, stable anaesthesia is possible in clinically healthy chickens, provided complications such as hypothermia and hypoventilation are addressed and vital signs are carefully monitored. There are no known previous reports describing monitored, controlled anaesthesia of this duration in chickens.

Prevalence of E.Coli in broiler chickens in winter and summer seasons by application of PCR with its antibiogram pattern

A total of 205 chicken samples from apparently healthy broiler chickens (35 and 30), diseased broilerchickens (35 and 30) and freshly dead ones (35 and 40) were collected in winter (from December toFebruary) and summer (from June to August) seasons, respectively from Menofyiea government. Theresults showed that the incidence of E.coli in apparently healthy broiler chickens was 15.7%, diseasedbroiler chickens 37.1% and in freshly dead ones 55% in winter season while in summer season was15.8% in apparently healthy, 17.5% in diseased broiler chickens and 18.7% in freshly dead one. Theserogroups of E.coli that obtained by serological identification were O128, O78, O111, O124, O55, O142, O114,O2 and O1. The results of antibiotic sensitivity test for isolated E.coli showed that the isolated E.coliwere highly sensitive for norfloxacin (60%), gentamycin(50%) , neomycin (50%) , streptomycin(50%)and chloramphenicol (50%). moderately sensitive for doxcyclin (10%) and erythromycin(40%) andhighly resistant for amoxacillin /clavulinic acid (0%). The results of multiplex PCR showed that eae A(intimin or E.coli attaching and effacing) gene detected in O128,O55, O1and O2, OmpA (outer membraneprotein ) gene detected in all E.coli serogroups that isolated , stx1 gene not detected in all E. colisergroups that isolated ,but stx2 gene detected in O114 and O128.

Morphometric properties and distribution of alpha-actin in the smooth muscle cells (ASMA) of the small intestine during development in chicken

ABSTRACTThe objective of this study was to investigate the morphological characteristics and expression of the α-smooth muscle actin (ASMA) immunohistochemistry during development of the small intestine in broiler chickens. Twenty-four healthy broiler chickens (ROSS 308) in 4 different age groups (6-, 14-, 28- and 52-day-old) were used in this experiment. A slight increase was observed in the weight and length of the duodenum, jejunum and ileum from days 6 to 28, peaked on day 52. The weight and length of jejunum on days 28 and 52, respectively, were significantly higher in female chickens compared with males (P < .05). An increase in height and width of propria and muscular layers of villi were obtained for the three segments during the experimental period. Villi height and width of jejunum in female broilers at day 28 were significantly larger than males (P < .05). These results also revealed that all the smooth muscle layers were immunoreactive positive for ASMA; but this reactivity differed between the muscle layers. The minimal expression of ASMA was observed at days 6 and 14 of age in circular and longitudinal muscular layers. At day 28, there was a more distinct expression of ASMA in circular and longitudinal muscular layers compared with days 6 and 14. Expression of ASMA in both muscle layers at day 52 was intensely immunopositive. Contractile function during the evolution of each organ and muscle layers could be dependent on different patterns of expression of ASMA in the smooth muscle cells.

Ultrastructural identification of telocytes in the muscularis of chicken ileum.

Telocytes (TCs) are a specialized type of interstitial cells, characterized by a small cell body and long, thin processes, that have recently been identified in various cavitary and non-cavitary organs of humans and laboratory mammals. Chickens present significant economical and scientific notability; however, ultrastructural identification of TCs remains unclear in birds. The aim of the present study was to describe electron microscopic evidence for the presence of TCs in the chicken gut. The ileum of healthy adult broiler chickens (n=10) was studied by transmission electron microscopy. TCs are characterized by several, long (tens to hundreds of µm) prolongations called telopodes (Tps). Tps, which are below the resolving power of light microscopy, display podomeres (thin segments of ≤0.2 µm) and podoms (dilations accommodating caveolae, mitochondria and endoplasmic reticulum). TCs were observed in every field, but were predominantly located in the myenteric plexus and the lamina propria. Tps frequently establish close spatial relationships with immune cells, blood vessels and nerve endings. On the basis of their distribution and morphology, it was hypothesized that the different locations of TCs may be associated with different roles.