Unabsorbed Yolk Sac Research Articles

The Effect of Mycotoxins in naturally Contaminated Diet on the Pathogenicity of Escherichia coli in Broiler Chickens

Contamination of feedstuffs with mycotoxins is considered a huge issue plaguing the poultry sector of Egypt. Therefore, the current study was conducted to examine the effect of the neglected natural mycotoxin contamination of ration on the clinicopathological picture of Escherichia coli infection in broiler chickens. A total of 240 one-day-old chicks were divided into 5 groups. The first 3 groups (1, 2, and 3) were further equally subdivided into 2 subgroups (A and B). Those in group A were fed on commercial ration treated with antimycotoxin while group B was fed on ration contaminated with mycotoxins. Groups 1, 2, and 3 were inoculated at one-day-old with E. coli O78, O128, and O157, respectively while group 4 was kept as a negative control and fed on a ration treated with antimycotoxin. Finally, group 5 was kept as positive controls and fed on a mycotoxin contaminated ration and inoculated with physiological saline. All groups contained 30 chicks. Results showed that the challenged groups fed on a ration containing mycotoxin had high mortality (23.3%) and also a high feed conversion ratio. Moreover, severe clinical symptoms, postmortem lesions, histopathological pictures, and a high rate of bacterial re-isolation were recorded. The pathological lesions were congestion of the liver, spleen, and kidneys in addition to severe pericarditis, perihepatitis, air sacullitis, ascites, and unabsorbed yolk sac. The histopathological changes included degeneration, necrosis, and liver inflammation with lymphoid depletion in the spleen and enteritis associated with sloughing of the mucosal epithelium. The obtained results were less severe in the challenged groups fed on a ration treated with antimycotoxin indicating combined action of both Escherichia coli and mycotoxins. In conclusion, the obtained results revealed that the mycotoxins even at low concentrations can augment the pathogenisity of Echerichia coli in broiler chickens.

Investigating the effects of nest shading on the green turtle (Chelonia mydas) hatchling phenotype in the Ogasawara islands using a field-based split clutch experiment.

The Ogasawara Islands are an important rookery for the green turtle (Chelonia mydas) in the North Pacific. Green turtles possess temperature-dependent sex determination, and warmer incubation temperatures produce more females than males. Therefore, conservation practices such as nest shading may be required for this population to mitigate the effect of global warming on their sex ratio. To consider the application of such conservation practices in the Ogasawara population, it is fundamental to understand how artificially modified nest environments will affect green turtle hatchling phenotypes that influence their fitness. Here, we investigated the effects of nest shading on green turtle hatchling phenotypes in the Ogasawara population by using a split clutch experimentequally separating the clutch, relocating each half-clutch into an outdoor hatchery area either with or without shading, and observing the subsequent hatchling phenotype. Our results showed that the shading treatment produced hatchlings with a better self-righting response and a larger carapace size. Additionally, the shading treatment mostly reduced the production of hatchlings with a nonmodal scute pattern and produced hatchlings with a smaller unabsorbed yolk sac, which may be associated with their residual yolk mass. These results suggest that conservation practices such as shading could alter not only the sex ratio but also the hatchling phenotype that influences their fitness. Hence, our results suggest that applications of such conservation strategies must be carefully considered.

Studies on Pseudomonas aeruginosa Infection in Hatcheries and Chicken

The aim of this work was to spot light on the presence of Pseudomonas aeruginosa (P. aeruginosa) strains in hatcheries and dead in shell embryos. A total of 406 samples representing 200 and 206 swabs from hatcheries environment and yolk sacs of dead in shell embryos were collected from Damietta governorate, Egypt. P. aeruginosa was isolated and identified. Some virulent genes (toxA, psIA and fliC) of P. aeruginosa were detected using polymerase chain reaction (PCR). The antimicrobial susceptibility of P. aeruginosa was tested in vitro. Day and 11 days old broiler chicks were challenged with P. aeruginosa to determine the pathogenicity of the isolated strains. The results showed that P. aeruginosa was recovered from 16 (8%) out of 200 hatcheries and from 17 (8.25%) out of 206 chicken embryos samples. Isolated strains of P. aeruginosa showed presence of toxA, psIA and fliC virulent genes. P. aeruginosa strains were sensitive (100%) to ciprofloxacin, levofloxacin and gentamycin but resistant (100%) to amoxycillin/clavulanic acid, doxycycline and erythromycin. The pathogenicity test of day and 11 days old chicks revealed that P. aeruginosa was highly pathogenic induced mortality rates of 72 and 40%, respectively. Septicaemia of internal organs, unabsorbed yolk sacs, pneumonia, greenish exudates in the abdominal cavity, liver necrosis and enteritis were the predominant lesions. Histopathological changes supported the previous lesions. In conclusion, P. aeruginosa is of great importance pathogen of embryos and newly hatched chicks based on presence of virulent genes as well as in vivo pathogenicity study; respectively.

DETECTION OF ANTIBIOTICS RESISTANCE GENES IN STAPHYLOCOCCUS AUREUS ISOLATED FROM POULTRY FARMS

Poultry industry in Egypt was subjected to various problems one of them was the early chick mortalities that cause great economic losses and its investigation is the request of many poultry scientists and men. In poultry staphylococci, including Staphylococcus aureus are known to cause various diseases from acute septicemia to chronic osteomyelitis. Two hundred and sixty samples of chickens, ducks and turkeys were collected from different poultry farms. A survey on Staphylococcal infection among chickens, ducks and turkeys was carried out. It was found that out of 260 infected and dead chickens, ducks and turkeys suspected to be infected with Staphylococcosis, 54 cases (20.76%) revealed Staphylococcus micro-organisms. The isolated strains were typed as: Staphylococcus aureus (74.07%), Staphylococcus epidermidis (14.8 %)and Staphylococcus saprophyticus (11%). The results of sensitivity biogram revealed that S. aureus were highly sensitive to Amoxicillin, Ampicillin, Ciprofloxacine, Enrofloxacine and lincomycin and resistant to Erythromycin, Streptomycine and Chloramphenicol. The results of MIC of 6 representative coagulase positive Staphylococci isolates against 6 selected antibiotics commonly used in poultry farms showed that 100% of isolates were sensitive to amoxicillin, enrofloxacin, ciprofloxacin and oxytetracyclin, while 100% of 6 isolates were resistant to streptomycin and lincomycin. The incidence of isolation of Staphylococci from the internal organs of examined birds and from unabsorbed yolk sac, joints, liver, intestinal content and heart blood was 36.3%, 20%, 19.2%, 17.3% and 16.9% respectively. Ten of each detected isolates were examined by cPCR for resistance genes blaZ and aac(6’) aph (2’’). The isolates harbored these resistance genes with percentage of 100% for S. aureus. In experiment, the pathogenicity of the isolated strains of S. aureus for 7 day- old chicks was studied. S. aureus injected subcutaneously, oral and intranasal caused death of 100%, 100% and 26.7% of the used chicks respectively.

ANTIMICROBIAL SUSCEPTIBILITY TO SALMONELLA AND E.COLI ISOLATES ORIGINATED FROM BROILER CHICKENS IN LUXOR GOVERNORATE

Salmonellosis and colibacillosis are continuing serious problems facing poultry industry in Egypt. In this study, 300 different pooled broiler chickens organs samples as (trachea, lung, liver, heart, spleen, unabsorbed yolk sac and intestine) were collected from different apparently healthy and sick broiler flocks in different localities of Luxor governorate during (2015 and 2016). The examined broiler flocks were suffering from various health problems developed during the final two weeks of the growing period, resulting in increased mortality and condemnation losses. Bacterial isolation was done by using standard method of isolation and identification. The results showed that 92 out of 300 broiler organs samples were positive for Salmonella spp. (30.66%) while 161 out of 300 were E.coli positive (53.66%). The present study showed that the main Salmonella spp. isolates were (S. Typhimurium (24%), the both of S. Enteritidis, S. Anatum were (21.7%) and S. Kentucky (19.56%), S. Bargny and S. Molade (3.26%) then S. Newport, S. Ingada and S. Agona their percentage were (2.17%) respectively, while 8 serotypes of E.coli were obtained with the following serological identification O78 (44%), O1:H7 (17.39%), O91:H21 (15.52%), O128:H2 (13%) and other E.coli serotypes were identified as (O2:H6, O26:H11, O55:H7, O146:H21) their percentage was (1:3%). Bacterial strains were tested against 21 antibacterial agents using the standard disk diffusion method on Muller and Hinton’s Agar medium. The results were recorded that most of Salmonella spp were highly resistant to (Oxytetracycline, Doxycycline, Tetracycline then Enrofloxacin, Sulphamethoxazole) and were sensitive to (Gentamycin, colistinsulphate and Ceftiofur). While most of E.coli isolates were resistant to Neomycin and Streptomycin and were sensitive to Ceftiofur then Colistinsulphate.

English

A study was conducted from November 2014 to June 2015 at three hatcheries designated as A, D and E in Bishoftu Town, Ethiopia, to isolate and identify bacteria associated with yolk sac infection and to determine antimicrobial susceptibility profile of the predominant isolates. A total of 385 Lohmann and Koekoek breed, 1 to 7 days old chicks suffering from yolk sac infection were examined from three different hatcheries of which 96.1% (N=370) of them were showing unabsorbed yolk sac. All the chicks were necropsied and yolk sac samples were collected for isolation and identification of bacteria followed by testing of the isolates for their susceptibility to 11 antimicrobial agents using disc diffusion method. A total of 323 bacterial isolates were identified, of these Escherichia coli were the most common bacteria (N=116; 35.91%) isolated followed by Salmonella species (N=111; 34.36%) and Staphylococcus aureus (N=96; 29.72%). Significant difference (P<0.001) was noted among the hatcheries on the frequency of isolation of the predominant bacteria species from yolk sac samples with the highest rate of isolation being in hatchery A. All the tested predominant bacterial isolates showed higher susceptibility to Gentamicin, Chloramphenicol, Amikacin (except S. aureus) and Kanamycin but were resistant to Ciprofloxacin, (except S. aureus), Penicillin G, Tetracycline, Sulfamethoxazole  and Amoxicillin (except S. aureus). The existence of multi-drug resistant bacteria isolates associated with yolk sac infection suggests that more emphasis should be given towards preventing omphalitis in chicks through improvements of sanitary measures at hatcheries than to use antimicrobials to control infections.   Key words:  Bacteria, chicken, yolk sac infection, antimicrobial sensitivity, Ethiopia.

Phenotypic and Genotypic Characterization of Paratyphoid Salmonellae isolated from Poultry in Delta Area- Egypt

The present work aimed to isolate and characterize Salmonellae from chickens, ducks, quails and turkeys in five Egyptian Governorates. Polymerase chain reaction (PCR) was used for the detection of common virulence genes. A total of 265 flock samples (150 chickens, 60 ducks, 30 quails and 25 turkeys) were collected from Dakahlia, Kafrelsheik, Damietta, Sharkia and Gharbia Governorates. Birds were subjected to either clinical and/or post-mortem examination, in adittion to isolation and identification of salmonellae from internal organs including liver, lung, spleen, caecum and unabsorbed yolk sac. Biochmeical and serological identification of the isolates was done. Twenty eight birds (10.6%) were found positive for Salmonella isolation. The number and percentage of positive chickens, ducks, quails and turkeys were 16 (10.7%), 7 (11.7%), 3 (10%) and 2 (8%), respectively. Salmonella Typhimurium, S. Enteritidis, S. Kentucky, S. Paratyphi A, S. Molade, S. Heidelberg, S. Infantis and S. Apeyeme were isolated from chickens. While S. Enteritidis, S. Typhimurium, S. Paratyphi A, S. Kentucky, S. Inganda and S. Bargny were isolated from ducks. While, S. Virchow, S. Tamale and S. Typhimurium were isolated from Quails and S. Wingrove, finally, S. Kentucky were isolated from turkeys. Molecular characterization of common virulence genes Salmonella outer proteins (sopB), Plasmid encoded virulence gene (spvC), salmonella enterotoxin (stn) and bacterial colonization factor (bcfC) showed the presence of stn and bcfC genes in all isolates, while, sopB and Spv genes were present in 64.3% and 10.7%, respectively. It is concluded that salmonellae with common virulence genes were widely spread among domestic birds in Delta areas, Egypt, resulting in economic and public health problems which require the application of strictly biosecurity measures in poultry rearing.

THE ROLE OF SALMONELLA SPECIES AS A CAUSE OF OMPHALITIS IN BABY CHICKS IN ASSIUT GOVERNORATE

A total of 130 diseased and dead broiler chicks of 1-10 days of age obtained from different sources were examined; yolk sac samples from these chicks were cultured and the bacteria were isolated and identified on biochemical tests. Unabsorbed yolk sac was observed in 48 (36.9%) chicks associated with signs of septicemia in many cases. These unabsorbed yolk sac exhibit signs of moderate to mild inflammation indicating that the cause of death is the consequences of the infection rather than it's direct effect. The recovered 12 Salmonella isolates were: S. enteritidis 5(41.6%), S.virchow 3(25%), S.typhimurium 2(16.6%), S.heidelberg 1 (8.3%), S. kentucky 1(8.3%). Thickness of yolk sac wall and the fibroses may be the cause of un absorption of yolk, Sever changes were seen in the liver, heart, intestine and yolk sac represented by congestion, inflammatory cells infiltration.

Frequency of Occurrence of Physical Defects in Turkey Poults / Częstotliwość występowania wad budowy piskląt indyczych

Abstract The objective of this study was to determine poult quality in the first breeding season of turkeys. The study was conducted over a 24-week laying season of white broad-breasted Big 6 turkeys. Starting from the first week of laying, at three-week intervals, 504 eggs laid on the same day were weighed and the percentages of eggs weighing 70 to 100 g and more than 100 g were calculated. Results from the 21st week of laying season were not used due to failure of ventilation equipment. Each egg was visually inspected to determine the percentages of eggs with normal shell structure, rough-shelled eggs and eggs without shell pigmentation. Nine incubation cycles were carried out. Egg fertilization rates and hatch rates were determined. At the end of each incubation cycle, poults were weighed individually and divided into morphologically normal and morphologically defective. The latter were further subdivided into weak poults with poor motor skills, poults with abnormal feathers, eyes, legs and umbilicus, and poults with unabsorbed yolk sacs. Eggs with weight exceeding 100 g accounted for 17.9% and 46.6% of the analysed eggs at 12 and 24 weeks of the laying season, respectively. In week 12, eggs without shell pigmentation accounted for 8.3%. In week 24, the percentage of rough-shelled eggs was 6.7%. Most poults with physical defects hatched in weeks 1 and 3 of the laying period (65.67% and 76.84%, respectively). Weak poults with poor motor skills accounted for 0.2-2.5% of the examined birds. Wet feathers were noted in 0.9% to 4.1% of poults over the laying season. Leg abnormalities were observed in 6.5% to 7.8% of poults. Eye defects were encountered least frequently. In 41-70% of poults long black scabs were visible on their navels, and umbilical vessels were long. Unabsorbed yolk sacs were noted in 0.5% to 3.2% of poults.

Natural Occurrence of Campylobacter Species, Salmonella Serovars, and Other Bacteria in Unabsorbed Yolks of Market-Age Commercial Broilers

In the developing avian embryo, the main energy source is the yolk. Toward the end of the incubation period, the remaining yolk sac is internalized into the abdominal cavity. At hatch, the remaining yolk comprises 20% of the chick's BW and provides the nutrients needed for maintenance. Posthatch, chicks rapidly initiate the transition from yolk dependence to the utilization of exogenous feed. However, at present, it is not known what types of bacteria are found to be associated with unabsorbed yolk sacs from market-age broilers. For Experiment 1, one hundred 6-wk-old defeathered broiler carcasses were obtained from a commercial processing facility during each of 3 visits. In the second experiment, one hundred 8-wk-old defeathered broiler carcasses were obtained from a different commercial processing plant on 4 separate occasions. For both experiments, each carcass was aseptically opened and inspected for the presence of an unabsorbed yolk sac. Three to 5 carcasses containing a free-floating yolk sac (within the abdominal cavity) and the yolk stalk (without a yolk sac) and 3 to 5 carcasses containing an attached yolk and yolk stalk from each repetition were randomly selected and analyzed for levels and types of total aerobic bacteria (APC), Enterobacteriaceae (ENT), and for the presence of Campylobacter spp. and Salmonella serovars. The APC ranged from log 3.3 to >log 6.0, and the ENT ranged from log 2.8 to >log 6.0. Staphylococcus spp. and Streptococcus spp. were the predominant organisms in APC, whereas Escherichia coli and Hafnia alvei were found to comprise the ENT. Campylobacter spp. was found in 29% of the yolk stalks, 32% of the attached yolk sacs, and 13% of the free-floating yolk sacs. All Campylobacter isolates were determined to be Campylobacter jejuni, except for 1 attached yolk and yolk stalk, which was Campylobacter coli. Salmonella serovars were found in 26% of the yolk stalks, 48% of the attached yolk sacs, and 23% of the free-floating yolk sacs, and the majority of Salmonella isolates were Salmonella Typhimurium. The significance of these bacterial reservoirs and carcass contamination during processing is yet to be determined.

Influence of Water Provision to Chicks Before Placement and Effects on Performance and Incidence of Unabsorbed Yolk Sacs

A study was conducted to determine the effect of water provision to chicks before placement on performance and the incidence of unabsorbed yolk sacs. To accomplish this, a device was used that was designed to deliver water to chicks in chick baskets during holding at the hatchery and transportation to the growout house. Commercial chicks were obtained from the hatchery and held for either 24 or 48 h with or without access to water before placement. Chicks were then distributed into floor pens with ad libitum access to feed and water. At 6 wk of age, broilers were processed, and intestines were evaluated for presence or absence of an unabsorbed yolk sac and intestinal breaking strength. Body weight at placement was 2 to 6 g greater for chicks given access to water; however, this difference was not observed at any other time during the growout. Water provision during holding had no affect on feed consumption, mortality, or the birds’ ability to completely absorb the yolk sac during the 6 wk growout. Incidence of unabsorbed yolk sacs in 6 wk old birds ranged from 15 to 28%. Moreover, presence or absence of an unabsorbed yolk sac had no effect on intestinal breaking strength. Data from the present study demonstrates that providing chicks with water before placement does not influence performance, intestinal breaking strength, or the incidence of unabsorbed yolk sacs.

Incidence of unabsorbed yolk sacs in broilers, broiler breeder roosters, white Leghorn hens, and Athens-Canadian randombred control broilers

Unabsorbed yolk sacs are being investigated as a possible reservoir for internal Campylobacter and salmonellae contamination of processed poultry carcasses. However, it is unknown at what frequency that unabsorbed yolk sacs persist at the time of processing of broilers and spent breeders. Seven sets of 100 broiler carcasses (at 6 or 8 wk of age) were obtained from commercial processing plants. In addition, 100 52-wk-old broiler breeder males, 100 102-wk-old Leghorn hens, and 300 8-wk-old Athens-Canadian randombred control (ACRBC) broilers were euthanized, and their abdominal cavities were opened for determination of the presence of unabsorbed yolk sacs. Carcasses with obliterated yolk stalks or stalks with no detectable yolk material were categorized as normal. Those with unabsorbed yolk sacs were further separated into 2 groups: 1) attached by the yolk stalk to the small intestine or 2) unattached within the abdominal cavity. Yolk sacs were further classified by size: 1) small was <2 mm in diameter, 2) medium was 2 to 10 mm, and 3) large was >10 mm. From the 300 commercial broiler carcasses that were 6 wk old, 54% were categorized as normal with no detectable yolk sac, 35% had an unabsorbed yolk sac attached to the yolk stalk, and 12% had unattached yolk sacs. From the 400 commercial broiler carcasses that were 8 wk old, 49% of the carcasses were normal, 31% had attached unabsorbed yolk sacs, and 20% had unattached yolk sacs. From the 100 rooster carcasses sampled, 73% were normal, 8% had attached unabsorbed yolk sacs, and 19% had unattached yolk sacs. From the 100 White Leghorn hen carcasses sampled, 88% were normal, 8% had attached unabsorbed yolk sacs, and 4% were unattached yolk sacs. From the 300 ACRBC carcasses sampled, 76% were normal, 4% had attached unabsorbed yolk sacs, and 20% were unattached yolk sacs. The incidence of unabsorbed yolk sacs in present day commercial broilers appears twice as high as for mature roosters, hens, or ACRBC broilers.

Yolk sac utilization in ostrich (&lt;i&gt;Struthio camelus&lt;i/&gt;) chicks : research communication

The mass of residual yolk sac expressed as a percentage of initial mass of the egg from which the chick hatched decreased sharply in the first 2 days post-hatching. A gradual reduction occurred between 3 and 10 days after which a sharp decline was noted between 11 and 13 days post-hatching. The highest number of chicks with unabsorbed yolk sac was noted on day 5 post-hatching followed by days 6 and 7. Chick mortality followed the same pattern. The dynamics, causes and clinical consequences of yolk sac utilization are discussed.

Yolk sac infection in a broiler flock: a case report

A case of yolk sac infection is reported among 500 broiler chicks bought for National Root Crop Research Institute, Umudike, Poultry Project. From the day of receipt the birds were depressed, dull with distended abdomen. The next day and subsequent days the birds started dying, reached its peak on the 12th day with 8 deaths. Result of post mortem done on the dead chicks revealed a septicaemic carcass with the subcutaneous and yolk sac blood vessels enlarged and dilated. The striking feature was an inflamed unabsorbed yolk sac with the yolk abnormal in colour and consistency. Post mortem findings seen in chicks that survived into second, third and forth weeks were inspissated yolk sac which contained deeply pigmented caseous material. Bacteriological isolations revealed the presence of Escherichia coli. The outbreak was presumed to be as a result of Escherichia coli contaminating the hatching eggs and further penetrate the shell to infect the yolk. The source of infection was found to be from the hatchery contaminated with Escherichia coli where infection spread from chick to chick. KEY WORDS: Yolk Sac Infection, Broiler Flocks, Septicaemic Carcass. (Nigerian Veterinary Journal: 2002 23(2): 65-69)

Effect of low and high doses of Salmonella enteritidis PT4 on experimentally infected chicks.

Chicks (1-d-old, three groups, each containing 50 chicks) were inoculated with 2 x 10(2) and 2 x 10(8) CFU of Salmonella enteritidis; the third group were kept as uninoculated control. Five birds from each group were euthanized at intervals from 6 h to 4 weeks post-inoculation (pi). In the low-dose group S. enteritidis was isolated from 60% cecal samples at 18 h pi, and from 20% of livers at 3 d pi. Individual variation in the frequency of S. enteritidis recovery was observed in this group. The clearance of salmonella from the organs was faster in the low-dose group, and salmonella was not isolated from the liver and cecum at 21 and at 27 d pi, respectively. However, in the high-dose group, S. enteritidis was isolated from all ceca and 80% of liver 6 h pi, and salmonella was detected in the cecum and liver throughout the experiment. Serous typhlitis and unabsorbed yolk sac were the most prevalent lesions in both groups. Granulomatous nodules in the cecum were found occasionally in some cases in both inoculated groups, which can play a role as reservoirs in carrier chicks.

Time Course Evaluation of Carotenoid and Retinol Concentrations in Posthatch Chick Tissue

Carotenoid and retinol concentrations were determined in chicks hatched from carotenoid-enriched eggs while being fed a carotenoid free starter diet. Single Comb White Leghorn (SCWL) hatching eggs were obtained from breeder hens fed diets enriched with either 0.2% β-carotene, canthaxanthin, lutein, or basal control. Twenty-five day-old chicks hatched from each treatment group were placed in a battery and fed a carotenoid-free basal diet. At 1, 4, 7, 10, and 13 d, five chicks per treatment were randomly selected, and blood serum, liver, and unabsorbed yolk sac were collected for carotenoid and retinol analysis. There were no significant differences in retinol concentrations in the serum, liver, and unabsorbed yolk sac of the chickens. Only small amounts of β-carotene were detected in the chick tissues. Concentration of all three carotenoids and retinol were greater in the liver and unabsorbed yolk sac than in serum. In the serum and liver, respective carotenoid concentrations decreased and retinol concentration increased with increasing age, whereas respective carotenoid and retinol concentrations in the unabsorbed yolk sac increased over time. It may be concluded that yolk sac carotenoids are not absorbed well, as unabsorbed yolk sac concentrations increased over time, and that carotenoid in serum and liver decrease linearly with increasing age.

Experimental infection of chicks withArizona hinshawii

One-day old chicks were infected with an Arizona hinshawii organism either subcutaneously or orally. Fifty two percent of the subcutaneously infected but none of the orally infected birds died within 10 days of infection. The incubation period ranged from 20 hours to 12 days. Symptoms of pasty vent, opacity of the lens of one or both eyes, tremors of the head, opisthotonous, twisting of the neck and paresis in the legs were observed. Postmortem examination of dead birds revealed septicaemia, enlargement of the gall bladder, engorgement of the ureters with urates and unabsorbed yolk sac. The inoculated organism could be recovered from the internal organs of all dead birds. Shedding of arizona in the faeces of infected birds continued up to the 28th and 49th day after infection in the subcutaneously- and orally-infected birds respectively. Results of the microagglutination test revealed that 71.4% of the subcutaneously and 55% of the orally infected birds had detectable agglutinins in the period from the 4th to the 8th week after infection.