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Coccidiosis, the parasitic disease caused by Eimeria spp., is controlled during broiler chicken production through the inclusion of in-feed anticoccidial medications. Live-coccidiosis vaccination has become an increasingly common alternative to these medications. Monitoring infections with Eimeria spp. in flocks can be accomplished through determining the concentration of oocysts excreted in the fecal material (i.e., oocysts per gram; OPG). The purpose of our study was to sample commercial Ontario broiler chicken flocks at various times of the year to determine weekly OPG counts for flocks that use either an in-feed anticoccidial medication or a live-coccidiosis vaccine. Weekly sampling of 95 flocks from placement to market permitted documentation of oocyst cycling patterns typical of conventional and antibiotic-free flocks, and variation of these patterns in summer and winter. Medicated flocks had higher and later peak oocyst shedding compared with vaccinated flocks. Flocks reared in the summer peaked in oocyst shedding earlier than flocks reared in the winter. Despite what appears to be poorer coccidiosis control in the medicated flocks, the performance data were similar for these flocks compared with vaccinated flocks. This is the first study describing typical patterns of parasite shedding in Ontarian commercial broiler chicken flocks; these data will provide a baseline of expected Eimeria spp. infections in Canadian broiler chicken flocks to ensure optimal coccidiosis prevention.

The Canadian Food Inspection Agency is developing an Establishment-based Risk Assessment model for Hatcheries to allocate inspection resources according to the food safety risk associated with each hatchery falling under its jurisdiction. In a previous study, 29 factors contributing to the food safety risk of hatcheries were identified and grouped into three clusters (inherent risk, risk mitigation, and compliance) and assessment criteria were defined. The objective of the current study was to estimate the relative risk (RR) of these criteria. Two rounds of expert elicitations were conducted to allow 13 Canadian experts to estimate the RR of each criterion (

Due to genetic selection for fast growth and high breast meat yield, commercial strains of broiler chickens and broiler breeders are predisposed to high feed intake; however, feeding broiler breeders ad libitum impairs their health and reproductive performance. Broiler breeders are feed-restricted throughout rearing to maintain health and performance, yet feed restriction results in hunger, feeding frustration and lack of satiety. The objective of this study was to examine the effect of alternative feeding strategies, including feed additives (separately or combined) and a fixed non-daily feeding schedule, on the feeding motivation and welfare of broiler breeders during rearing. At 3 weeks of age, 180 Ross 308 breeder pullets were allocated to 90 cages and fed with one of five isocaloric treatments: (1) daily control diet (control), (2) daily calcium propionate diet (CaP), (3) daily soybean hull diet (SBH), (4) daily alternative diet (alternative: CaP + SBH) and (5) 4/3 control diet (four on-feed days and three non-consecutive off-feed days per week). The CaP diet included calcium propionate at 1.4% from 3 to 6 weeks of age, and at 3.2% from 7 to 12 weeks of age, and the SBH diet contained soybean hulls included at 40%. The alternative diet included both soybean hulls and calcium propionate at the same inclusion rate as the SBH and CaP diets, respectively. Pullets were weighed and scored for feather coverage every week. A feed intake test was conducted at 3, 4, 8, 10 and 11 weeks of age for 10 min during on- and off-feed days. At 12 weeks of age, feather samples were analysed for fault bars. Data were analysed using linear mixed regression models, with cage nested in the models and age as a repeated measure. At 4 weeks of age, pullets fed soybean hull-enriched diets (SBH and alternative diets) and those on the 4/3 schedule had lower feed intake than control pullets (P = 0.02). Feathers from pullets fed the SBH diet had fewer fault bars than those fed the CaP diet (P = 0.04). The results indicated that the inclusion of soybean hulls (alone or combined with calcium propionate) and a 4/3 feeding schedule can reduce feeding motivation of broiler breeders during early rearing.

Salmonella enterica and Escherichia coli are bacteria of concern to veterinary public health and poultry health. Our research aimed to determine the factors associated with S. enterica and E. coli in commercial broiler chicken barns during the rest period between flocks to identify the best methods of sanitation for bacterial load reduction. This involved collecting samples from September 2015 to July 2016 from the floors of 36 barns before sanitation (baseline) and at 2 time intervals after sanitation, followed by microbiological and molecular analysis. A priori variables of interest included sanitation procedure (dry cleaning, wet cleaning, disinfection), sampling point (baseline, 2 d after sanitation, 6 d after sanitation), and flooring type (concrete, wood). The odds of detecting S. enterica were higher on wooden floors that were wet-cleaned than on concrete floors that were dry-cleaned, lower in the winter and spring than in the fall, and lower when samples were collected 2 d and 6 d after sanitation than at baseline. For E. coli, the concentration was higher on wooden floors than on concrete floors and in the summer than in the fall, and it was lower in postsanitation samples from disinfected barns than in presanitation samples from dry-cleaned barns and in the winter than in the fall. Among E. coli isolates, factors associated with the presence of qacEΔ1, a gene associated with resistance to quaternary ammonium compounds, included sanitation procedure, flooring type, cycle length, and the number of times per yr the barn is disinfected. Our findings highlight the importance of cleaning after litter removal, although the sanitation procedure chosen might differ depending on which pathogen is present and causing disease issues; dry cleaning appears to be preferable for S. enterica control, especially in barns with wooden floors, whereas disinfection appears to be preferable for E. coli reduction.

A national baseline study was conducted between December 2012 and December 2013 to determine the pre-packaging prevalence and concentration of foodborne pathogens on broiler chicken carcasses and parts at processing; a survey was implemented simultaneously to collect data on the processing practices used to control these pathogens. Thirty federally-registered Canadian poultry processing establishments completed the questionnaire. A total of 2,732 samples of carcasses and parts (breast and thigh pieces) were collected over the study period from these establishments. For Salmonella, the overall proportion positive was 0.22 (95% CI 0.20, 0.23), and the mean concentration was 0.67 (95% CI 0.51, 0.83) MPN/mL of rinse fluid. Multivariable regression models with random intercepts for the establishment and the date of sampling were used to identify associations between Salmonella prevalence and concentration and processing practices. In the final logistic regression model for the prevalence outcome (positive or negative sample), there were three statistically significant variables: product type (carcass or part); chilling method (water or air); and chlorine use in the establishment (chlorine, cetylpyridinium chloride, or neither). The likelihood of testing positive for Salmonella was higher on parts than carcasses (OR 3.03, 95% CI 2.38, 3.86), and higher when cetylpyridinium chloride was used (OR 2.00, 95% CI 1.36, 2.95), or when other processing aids were used (OR 1.99, 95% CI 1.26, 3.15), than when chlorine was used. Water chilling was negatively associated with testing positive for Salmonella when compared with air chilling (OR 0.68, 95% CI 0.48, 0.96). In the final linear regression model for the concentration outcome (log10 MPN/mL), there was one statistically significant variable chilling method, where water chilling was associated with a decrease in concentration (β -0.23, 95% CI -0.38, -0.08 log10 MPN/mL). The intraclass correlation coefficients for establishment and date sampling were 0.02 and 0.23 in the linear regression model, and 0.01 and 0.34 in the logistic regression model, respectively. Further studies to explore the methods to reduce microbial contamination during the air chilling and cut-up and boning processes in broiler chicken establishments in Canada are recommended.

In Ontario, within the past few years, there has been a marked increase in the number of non-commercial poultry flocks (referred to as “small flocks”). Small poultry flocks may act as a reservoir of avian and zoonotic pathogens, given the flocks’ limited access to veterinary services, inadequate biosecurity practices, and increased risk of contact with wild birds. Despite these potential risks, there is a scarcity of data concerning the prevalence of poultry and zoonotic pathogens among these flocks. To assess the baseline prevalence of bacterial and viral infectious pathogens, prospective surveillance of small flock postmortem submissions to the Animal Health Laboratory was conducted over a 2-y period. With the owner’s consent, a postmortem examination and pre-set tests for infectious agents were conducted. A total of 160 submissions, mainly chickens (84%), were received. Among bacterial pathogens, Brachyspira spp., Mycoplasma synoviae, Campylobacter spp., Mycoplasma gallisepticum, and Salmonella spp. were detected in 37%, 36%, 35%, 23%, and 3% of tested submissions, respectively. Among viral pathogens, infectious bronchitis virus, fowl adenovirus, infectious laryngotracheitis virus, avian reovirus, and infectious bursal disease virus were detected in 39%, 35%, 15%, 4%, and 1% of submissions, respectively. We detected non-virulent avian avulavirus 1 from two chickens in a single submission, and low-pathogenic H10N8 influenza A virus from a single turkey submission. Our study provides baseline prevalence of viral and bacterial pathogens circulating in Ontario small flocks and may help animal and human health professionals to educate small flock owners about disease prevention.

The accompanying dataset for this article is available at: Santos, Midian N.; Rothschild, Daniel; Widowski, Tina M.; Barbut, Shai; Kiarie, Elijah G.; Mandell, Ira; Guein, Michele T.; Edwards, A. Michelle; Torrey, Stephanie, 2022, "Replication data for: In pursuit of a better broiler: carcass traits and muscle myopathies in conventional and slower-growing strains of broiler chickens", https://doi.org/10.5683/SP3/T36W8L, Scholars Portal Dataverse. Selection for accelerated growth rate and high breast yield in broiler chickens have been associated with an increase in myopathies, including wooden breast (WB) and white striping (WS). To investigate effects of growth rate on carcass traits and incidence of myopathies, 14 strains were evaluated, encompassing 2 conventional(CONV; strains B and C: ADG0-48 > 60 g/d)and 12 slower-growing (SL) strains. The latter were categorized based on growth rate: FAST (strains F, G, I and M; ADG0-62=53−55 g/d), MOD (strains E, H, O and S; ADG0-62=50-51 g/d), and SLOW (strains D, J, K and N; ADG0-62

As part of a 2 yr disease surveillance project of small poultry flocks, owners of birds submitted for postmortem examination to the Animal Health Laboratory were asked to complete a questionnaire designed to gather information on the characteristics of the flock and its environment, how the flock was managed, and biosecurity measures used. A total of 153 unique questionnaires were received. Personal consumption of meat or eggs was the most common reason for owning a small flock (69.3%). Almost all owners (97.4%) reported having chickens on their property, while 21.6% had waterfowl, 15.7% had turkeys, and 15.7% had game birds. Nearly 70% (69.9%) of the flocks had some degree of outdoor access. For those with indoor access, the most common bedding material provided was soft wood shavings (70.2%). Kitchen waste or leftovers were offered to 65.3% of flocks, and well water was the most common source of drinking water (80.6%). For flocks with indoor access, dedicated shoes and clothes were used when entering or cleaning the coop by fewer than half of owners, and shoes were rarely disinfected before or after contact with the flock. Most owners (93.8%) reported washing their hands after contact with their birds, although only 48.3% reported washing their hands before contact. Among owners who sourced birds from a hatchery, only 36.8% indicated that the birds had been vaccinated, and 21.1% were unsure if vaccines had been administered. Among owners using medication (60.5%), the use of antibiotics was common (60.9%). Overall, questionnaire responses describe a wide range of husbandry and biosecurity practices, often suboptimal, and point out the need for educational material for Ontario small flock owners.

Detection of behavioural temporal patterns (T-patterns) allows for insight into the organization of behaviours that is not apparent through quantitative analysis of the durations and frequencies of discrete behaviours. In this study, a T-pattern was defined as a reoccurring sequence of ≥2 behavioural event types 2 linked by a non-random critical period of time and occurring more often than expected by chance. This study aimed to identify differences in the behavioural distribution and organization of two forms of injurious pecking, head pecking (HP) and severe feather pecking (SFP), and non-damaging gentle feather pecking (GFP) in domestic turkeys using two analytical methods T-pattern analysis and a conventional assessment of behavioural frequencies and durations. Video observations of pecking behaviour were obtained from focal samples of domestic male turkeys between 5 and 15 weeks of age. Each focal sampling observation recorded all behaviours shown by a single turkey 120 s (s) before and after the turkey performed HP, GFP, or SFP (241 s total observation length per pecking event). Pecking type had no effect on the number of T-patterns and the frequency of T-pattern occurrences. However, both T-pattern detection and the conventional analysis showed turkeys in observations containing HP tended to be more active with shorter lying durations (H = 7.36, df = 2, P = 0.025), less frequent standing (H = 5.61, df = 2, P = 0.061), and less structured T-patterns (total T-pattern durations: H = 5.996, df = 2, P = 0.050, mean durations: H = 5.34, df = 2, P = 0.068) than turkeys engaged in GFP or SFP. The analyses also showed that turkeys that performed SFP tended to show more frequent GFP than turkeys that performed HP (H = 5.79, df = 2, P = 0.055). However, discrepancies in organization of feeding and foraging behaviour between the two analytical methods highlighted the susceptibility of both methods to behavioural variation between individuals when using small sample sizes. Future research should use T-pattern detection to evaluate age, sex, and environmental differences in the organization of the injurious pecking behaviour in domestic turkeys.

SUMMARY In this study, the simulated hock flexion resistance at which employees could consistently differentiate a stunned bird from a recently dead end-of-lay hen was evaluated. A mechanical apparatus was used with individually weighted levers, ranging in resistance from 66 to 485 gram-force (gf), in a random order. A reference lever was weighted at 120 gf, which is similar to that of stunned birds measured immediately after gas stunning. Each employee (n = 15) lifted each lever to an approximately horizontal plane and designated it as having less resistance or similar resistance to the reference lever (light) or greater resistance than the reference lever (heavy). Dominant and non-dominant hands were tested independently. For resistance of up to 300 gf, there was a significant (P ≤ 0.05) increasing curvilinear trend in the proportion of employees who considered the lever to be heavy, and a significant decreasing curvilinear trend in the proportion who considered the lever to be light. At greater than 300 gf, close to 100% of employees gave the designation heavy, and there was no significant (P > 0.05) change with any further increases in weight. It was concluded that employees could reliably detect hock flexion resistances of ≥ 300 gf as larger in magnitude than 120 gf.

Veterinary care can both positively and negatively impact animal welfare in terms of behavioural welfare. This occurs both in the veterinary clinic through interactions with patients and management of their stress, fear and aggression, and in the animal’s home through the provision of behaviour and training advice for behavioural management as a whole. An animal welfare assessment scheme, incorporating management-, resource- and animal-based measures of animal welfare through interviews and appointment observations, was developed to assess practices related to behavioural welfare in small animal veterinary clinics. It was tested for reliability, validity, and feasibility in 30 companion and mixed animal veterinary clinics, and information concerning current behavioural welfare practices was also collected. Based on weighted kappa statistics, inter-observer reliability showed almost perfect agreement for interview scoring (Kw = 0.82 and 0.81) and substantial agreement for appointment observation scoring (Kw = 0.74 and 0.70); however, at the individual question and handling item level, weighted kappa statistics for inter-observer reliability ranged greatly. Interviews were more feasible to carry out than appointment observations, although discrepancies between interview responses and veterinary staff-patient interactions observed during appointments suggest that interviews might be a less valid measure. Descriptive results suggest that there is enough variability in most assessed areas to allow for differentiation between veterinary clinics on the basis of their behavioural welfare practices. Additional research is required to explore these trends in strengths and areas for improvement in a larger sample of veterinary clinics.

Osteoporosis in laying hens has been a production and welfare concern for several decades. The objective of this study was to determine whether differing opportunities for exercise during pullet rearing influences long-term bone quality characteristics in end-of-lay hens. A secondary objective was to assess whether differing opportunities for exercise in adult housing systems alters bone quality characteristics in end-of-lay hens. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S), or 60-bird furnished cages (FC-L) for adult housing. Wing and leg bones were collected at the end-of-lay to quantify bone composition and strength using quantitative computed tomography and bone breaking strength (BBS). At the end-of-lay, Avi hens had greater total and cortical cross-sectional area (P < 0.05) for the radius and tibia, greater total bone mineral content of the radius (P < 0.001), and greater tibial cortical bone mineral content (P = 0.029) than the Conv hens; however, total bone mineral density of the radius (P < 0.001) and cortical bone mineral density of the radius and tibia (P < 0.001) were greater in the Conv hens. Hens in the FC-L had greater total bone mineral density for the radius and tibia (P

Increased load-bearing exercise improves bone quality characteristics in a variety of species, including laying hens. Providing increased opportunities for exercise during the pullet rearing phase, a period of substantial musculoskeletal growth, offers a proactive approach to reducing osteoporosis by improving bone composition. The main objective of this study was to determine whether differing opportunities for exercise during rearing influences pullet musculoskeletal characteristics. Two flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either standard, conventional cages (Conv) or an aviary rearing system (Avi) from day-old chicks until 16 wk of age. The keel bone and the muscles and long bones of the wings and legs were collected at 16 wk to measure muscle growth differences between rearing treatments and quantify bone quality characteristics using quantitative computed tomography (QCT) and bone breaking strength (BBS) assessment. Keel bone characteristics and muscle weights were adjusted for BW and analyses for QCT and BBS included BW as a covariate. At 16 wk of age, rearing system had an effect on the majority of keel bone characteristics (P < 0.05). The length of the keel metasternum, caudal tip cartilage length, and the overall percentage of cartilage present on the keel at 16 wk was greater in the Avi pullets compared to the Conv pullets (P < 0.01). Wing and breast muscle weights of the Avi pullets were greater than the Conv pullets (P < 0.001), but leg muscle weights were greater in the Conv pullets (P = 0.026). Avi pullets had greater total bone density, total cross-sectional area, cortical cross-sectional area, total bone mineral content, and cortical bone mineral content than Conv pullets for the radius, humerus, and tibia (P < 0.001). Avi pullets had greater BBS compared to the Conv pullets for the radius, humerus, and tibia (P < 0.01). Increased opportunities for exercise offered by the aviary rearing system increased muscle and bone growth characteristics in pullets at 16 wk of age.

Wild birds that forage around livestock facilities have been implicated as vectors of antimicrobial resistant organisms. Although antimicrobial resistant bacteria have been isolated from European starlings (Sturnus vulgaris), their role in the dissemination of antimicrobial resistant elements in livestock facilities needs further investigation. To determine whether on-farm starling density and other factors were associated with the presence of cefotaxime and ciprofloxacin resistant E. coli among dairy cows in Ohio, bovine fecal pats from 150 farms were tested for the presence of cefotaxime and ciprofloxacin resistant E. coli. Each farm was visited twice (during the summer and fall of 2007-2009). Multi-level logistic regression models with a random intercept to account for fecal pats collected within a specific visit to a farm were used to assess the associations. The percentage of samples with cefotaxime and ciprofloxacin resistant E. coli was 13.4% and 13.6%, respectively. The percentage of farms having at least one sample testing positive for cefotaxime and ciprofloxacin resistant E. coli was 56.7% and 48.7%, respectively. The odds of detecting cefotaxime and ciprofloxacin resistant E. coli in the samples was significantly higher in 2007 compared to 2008 and 2009, in fall compared to summer, and from farms closer than 60km to starling night roost sites compared to the farms further than 60km. The presence of starlings during the day had a negative association with the likelihood of detecting cefotaxime resistant E. coli. Presence of calves also had a negative association with the likelihood of detecting both cefotaxime and ciprofloxacin resistant E. coli. European starlings might play a role in the dissemination of antimicrobial resistant agents in livestock facilities related to their daily population movements rather than the specific density of birds on farm during the day.

Here, we address the issue of experimental design for animal and crop disease transmission experiments, where the goal is to identify some characteristic of the underlying infectious disease system via a mechanistic disease transmission model. Design for such non-linear models is complicated by the fact that the optimal design depends upon the parameters of the model, so the problem is set in simulation-based, Bayesian framework using informative priors. This involves simulating the experiment over a given design repeatedly using parameter values drawn from the prior, calculating a Monte Carlo estimate of the utility function from those simulations for the given design, and then repeating this over the design space in order to find an optimal design or set of designs. Here we consider two agricultural scenarios. The first involves an experiment to characterize the effectiveness of a vaccine-based treatment on an animal disease in an in-barn setting. The design question of interest is on which days to make observations if we are limited to being able to observe the disease status of all animals on only two days. The second envisages a trial being carried out to estimate the spatio-temporal transmission dynamics of a crop disease. The design question considered here is how far apart to space the plants from each other to best capture those dynamics. In the in-barn animal experiment, we see that for the prior scenarios considered, observations taken very close to the beginning of the experiment tend to lead to designs with the highest values of our chosen utility functions. In the crop trial, we see that over the prior scenarios considered, spacing between plants is important for experimental performance, with plants being placed too close together being particularly deleterious to that performance.

Non-commercial poultry flocks (referred to as “small flocks”) have become increasingly popular in Canada. Despite this popularity, little is known about the main causes of morbidity and mortality (health status) in these flocks. We assessed the baseline prevalence of infectious and non-infectious diseases among Ontario’s small poultry flocks by conducting a prospective surveillance study over a 2-y period. With the owner’s consent, for each bird ( n = 245) submitted to the Animal Health Laboratory, we performed a postmortem examination, including ancillary tests to reach a diagnosis. Infectious diseases were the most common primary cause of clinical signs or death (62%), with multifactorial respiratory diseases (21%) and Marek’s disease (11%) being most frequent. Multifactorial respiratory diseases were commonly caused by coinfection with bacteria (e.g., Mycoplasma gallisepticum and M. synoviae, Escherichia coli, Avibacterium spp.) and viruses, such as infectious bronchitis and infectious laryngotracheitis viruses. No federally reportable diseases were diagnosed. The health status of small flocks in Ontario has not been reported previously, to our knowledge, and the data presented herein will produce helpful baseline information for the development of technology transfer material directed to owners and veterinarians, which will ultimately aid in the control of diseases among these flocks.

Antimicrobial resistance in Campylobacter, common in poultry, is a global public health issue. The emergence and spread of antimicrobial resistant Campylobacter has been linked to the use of antimicrobials in food animals. Small poultry flocks are becoming increasingly popular not only as a source of food but also as pets, yet not all small flock owners are aware of proper antimicrobial use practices and safe food handling protocols. This trend could contribute to antimicrobial resistance. In order to determine the prevalence of antimicrobial resistance in Campylobacter in small poultry flocks, we analyzed data from birds that had been submitted to a diagnostic laboratory in Ontario between October 2015 and September 2017. A pooled cecal sample was obtained from each submission and cultured for Campylobacter jejuni and Campylobacter coli. Three isolates were recovered from each positive sample and tested for susceptibility to nine antimicrobials using a broth microdilution method. Overall, 176 isolates were recovered (141 chicken, 21 turkey, 6 duck, and 8 game bird). A high frequency of resistance to tetracycline was observed in the C. jejuni isolates from chickens (77%) and turkeys (100%), and in the C. coli isolates from turkeys (50%) and game birds (40%). Campylobacter jejuni isolates had higher odds of resistance to tetracycline (OR = 3.54, P ≤ 0.01) compared to C. coli isolates. Overall, there was a low frequency of resistance to quinolones and a very low frequency of resistance to macrolides. Multidrug resistance was uncommon. The high prevalence of tetracycline resistance emphasizes the importance of prudent antimicrobial use in small flocks. Although low, the presence of resistance to macrolides and quinolones, which are used to treat campylobacteriosis in humans, highlights the need for proper food safety and infection control practices by small flock owners to prevent exposure to antimicrobial resistant Campylobacter.

Summary European starlings (Sturnus vulgaris) have been implicated in the dispersal of zoonotic enteric pathogens. However, their role in disseminating antimicrobial-resistant organisms through their home range has not been clearly established. The aim of this study was to determine whether starling night roosts served as foci for spreading organisms with reduced susceptibility to antimicrobials among dairy cattle farms. Bovine faecal pats were collected from 150 dairy farms in Ohio. Each farm was visited twice (in summer and fall) between 2007 and 2009. A total of 1490 samples (10 samples/farm over two visits) were tested for Escherichia coli with reduced susceptibility to cefotaxime and ciprofloxacin. Using a spatial scan statistic, focal scans were conducted to determine whether clusters of farms with a high prevalence of organisms with reduced susceptibility to cefotaxime and ciprofloxacin surrounded starling night roosts. Faecal pats 13.42% and 13.56% of samples carried Escherichia coli with reduced susceptibility to cefotaxime and ciprofloxacin, respectively. Statistically significant (P

Broiler breeders are feed-restricted during rearing to avoid the negative consequences of obesity during lay due to their genetic potential for fast growth rate. Feed restriction leads to chronic hunger, frustration and lack of satiety as indicated by hyperactivity, restlessness and oral-redirected behaviours that can become abnormal repetitive behaviours (ARBs). The objective of this study was to examine the effect of a rationed alternative diet and non-daily feeding schedules on the behaviour of broiler breeder pullets under simulated commercial conditions. At 3 weeks of age, 1680 Ross 308 pullets were allocated into 24 pens where they were fed with one of four isocaloric treatments until 22 weeks: 1) daily control diet; 2) daily alternative diet; 3) 4/3 control diet (four on-feed days with three non-consecutive off-feed days per week); and 4) graduated control diet (the feeding frequency varied with age). The alternative diet included a fixed inclusion rate of 40 % soybean hulls and an increasing concentration of 1–5 % calcium propionate. Ten focal pullets per pen (five on on-feed days, five on off-feed days) were continuously observed for 10 min at 7, 10, 14, and 18 weeks of age, starting 30 min after feed delivery. Data were analyzed using mixed linear regression models, with pen nested in the model and age or time of day as a repeated measure. Throughout rearing, pullets on the daily control diet were more active than pullets on the other three treatments (P

Avian pathogenic Escherichia coli (APEC) is the causative agent of colibacillosis in poultry, an economically important disease worldwide. In Ontario, Canada, early and late systemic bacterial infections due to APEC were the most commonly reported diseases in broiler chickens. In 2016, Ontario poultry veterinarians submitted samples from 331 cases of broiler and broiler breeder chickens with a high suspicion of colibacillosis to the Animal Health Laboratory (Guelph, Ontario, Canada) for bacterial culture. Escherichia coli isolates from those samples were tested with multiplex PCR to detect the presence of 13 virulence-associated genes. The most common genes identified were sitA (detected in 93% of isolates), iss (88%), iroN (85%), iutA (79%), ompT (77%), and etsB (67%). In 94% of isolates, at least three virulence-associated genes were detected. Antimicrobial susceptibility testing of isolates by using the disk diffusion method revealed high frequencies of resistance to tetracycline (57% of isolates), gentamicin (50%), spectinomycin (46%), and ampicillin (44%). Relatively fewer isolates were resistant to trimethoprim-sulfamethoxazole (18%), ceftiofur (15%), kanamycin (11%), and apramycin (3%). A high proportion (46%) of the isolates were multidrug resistant (≥3 antimicrobial classes). On the basis of multivariable, mixed effects logistic regression models, statistically significant associations ( P ≤ 0.05) were identified between the following: ampicillin resistance and the presence of kpsII (odds ratio [OR] = 1.88), tsh (OR = 0.46), and ireA (OR = 0.32); ceftiofur resistance and etsB (OR = 2.98) and kpsII (OR = 2.61); gentamicin resistance and ompT (OR = 3.89) and sitA (OR = 3.54); kanamycin resistance and papC (OR = 50.10); spectinomycin resistance and ireA (OR = 2.50) and iutA (OR = 3.15); trimethoprim-sulfamethoxazole resistance and ompT (OR = 0.14) and tsh (OR = 0.31); and tetracycline resistance and cvaC (OR = 2.12), eitA (OR = 2.15), and papC (OR = 8.27). On the basis of a multivariable, mixed effects Poisson regression model, the number of antimicrobials to which an isolate was resistant increased with the presence of eitA (risk ratio [RR] = 1.37), iroN (RR = 1.24), papC (RR = 1.34), and sitA (RR = 1.77) and decreased with the presence of tsh (RR = 0.79). On the basis of bivariable logistic regression models, age group and time of sample collection were not significantly associated with resistance to individual antimicrobials, the presence of multidrug resistance, or the presence of virulence-associated genes. Our results provide information on antimicrobial resistance and virulence gene patterns currently present on Ontario broiler chicken and broiler breeder farms that can be used as a benchmark from which to measure changes.

The objective of this study was to compare the flock-level prevalence of healed keel bone fractures and to benchmark other indicators of well-being in laying hens housed in conventional cages and single-tier floor housing systems at several points during the production period. Commercial farms in Ontario, Canada, that housed hens in cages (n=9) or floor barns (n=8) were included. Flocks were beak-trimmed brown hens of various strains. Each flock was visited at 20, 35, 50, and 65 wk of age. At each visit, 50 hens were weighed, palpated for healed keel fractures, and feather scored over 4 areas of the body. Data were collected from the farm records on cumulative mortality. Keel fracture prevalence was higher in floor-housed flocks compared to cage-housed flocks (48.3±0.04% vs. 24.8±0.03%; P0.001). The majority of keel fractures occurred by 50 wk. Cumulative mortality tended to be higher in floor-housed flocks compared to cage-housed flocks (2.13±0.42% vs. 1.29±0.19%; P=0.078). Mean BW was lower (1,827±28.8 g vs. 1,888±26.8 g; P=0.02) yet more uniform (CV of BW 9.43±0.40% vs. 10.10±0.32%; P0.001) in floor-housed flocks compared to cage-housed flocks. Feather condition was not affected by housing system type (P=0.618), although it declined with age (P0.001). Individual hen factors assessed using Pearson partial correlations indicated that hens with fractures were heavier at 65 wk in both housing types (P0.05) and that heavier hens housed on the floor had better feather scores (P0.001) from 35 wk onward. Floor-housed hens with fractures had lower feather scores at 35 wk (P0.05) but not at 50 or 65 wk. Housing hens in single-tier floor systems increased the flock-level prevalence of keel fractures and resulted in a lower, yet more uniform, BW compared to hens in conventional cages under commercial conditions in Ontario. Benchmarking welfare indicators from alternative housing systems for laying hens is important to ensure that progress is made in improving their well-being.

Avian reovirus (ARV) is an economically significant pathogen of broiler chickens. Our objective was to determine the prevalence, geographical distribution, and seasonal variation of ARV infection among commercial broiler flocks in Ontario, Canada during grow-out. A cross-sectional study of 231 randomly selected flocks was conducted from July 2010 to January 2012. Fifteen blood samples, 15 whole intestines, and 15 cloacal swabs per flock were collected at slaughter; ELISA and PCR were used to determine a flock’s ARV exposure status. Avian reovirus prevalence was 91% (95% CI: 87 to 94). District alone did not significantly explain the overall variation in the prevalence of ARV (univariable logistic regression; P = 0.073), although geographical differences were identified. The odds of ARV presence were significantly lower in the summer/autumn compared to the winter/spring (univariable exact logistic regression; P < 0.001). There was no association between flock mortality and flock ELISA mean titer or PCR status.

Samples from 231 randomly selected commercial broiler chicken flocks in Ontario were tested at slaughter for exposure to chicken anemia virus (CAV), fowl adenovirus (FAdV), and infectious bursal disease virus (IBDV). Fifteen blood samples per flock were collected and analyzed for the presence of antibodies against CAV, FAdV, and IBDV by ELISA or agar gel immunodiffusion test. Fifteen cecal tonsils and cloacal swabs per flock were analyzed for the presence of CAV, FAdV, and IBDV by PCR. The prevalence of exposure to avian adeno-associated virus (AAAV) was estimated by a PCR test on a subset of FAdV-PCR-positive samples from 178 flocks. Genotypes of FAdV and IBDV were identified on a subset of isolates (n = 353 and 45, respectively). The flock-level period prevalence of exposure to AAAV, CAV, FAdV, and IBDV during grow-out were 88.76% (95% CI: 84.08-93.45%), 77.06% (95% CI: 71.59-82.52%), 96.54% (95% CI: 94.16-98.91%), and 48.92% (95% CI: 42.42-55.41%), respectively. Results of a multivariable logistic regression model showed a significant association of exposure to FAdV with exposure to AAAV (OR = 18.57, 95% CI: 3.67-93.86, P = 0.004) but not with exposure to CAV (P = 0.7752) or exposure to IBDV (P = 0.2274). Pathogenic FAdV genotypes (FAdV-02, FAdV-08, and FAdV-11) constituted 39.38% of the isolates. The most-common IBDV genotypes identified were IBDV NC171 (60%) and IBDV 05SA8 (28.89%). This is the first large-scale study to estimate the baseline flock prevalence of exposure to AAAV, CAV, FAdV, and IBDV in commercial broiler flocks in Canada. Potentially pathogenic genotypes of FAdV and IBDV that can guide vaccine development and disease control efforts in Ontario were identified.

Avian intestinal spirochaetosis (AIS) is primarily a disease of layer and broiler breeder chickens exhibited by delayed and/or reduced egg production, increased mortality, weight loss, and chronic ...

Brachyspira species are frequent colonizers of the gastrointestinal tract in a variety of domestic animals, including birds. In chickens, Brachyspira species are associated with a clinical condition known as avian intestinal spirochetosis (AIS), a disease characterized by chronic diarrhoea, weight loss, low egg production, and faecal-stained eggs. The purpose of this study was to identify risk factors associated with the presence of Brachyspira species in Ontario layer chicken flocks. Pooled faecal samples were collected from 89 flocks from 58 farms between August 2010 and February 2011; 52 flocks were classified as dirty flocks (history of downgrades for dirty eggs) and 37 were classified as clean flocks (no history of downgrades for dirty eggs). A questionnaire related to management, biosecurity practices, and antimicrobial use was administered prior to sample collection. Using real-time polymerase chain reaction; 63.5% of the dirty flocks and 24.3% of the clean flocks were positive for Brachyspira species. A logistic regression model with a random effect for farm showed that the odds of Brachyspira species for flocks ≥ 60 weeks of age were higher than for flocks ≤ 34 weeks (OR = 9.3; P = 0.014). The odds of Brachyspira species in flocks housed in A-frame cages with manure curtains (OR = 20.0; P = 0.002) and flocks from multi-age farms (OR = 8.5; P = 0.001) were higher than for flocks in cage-stacked houses and from single-age farms, respectively. The odds of Brachyspira species for flocks housed in barns ≥ 30 years old was lower than for flocks housed in barns ≤ 14 years old (OR = 0.1; P = 0.002). The calculated intra-class correlation coefficient was 5.6 × 10−14; the notably low proportion of variation among farms after the fixed effects were included in the model suggests that the farm-level variable (multi-age farm) included in the final model accounted for most of the farm-to-farm variation in Brachyspira presence. Therefore, it is recommended that strict biosecurity, and between-flock decontamination efforts to reduce the infection pressure, be followed on farms with multiple flocks of different ages to avoid transmission of the bacteria between flocks.

Many birds are able to modify migratory strategies when selection favours an adjustment. Climate change is provoking a range of responses from avian migrants and affecting their relationship with o...

Successful prevention, recognition, and treatment of pain are integral to ensuring veterinary patient welfare. A canine and feline welfare assessment tool, incorporating verbal interviews with veterinarians using open-ended questions, was developed to assess pain management practices that safeguard and improve patient welfare. The tool was evaluated in 30 companion- and mixed-animal veterinary clinics in Ontario in order to assess its reliability, feasibility, and validity, while also benchmarking current practices. Responses were analyzed according to a scoring scheme developed based on published literature and expert opinion. Based on weighted kappa statistics, interview scoring had substantial inter-observer (Kw = 0.83, 0.73) and near-perfect intra-observer (Kw = 0.92) agreement, which suggests that the tool reliably collects information about pain management practices. Interviews were completed at all recruited clinics, which indicates high feasibility for the methods. Validity could not be assessed, as participants were reluctant to share information about analgesic administration from their clinical records. Descriptive results indicated areas for which many veterinarians are acting in accordance with best practices for pain management, such as pre-emptive and post-surgical analgesia for ovariohysterectomy patients, and post-surgical care instructions. Areas that offer opportunity for enhancement were also highlighted, e.g., training veterinary staff to recognize signs of pain and duration of analgesia in ovariohysterectomy patients after discharge. Overall, based on this limited sample, most veterinarians appear to be effectively managing their patients’ pain, although areas with opportunity for enhancement were also identified. Further research is needed to assess trends in a broader sample of participants.

High flock-level prevalence of keel-bone fractures and deviations in laying hens are commonly reported across various housing systems; however, few longitudinal studies exist, especially for furnished and conventional cage systems. Load-bearing exercise improves bone strength and mineral composition in laying hens and has the potential to reduce keel-bone damage, especially if exercise is allowed during critical periods of bone growth throughout the pullet rearing phase. The objective of this study was to determine the prevalence of keel-bone damage in laying hens housed in furnished and conventional cages, and assess whether opportunities for exercise during the pullet rearing phase influenced the prevalence of keel-bone damage throughout the laying period. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets/flock were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S) or 60-bird furnished cages (FC-L) for adult housing. Keel-bone status was determined by palpation at 30, 50, and 70 wk of age. Age (P

Background In Ontario and Canada, the incidence of human Salmonella enterica serotype Enteritidis (S. Enteritidis) infections have increased steadily during the last decade. Our study evaluated the spatial and temporal epidemiology of the major phage types (PTs) of S. Enteritidis infections to aid public health practitioners design effective prevention and control programs. Methods Data on S. Enteritidis infections between January 1, 2008 and December 31, 2009 were obtained from Ontario’s disease surveillance system. Salmonella Enteritidis infections with major phage types were classified by their annual health region-level incidence rates (IRs), monthly IRs, clinical symptoms, and exposure settings. A scan statistic was employed to detect retrospective phage type-specific spatial, temporal, and space-time clusters of S. Enteritidis infections. Space-time cluster cases’ exposure settings were evaluated to identify common exposures. Results 1,336 cases were available for analysis. The six most frequently reported S. Enteritidis PTs were 8 (n = 398), 13a (n = 218), 13 (n = 198), 1 (n = 132), 5b (n = 83), and 4 (n = 76). Reported rates of S. Enteritidis infections with major phage types varied by health region and month. International travel and unknown exposure settings were the most frequently reported settings for PT 5b, 4, and 1 cases, whereas unknown exposure setting, private home, food premise, and international travel were the most frequently reported settings for PT 8, 13, and 13a cases. Diarrhea, abdominal pain, and fever were the most commonly reported clinical symptoms. A number of phage type-specific spatial, temporal, and space-time clusters were identified. Space-time clusters of PTs 1, 4, and 5b occurred mainly during the winter and spring months in the North West, North East, Eastern, Central East, and Central West regions. Space-time clusters of PTs 13 and 13a occurred at different times of the year in the Toronto region. Space-time clusters of PT 8 occurred at different times of the year in the North West and South West regions. Conclusions Phage type-specific differences in exposure settings, and spatial-temporal clustering of S. Enteritidis infections were demonstrated that might guide public health surveillance of disease outbreaks. Our study methodology could be applied to other foodborne disease surveillance data to detect retrospective high disease rate clusters, which could aid public health authorities in developing effective prevention and control programs. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-2592-6) contains supplementary material, which is available to authorized users.

A systematic review was conducted to evaluate the change in prevalence of Campylobacter on chicken carcasses during processing. A structured literature search of 8 electronic databases using the key words for "Campylobacter," "chicken," and "processing" identified 1,734 unique citations. Abstracts were screened for relevance by 2 independent reviewers. Thirty-two studies described prevalence at more than one stage during processing and were included in this review. Of the studies that described the prevalence of Campylobacter on carcasses before and after specific stages of processing, the chilling stage had the greatest number of studies (9), followed by washing (6), defeathering (4), scalding (2), and evisceration (1). Studies that sampled before and after scalding or chilling, or both, showed that the prevalence of Campylobacter generally decreased immediately after the stage (scalding: 20.0 to 40.0% decrease; chilling: 100.0% decrease to 26.6% increase). The prevalence of Campylobacter increased after defeathering (10.0 to 72.0%) and evisceration (15.0%). The prevalence after washing was inconsistent among studies (23.0% decrease to 13.3% increase). Eleven studies reported the concentration of Campylobacter, as well as, or instead of, the prevalence. Studies that sampled before and after specific stages of processing showed that the concentration of Campylobacter decreased after scalding (minimum decrease of 1.3 cfu/g, maximum decrease of 2.9 cfu/mL), evisceration (0.3 cfu/g), washing (minimum 0.3 cfu/mL, maximum 1.1 cfu/mL), and chilling (minimum 0.2 cfu/g, maximum 1.7 cfu/carcass) and increased after defeathering (minimum 0.4 cfu/g, maximum 2.9 cfu/mL). Available evidence is sparse and suggests more data are needed to understand the magnitude and mechanism by which the prevalence and concentration of Campylobacter changes during processing. This understanding should help researchers and program developers identify the most likely points in processing to implement effective control efforts. For example, if contamination will occur during defeathering and likely during evisceration, critical control points postevisceration are likely to have a greater effect on the end product going to the consumer.

Background Salmonella enterica serotype Enteritidis (S. Enteritidis) remains a major foodborne pathogen in North America yet studies examining the spatial epidemiology of salmonellosis in urban environments are lacking. Our ecological study combined a number of spatial statistical methods with a geographic information system to assess area-level heterogeneity of S. Enteritidis infection rates in the city of Toronto. Methods Data on S. Enteritidis infections between January 1, 2007 and December 31, 2009 were obtained from Ontario’s surveillance system, and were grouped and analyzed at the forward sortation area (FSA)-level (an area signified by the first three characters of the postal code). Incidence rates were directly standardized using the FSA-level age- and sex-based standard population. A spatial empirical Bayes method was used to smooth the standardized incidence rates (SIRs). Global clustering of FSAs with high or low non-smoothed SIRs was evaluated using the Getis-Ord G method. Local clustering of FSAs with high, low, or dissimilar non-smoothed SIRs was assessed using the Getis-Ord Gi* and the Local Moran’s I methods. Results Spatial heterogeneity of S. Enteritidis infection rates was detected across the city of Toronto. The non-smoothed FSA-level SIRs ranged from 0 to 16.9 infections per 100,000 person-years (mean = 6.6), whereas the smoothed SIRs ranged from 2.9 to 11.1 (mean = 6.3). The global Getis-Ord G method showed significant (p ≤ 0.05) maximum spatial clustering of FSAs with high SIRs at 3.3 km. The local Getis-Ord Gi* method identified eight FSAs with significantly high SIRs and one FSA with a significantly low SIR. The Local Moran’s I method detected five FSAs with significantly high-high SIRs, one FSA with a significantly low-low SIR, and four significant outlier FSAs (one high-low, and three low-high). Conclusions Salmonella Enteritidis infection rates clustered globally at a small distance band, suggesting clustering of high SIRs in small distinct areas. This finding was supported by the local cluster analyses, where distinct FSAs with high SIRs, mainly in downtown Toronto, were detected. These areas should be evaluated by future studies to identify risk factors of disease in order to implement targeted prevention and control programs. We demonstrated the usefulness of combining several spatial statistical techniques with a geographic information system to detect geographical areas of interest for further study, and to evaluate spatial processes that influenced S. Enteritidis infection rates. Our study methodology could be applied to other foodborne disease surveillance data. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1106-6) contains supplementary material, which is available to authorized users.

The objective of this study was to assess beak shape variation in domestic turkeys (Meleagris gallopavo) and determine the effects of age, sex, and beak size on beak shape variation using geometric morphometrics. Dorsal and right lateral images were taken of 2442 turkeys at 6 and 18.5 weeks of age. Landmarks were digitized in tpsDig in three analyses of the dorsal upper mandible, lateral upper mandible, and lateral lower mandible shape of each turkey at both ages. The coordinate data were then subjected to a principal components analysis (PCA), multivariate regression, and a canonical variates analysis (CVA) with a Procrustes ANOVA in MorphoJ. For the dorsal images, three principal components (PCs) showed beak shape variation ranged from long, narrow, and pointed to short, wide, and blunt upper mandibles at both ages (6 weeks: 95.36%, 18.5 weeks: 92.21%). Three PCs showed the lateral upper mandible shape variation ranged from long, wide beaks with long, curved beak tips to short, narrow beaks with short, pointed beak tips at both ages (6 weeks: 94.91%, 18.5 weeks: 94.33%). Three PCs also explained 97.80% (6 weeks) and 97.11% (18.5 weeks) of the lateral lower mandible shape variation ranging from wide and round to narrow and thin lower mandibles with superior/inferior beak tip shifts. Beak size accounted for varying proportions of the beak shape variation (0.96–54.76%; P < 0.0001) in the three analyses of each age group. For all the analyses, the CVA showed sexual dimorphism in beak shape (P < 0.0001) with female upper mandibles appearing wider and blunter dorsally with long, curved beak tips laterally. Whereas male turkey upper mandibles had a narrow, pointed dorsal appearance and short, pointed beak tips laterally. Future applications of beak shape variability could have a genetic and welfare value by incorporating beak shape variation to select for specific turkey beak phenotypes as an alternative to beak treatment.

Infectious bronchitis virus (IBV) was detected in 185 samples originating from chicken flocks of various commodity groups in Canada. Flocks with clinical signs such as respiratory challenge, sudden death, egg production problems, or nephropathogenic conditions, and randomly selected flocks sampled at slaughter as part of an Ontario broiler surveillance project, were included. Most samples were from Ontario and Quebec; however, a small number from British Columbia, Nova Scotia, and Newfoundland and Labrador were also analysed. The nucleotide sequence of the spike (S) protein gene was compared with sequences available in GenBank. Based on their S gene sequence similarities, Canadian IBVs could be divided into nine genotypes belonging to four groups: Canadian variant virus, strain Qu_mv; the classic, vaccine-like viruses, Connecticut and Massachusetts; US variant-like virus strains, California 1734/04, California 99, CU_82792, Pennsylvania 1220/98 and Pennsylvania Wolg/98; and non-Canadian, non-US virus, strain 4/91. Based on the field situation, the effectiveness of current vaccination practices mostly based on Massachusetts and Connecticut-type vaccines appeared generally satisfactory for minimizing the damage due to infection with Canadian variant and US variant-like viruses. However, the recent outbreaks of severe respiratory disease and production problems in Ontario chicken flocks related to the incursion of IBV strain 4/91 were not prevented by standard vaccination protocols. It appears that IBV strain 4/91 has now become endemic in Ontario and the need for 4/91-type vaccines must be evaluated.

The objectives of this study were to understand the temporal pattern of contamination of cattle feed by starling excrement on dairy farms and to evaluate the temporal pattern in recovering Escherichia coli O157:H7 or Salmonella in relation to the absolute mass of excrement recovered. A longitudinal study was conducted on 15 dairy farms in Ohio from July 2007 to October 2008. One open-topped tray filled with bird feed was placed near a cattle feeding site; bird excrement from the tray was weighed monthly for 12 consecutive months. Linear regression models with a random intercept for farm were computed to examine the association between the absolute weight of excrement recovered each month or the farm-specific standard score for weight of excrement, and month or season. Exact logistic regression was used to determine whether an association between recovering E. coli O157:H7 or Salmonella was present and the amount of excrement recovered and season. A spatial scan statistic was used to test for evidence of space–time clustering of excrement, based on the standard score for the weight of the excrement, among our study farms. A total of 5 of 179 excrement samples (2.79%) were positive for E. coli O157:H7 and 2 (1.12%) were positive for Salmonella . A significantly higher level of contamination with excrement was observed during the winter. The odds of recovering a pathogen increased with the amount of excrement recovered and decreased if the excrement was collected in the winter. A spatio-temporal cluster of contamination with excrement was detected. These findings provide basic information for future quantitative microbial risk assessments concerning the role of starlings in spreading enteric pathogens on dairy farms.

Poultry barns provide an ideal breeding environment for Musca domestica L. (Diptera: Muscidae) owing to the controlled temperatures and litter (manure plus bedding material) accumulation. Management techniques that render the litter less suitable for immature stage development, such as the addition of naturally occurring insecticidal substances, could reduce fly infestations. The effectiveness of acetic, boric, and citric acids; diatomaceous earth; and hydrated lime at restricting female landing and growth of house flies in duck litter was evaluated. Litter treated with 1.9% and 4.7% by weight of acetic or boric acid had significantly lower adult emergence rates compared with the same concentrations of citric acid, diatomaceous earth, hydrated lime, or the untreated control litter. The pH of duck litter treated with acetic or citric acid was significantly reduced and remained significantly lower than the control litter (pH 8.7) for 10 d. Significantly more house flies landed on a house fly-rearing substrate (wheat bran, powdered milk, bloodmeal, water, and yeast) than litter treated with any of the other test substances or the control. The LC50 for boric acid was estimated to be 0.01% by weight, which was lower than that of acetic acid (1.42%). Similarly, the LC90 of boric acid was estimated to be 0.12%, which was lower than that of acetic acid (10.03%). Acetic acid and boric acid have the potential to be incorporated into litter as a pest management tactic to reduce house fly populations in duck production facilities.

A temporal study was carried out to determine Salmonella prevalence, trends, major serovars, and their clusters from environmental samples, in poultry breeder flocks in Ontario between January 1998 and December 2008. Surveillance data were obtained from the Ontario Hatchery and Supply Flock Policy. Logistic regression with a random effect for flock was used to identify factors [poultry type, year (trend) and season] associated with the prevalence of Salmonella. A cluster detection test was used to identify clusters of common serovars. The period prevalence of Salmonella was 47.4% in broiler-breeder, 25.7% in layer-breeder, and 19.6% in turkey-breeder flocks. The overall trend in the prevalence of Salmonella was decreasing for all breeder types, due primarily to decreasing trends of Salmonella Heidelberg. The seasonal effects varied by year with the highest probability of Salmonella occurring in different seasons. The 4 most common serovars identified were Salmonella Heidelberg, Kentucky, Hadar, and Typhimurium in broiler-breeders; Salmonella Heidelberg, Brandenburg, Thompson, and Typhimurium in layer-breeders; and Salmonella Heidelberg, Saintpaul, Brandenburg, and Muenster in turkey-breeders. Salmonella Enteritidis was infrequently isolated in all poultry breeder types. Temporal clusters of different serovars were identified in all poultry breeder types. Clusters of Salmonella Heidelberg, Typhimurium, and Hadar from environmental samples from breeder flocks were detected during a similar period to clusters from hatchery fluff samples from the same population. Therefore, interventions at the breeder flock-level might help to reduce transmission of Salmonella from breeder flocks to hatcheries and possibly, to lower levels of the poultry production chain.Une étude temporelle a été menée afin de déterminer la prévalence de

Acute gastrointestinal illness is an important public-health issue worldwide. Burden-of-illness studies have not previously been conducted in Cuba. The objective of the study was to determine the magnitude, distribution, and burden of self-reported acute gastrointestinal illness in Cuba. A retrospective, cross-sectional survey was conducted in three sentinel sites during June-July 2005 (rainy season) and during November 2005–January 2006 (dry season). Households were randomly selected from a list maintained by the medical offices in each site. One individual per household was selected to complete a questionnaire in a face-to-face interview. The case definition was three or more bouts of loose stools in a 24-hour period within the last 30 days. In total, 97.3% of 6,576 interviews were completed. The overall prevalence of acute gastrointestinal illness was 10.6%. The risk of acute gastrointestinal illness was higher during the rainy season (odds ratio [OR]=3.85, 95% confidence interval [CI] 3.18-4.66) in children (OR=3.12, 95% CI 2.24-4.36) and teens (OR=2.27, 95% CI 1.51-3.41) compared to people aged 25-54 years, in males (OR=1.24, 95% CI 1.04-1.47), and in the municipality of Santiago de Cuba (OR=1.33, 95% CI 1.11-1.61). Of 680 cases, 17.1-38.1% visited a physician, depending on sentinel site. Of the cases who visited a physician, 33.3-53.9% were requested to submit a stool sample, and of those, 72.7-100.0% complied. Of the cases who sought medical care, 16.7- 61.5% and 0-31.6% were treated with antidiarrhoeals and antibiotics respectively. Acute gastrointestinal illness represented a substantial burden of health compared to developed countries. Targeting the identified risk factors when allocating resources for education, food safety, and infrastructure might lower the morbidity associated with acute gastrointestinal illness.

Background The concurrent rise in consumption of fresh chicken meat and human campylobacteriosis in the late 1990's in Iceland led to a longitudinal study of the poultry industry to identify the means to decrease the frequency of broiler flock colonization with Campylobacter. Because horizontal transmission from the environment is thought to be the most likely source of Campylobacter to broilers, we aimed to identify broiler house characteristics and management practices associated with flock colonization. Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for Campylobacter. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Logistic regression models with a farm random effect were used to analyse the association between flock Campylobacter status and house-level risk factors. A two-stage process was carried out. Variables were initially screened within major subsets: ventilation; roof and floor drainage; building quality, materials and repair; house structure; pest proofing; biosecurity; sanitation; and house size. Variables with p ≤ 0.15 were then offered to a comprehensive model. Multivariable analyses were used in both the screening stage (i.e. within each subset) and in the comprehensive model. Results 217 out of 792 flocks (27.4%) tested positive. Four significant risk factors were identified. Campylobacter colonization was predicted to increase when the flock was raised in a house with vertical (OR = 2.7), or vertical and horizontal (OR = 3.2) ventilation shafts, when the producer's boots were cleaned and disinfected prior to entering the broiler house (OR = 2.2), and when the house was cleaned with geothermal water (OR = 3.3). Conclusion The increased risk associated with vertical ventilation shafts might be related to the height of the vents and the potential for vectors such as flies to gain access to the house, or, increased difficulty in accessing the vents for proper cleaning and disinfection. For newly constructed houses, horizontal ventilation systems could be considered. Boot dipping procedures should be examined on farms experiencing a high prevalence of Campylobacter. Although it remains unclear how geothermal water increases risk, further research is warranted to determine if it is a surrogate for environmental pressures or the microclimate of the farm and surrounding region.

Background Following increased rates of human campylobacteriosis in the late 1990's, and their apparent association with increased consumption of fresh chicken meat, a longitudinal study was conducted in Iceland to identify the means to decrease the frequency of broiler flock colonization with Campylobacter. Our objective in this study was to identify risk factors for flock colonization acting at the broiler farm level. Methods Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for Campylobacter. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Flock results were collapsed to the farm level, such that the number of positive flocks and the total number of flocks raised were summed for each farm. Logistic regression models were fitted to the data using automated and manual selection methods. Variables of interest included manure management, water source and treatment, other poultry/livestock on farm, and farm size and management. Results The 792 flocks raised during the summer seasons originated from 83 houses on 33 farms, and of these, 217 (27.4%) tested positive. The median number of flocks per farm was 14, and the median number of positive flocks per farm was three. Three farms did not have any positive flocks. In general, factors associated with an increased risk of Campylobacter were increasing median flock size on the farm (p ≤ 0.001), spreading manure on the farm (p = 0.004 to 0.035), and increasing the number of broiler houses on the farm (p = 0.008 to 0.038). Protective factors included the use of official (municipal) (p = 0.004 to 0.051) or official treated (p = 0.006 to 0.032) water compared to the use of non-official untreated water, storing manure on the farm (p = 0.025 to 0.029), and the presence of other domestic livestock on the farm (p = 0.004 to 0.028). Conclusion Limiting the average flock size, and limiting the number of houses built on new farms, are interventions that require investigation. Water may play a role in the transmission of Campylobacter, therefore the use of official water, and potentially, treating non-official water may reduce the risk of colonization. Manure management practices deserve further attention.

BACKGROUND: Temporal clusters of salmonellosis are believed to occur but have not been quantitatively explored, thus, our objectives were to describe trends, seasonal patterns, and clusters of salmonellosis in humans in Alberta by examining isolates reported through passive surveillance systems. METHODS: Cases of salmonellosis reported through Notifiable Disease Records between January 1990 and December 2001 were obtained from Alberta Health and Wellness. Least squares regression was used to characterize the distribution (long-term trends and seasonal patterns) of isolates. A cluster detection test was used to determine if and when isolates of specific serovars aggregated in time, over and above the background distribution. Comparisons were made to temporal patterns in Alberta livestock and to known outbreaks in humans. RESULTS: S. Typhimurium, Enteritidis, Hadar, Heidelberg, and Thompson were the five most common serovars of the 9,188 isolates reported. The annual number of isolates was relatively stable over time, with a distinct summertime seasonal pattern. Clusters were observed in 23 of 32 serovars examined. More clusters occurred in September and October than in other months, and in 1998 through 2001 than in the early to mid-1990s. Also, more clusters were of short duration than long. INTERPRETATION: Short-duration clusters likely indicate a point source of infection, while long-duration clusters may indicate exposure to a persistent common source or the occurrence of secondary infections. A sharp increasing trend and a large cluster of S. Heidelberg may have public health implications. Surveillance activities focussed on similarities between common serovars, trends, and temporal clusters in humans and animals, and studies on factors associated with autumn clusters may be useful in preventing outbreaks in humans.

Passive laboratory-based surveillance data from Alberta Agriculture Food and Rural Development were analyzed for common Salmonella serovars, prevalences, trends, and for the presence of temporal clusters. There were 1767 isolates between October 1990 and December 2001 comprising 63 different serovars, including 961 isolates from chickens, 418 from cattle, 108 from pigs, 102 from turkeys, and 178 from all other species combined. Salmonella Typhimurium, Heidelberg, Hadar, Kentucky, and Thompson were the 5 most frequently isolated serovars. Approximately 60% of the S. Typhimurium were isolated from cattle, whereas over 90% of the S. Heidelberg, Hadar, Kentucky, and Thompson were isolated from chickens. Salmonella Enteritidis was rarely isolated. There was an increasing trend in isolates from chickens, cattle, and pigs, and a decreasing trend in isolates from turkeys. Temporal clusters were observed in 11 of 15 serovars examined in chickens (S. Anatum, Heidelberg, Infantis, Kentucky, Mbandaka, Montevideo, Nienstedten, Oranienburg, Thompson, Typhimurium, and Typhimurium var. Copenhagen), 5 of 5 serovars in cattle (S. Dublin, Montevideo, Muenster, Typhimurium, and Typhimurium var. Copenhagen), and 1 of 3 serovars in pigs (S. Typhimurium). Short-duration clusters may imply point source infections, whereas long-duration clusters may indicate an increase in the prevalence of the serovar, farm-to-farm transmission, or a wide-spread common source. A higher concentration of clusters in the winter months may reflect greater confinement, reduced ventilation, stressors, or increased exposure to wildlife vectors that are sharing housing during the winter. Detection of large clusters of Salmonella may have public health implications in addition to animal health concerns.