Organic Flocks Research Articles

Development and evaluation of an animal health and welfare monitoring system for veterinary supervision of pullet farms.

Regular welfare monitoring throughout rearing of pullets may help to identify problems early and take counteractions timely, which helps in guaranteeing good welfare. The aims of our observational study were (i) to establish and test a welfare monitoring system that can be used during (short) routine veterinary and technical staff visits for pullet flocks, (ii) to use the monitoring system to investigate variability between flocks and (iii) to analyse factors that potentially affect pullets' body weight, uniformity in body weight and mortality. The developed monitoring system tries to minimise the time required while not losing important information. Age-specific recording sheets comprise animal-based indicators of welfare and relevant environmental factors (housing, management, care) to allow for identifying causes of problems and targeted action. Finally, the system was implemented in a cross-sectional study and data collected in 100 flocks (67 organic, 33 conventional) on 28 rearing farms in Austria. Linear mixed models were used to identify factors influencing body weight, uniformity and mortality, both including all flocks (A) and only organic flocks (O) and a linear regression model with all flocks to investigate associations within animal-based indicators. High variability was found between flocks in animal-based indicators. Body weight was higher when the pre-rearing period was shorter (p≤0.001, A&O), with higher intensities of light (p=0.012, O), with only one compared to more stockpersons (p≤0.007, A&O), with a higher number of flock visits per day (p≤0.018, A&O), and a lower avoidance distance (p=0.034, A). Body weight uniformity increased, with age and decreased with the duration of the light period (p=0.046, A), and, amongst others, was higher on organic farms (farming type; p=0.041). The latter may reflect a more uniform level of welfare due to a lower stocking density and lowered effects of social competition. Within organic flocks mortality was lower if pullets had access to a covered veranda (p=0.025) resulting in an overall lower stocking density inside the barn, while in the model including all farms mortality was higher in cases where a disease had been diagnosed. We conclude that our monitoring system can easily be implemented in regular veterinary and technical staff visits, but could also be used by the farmers'. Several easy-to-record animal-based indicators of animal welfare could be analysed more frequently to increase early detection of problems. Implementation of such a routine-based monitoring system with easy-to-assess animal-based parameters and input measures can contribute to better animal health and welfare in pullets.

Association with Different Housing and Welfare Parameters on Results of a Novel Object Test in Laying Hen Flocks on Farm.

The objective of this on-farm study was to determine if flocks showing feather damage and/or cannibalism would have a higher fear response to the novel object (NOT) and the association between different housing and welfare parameters on results of the NOT. Therefore, 16 flocks were observed during the laying period in Germany. In total, there were six barns, seven free-range, and three organic flocks. The plumage and integument condition of 50 birds of each flock were evaluated at 4 different times during the laying period (V1: 18th to 23rd week of life, V2: 26th to 35th week of life, V3: 49th to 57th week of life, V4: 61st to 73rd week of life). At the same observation times, the NOT was performed in the flocks (at four different locations per visit time). Based on the average number of hens gathered around the novel object (NO) within the period of two minutes, conclusions can be made about the fearfulness of the flock. The present study shows that the more fearful a flock was, the more frequent feather damage (p < 0.001) and cannibalism (p < 0.01) occurred. Age and flock size were associated with fearfulness. Fearfulness of hens increased with the increasing age of hens (p < 0.001) and with an increasing flock size (p < 0.001). Hens of white feather color appeared to be more fearful than brown hens (p < 0.001). Hens kept on barn farms showed significantly lower numbers of hens around the novel object (p < 0.001) than on free-range farms, which possibly indicates that having permanent access to outdoor space generally appears to be associated with the fearfulness of a flock.

Investigation of Spotty Liver Disease and Campylobacter hepaticus in Layer Flocks-A Field Study.

Campylobacter hepaticus (C. hepaticus) was recently discovered as the causative agent of Spotty Liver Disease (SLD). SLD affects laying hens and causes significant economic losses in egg production in several countries throughout the world. Field observations reveal that cases of SLD appear with a high risk of reoccurrence, specifically in free-range and organic brown-feathered layer lines. Possible factors contributing to the development of SLD still have to be elucidated. In this field study, one free range (Flock 1) and one organic flock (Flock 2) of brown laying hens kept on farms with a history of clinical SLD were monitored for C. hepaticus colonization, clinical signs, and egg production from 16 to 79 wk of age on the first farm and from 17 to 83 wk of age on the other. The flocks showed a significant drop in egg production at 32 to 39 or 56 wk of age, respectively, which was associated with macroscopically visible liver lesions typical for SLD. Interestingly, in both cases observed clinical disease was linked to a stressful event: heat stress for Flock 1 and respiratory symptoms for Flock 2. C. hepaticus was detected by PCR during the acute phase of the disease in Flock 1. At 50 wk after the initial clinical outbreak had waned, C. hepaticus was still able to be isolated by culture in this flock. This clearly demonstrates that C. hepaticus persists either in the birds or their environment. We speculate that this long persistence may favor chronic SLD in affected flocks and the reoccurrence of SLD in subsequent flocks. Clinically less severe SLD outbreaks may be observed after re-exposure of clinically recovered flocks.

Prevalence and molecular detection of Eimeria species in different types of poultry in Greece and associated risk factors.

Coccidiosis is one of the most notable diseases in chickens having a high economic impact on the poultry industry worldwide. The present study is the first attempt to epidemiologically investigate Eimeria spp. distribution and associated risk factors under different housing and production systems in three major regions in Greece. Faecal samples were obtained from 42 operations (broilers, floor housed, free range and organic layers, backyard farms). A questionnaire was obtained from included operations to acquire additional information regarding farm management, location, production rate and diseases history. Positivity level was 85.7%. All seven Eimeria species were identified, and the most prevalent ones were E. acervulina (79.3%) and E. tenella (65.5%). Single-species and mixed infections were detected in 20.7% and 79.3% of the flocks, respectively. Flock size, type of outdoor area, production system and presence of respiratory disease proved significant risk factors. Flock size up to 10,000 birds correlated strongly (p = 0.02) with higher E. tenella quantities. A very strong correlation (p < 0.001) was found between the presence of respiratory disease and the average OPG level in broiler farms. Organic flocks showed higher prevalence of E. tenella (p = 0.023), while presence of vegetation at the outdoor area correlated strongly with E. brunetti (p < 0.001). Molecular analysis and correlation results in this survey give strong indications although more studies are needed to further understand the involvement of different Eimeria species in various husbandry, production and management systems, to gain more knowledge about the sustainable control of coccidia in poultry.

Predictors for plumage damage and bloody lesions indicative of feather pecking in pullets reared in aviaries

Feather pecking remains a serious problem in poultry farming. This study aimed to identify risk factors for plumage damage as a proxy for feather pecking, and the predictive value of practical animal-based parameters. Data were collected in 100 flocks on 28 rearing farms in Austria, recording plumage damage in the 10th and bloody lesions in the 6th, 10th and 16th weeks of age; housing (e.g. pre-rearing on another farm, early rearing on the floor or aviary), management (e.g. provision of litter) and human-animal relationship (e.g. avoidance distance, farmers’ attitudes). Linear mixed models were calculated for plumage damage and generalized linear models for bloody lesions in the 10th week. Early floor-rearing of pullets with access to litter, instead of confinement in the aviary in the first weeks without access to litter, was associated with less plumage damage (P = 0.011). A shorter pre-rearing period on a different farm was associated with less plumage damage (P = 0.035). In organic flocks, bloody lesions tended to occur with a nearly three times lower probability with early floor-rearing than early aviary-rearing (P = 0.062) and when litter quantity in the 10th week was scored as high (P < 0.001). There were fewer down feathers on the ground when pullets had bloody lesions in the 10th week (P˂0.001). Farmers’ attitudes were associated with both plumage damage and bloody lesions; e.g. less plumage damage was observed when farmers ascribed more positive characteristics to pullets (P = 0.020). Avoidance of an unfamiliar human by the birds was associated with breed (P = 0.001) and was lower at higher stocking density (P = 0.005), but did not significantly predict plumage damage or bloody lesions. Farmers’ attitude analyses revealed that farmers who agreed more on the importance of regular contact had pullets with lower avoidance distance (P = 0.022). The results confirm the importance of access to litter from the first day of life onwards: early floor-rearing with access to litter can substantially reduce the risk of feather pecking compared to confinement in the aviary with chick paper only, in the first weeks of life. However, the pre-rearing period is best kept relatively short and appropriate litter later in life is important for the prevention of feather pecking. The absence of down feathers on the floor is easy to record on a regular basis for the early detection and potentially prevention of feather pecking. Farmers’ attitudes are important predictors for further variation in feather pecking between farms as well as in pullets’ fear of humans.

Impact of organic dairy cattle manure on environmental and egg microbiology of organic free-range laying hens

The popularity of free-range and organic poultry has increased in recent years due to consumer demands. A study was conducted to evaluate how the presence of organic dairy cattle manure could influence the environmental and egg microbiology of organic free-range laying flocks. A flock of brown egg layers was split and maintained in a rotational paddock grazing schedule of which was free of or exposed to organic dairy manure. Environmental and egg sampling occurred approximately every 8 wk between 20 and 44 wk of age for a presence of Listeria spp., Campylobacter spp., Salmonella spp., and enumeration of Enterobacteriaceae. There was no significant difference in the occurrence of Listeria spp., Campylobacter spp. and Salmonella spp. in environmental and egg samples between integrated and control grazing organic free-range flocks. A random sampling of Enterobacteriaceae colonies produced 211 viable isolates for biochemical identification. Seventeen genera, species, or serotypes were identified. There was a greater (P < 0.05) prevalence of total coliforms found on shell emulsion, egg contents, nest box straw, and forage samples from integrated organic free-range compared to control organic free-range flocks. Seasons of the year impacted microbial levels recovered from environmental and egg samples, with which summer having the highest level of all populations monitored. Additional studies are needed to fully understand the effect of mixed production rotational grazing on the prevalence of pathogens and Enterobacteriaceae on organic nest-run eggs and the grazing environment.

Feedborne Salmonella enterica Serovar Jerusalem Outbreak in Different Organic Poultry Flocks in Switzerland and Italy Linked to Soya Expeller.

Poultry feed is a leading source of Salmonella infection in poultry. In Switzerland, heat-treated feed is used to reduce Salmonella incursions into flocks in conventional poultry production. By contrast, organic feed is only treated with organic acids. In 2019, the Swiss National Reference Center for Enteropathogenic Bacteria identified the rare serovar S. Jerusalem from samples of organic soya feed. Further, in July 2020, the European Union’s Rapid Alert System for Food and Feed published a notification of the detection of S. Jerusalem in soya expeller from Italy. During 2020, seven S. Jerusalem isolates from seven different poultry productions distributed over six cantons in Switzerland were reported, providing further evidence of a possible outbreak. Using whole-genome sequencing (WGS), S. Jerusalem isolates from feed and from animals in Switzerland were further characterized and compared to S. Jerusalem from organic poultry farm environments in Italy. WGS results showed that feed isolates and isolates from Swiss and Italian poultry flocks belonged to the sequence type (ST)1028, grouped in a very tight cluster, and were closely related. This outbreak highlights the risk of spreading Salmonella by feed and emphasizes the need for a heat-treatment process for feed, also in organic poultry production.

Antimicrobial resistance in Escherichia coli between conventional and organic broiler flocks

Antimicrobial resistance ( AMR ) is a growing concern for human and animal health. Public awareness of these issues has contributed to increased demand for organic food. In poultry production, there are 3 major production types: no antibiotic ever, organic, and conventional. Organics have been considered safer alternatives that carry fewer antibiotic-resistant bacteria and have less incidence of stable resistance. In this study, we examined the impact of organic and conventional production practices on the resistance patterns of the intestinal microbiome of chickens. Culture and sensitivity analysis performed on the cecal contents were compared between organic and conventionally grown chickens from identical parent stock collected in July and September. The results demonstrated that Escherichia coli isolated from conventionally produced chickens were significantly more resistant to neomycin ( P -value <0.0002) and tetracycline ( P -value = 0.0000) when compared with organically produced chickens in the July collection samples. However, there was no significant difference observed between groups in the September samples. These data demonstrate that AMR patterns of E. coli can differ significantly between organic and conventional chickens in the samples, but AMR pattern among E. coli isolates may not be consistent.

Factors affecting the species of Campylobacter colonizing chickens reared for meat.

To investigate factors influencing Campylobacter spp. colonization of broiler chickens. Campylobacters were isolated from caeca from 319 flocks of two different breeds (199 Cobb and 120 Hubbard), reared as standard (199), Freedom Food/corn fed (57), free-range (47) or organic (16). The standard category exclusively used Cobb birds slaughtered at 38-41days. The Freedom Food/corn-fed and free-range Hubbard birds were slaughtered at 49-56days and the organic flocks at 70days. Campylobacters were picked at random from direct plates. Both breed of chicken (Hubbard) and age at slaughter were independently associated with increased likelihood of colonization by Campylobacter coli rather than Campylobacter jejuni, but breed could not be separated from other aspects of husbandry with the data available. Chickens are frequently colonized by C. jejuni and C. coli and most human infections originate from poultry. In most developed countries approximately 90% of human infections are caused by C. jejuni, but fewer than 10% by C. coli. This might be due to C. coli being less pathogenic than C. jejuni to humans, and/or to chicken meat carrying fewer C. coli than C. jejuni. More investigations are needed into these aspects before it can be concluded that slaughtering older birds from slower-growing breeds would reduce the risk of human Campylobacter disease. Meat from certain breeds of poultry are predominantly colonized by C. coli rather than C. jejuni. More research is needed to understand the impact this may have on the number and severity of human campylobacter infections.

Comparison and assessment of necropsy lesions in end-of-lay laying hens from different housing systems in Denmark

Apperantly healthy laying hens at the end of production (60 to 91 wk) were investigated for the occurrence of pathology and bacterial infections. In total, 7,477 hens from 15 flocks representing the following production systems: Enriched cages, barn housed layers, and organic/free range layers were necropsied. Indications of bacterial infection were investigated by bacteriological cultivation. The overall prevalence of lesions was 16.60%, including lesions of both infectious and non-infectious origin. The most prevalent lesions were bursitis presternalis (6.65%), reproductive tract lesions (e.g., salpingitis and/or peritonitis and/or oophoritis) (3.50%), serosal scarification (e.g., fibrotic adhesive peritonitis) 1.55%, and neoplasm 1.73%. Significant differences were observed between different production systems and/or flocks in the prevalence of reproductive tract lesions, bursitis presternalis, serosal scarification, skin infections, juvenile hens, and traumas/fractures. No significant difference was observed between different production systems in the prevalence of neoplasia, infection of septicemic etiology, and pododermatitis. In total, 3.4% of the hens were out of lay, with significantly higher rate in organic flocks. Infections of the reproductive tract were the most prevalent lesions with bacterial etiology in all productions systems. In total, 40% of the hens with lesions associated to the oviduct were out of lay and significant difference between production systems were observed. Escherichia coli was the most commonly isolated bacteria and in 90% of the cases they were isolated from the reproductive tract lesions. The second most prevalent bacteria was Gallibacteruim anatis. Significant difference in the prevalence of E. coli positive hens was observed between production systems (P < 0.05). In conclusion, the prevalence of reproductive tract lesions in apparently healthy end-of-lay laying was higher than indicated in previous reports. These findings support the previous suggestions that E. coli and G. anatis are the major pathogens causing reproductive tract lesions.

Antibiotic-resistant commensal Escherichia coli are less frequently isolated from poultry raised using non-conventional management systems than from conventional broiler

Poultry production is the fastest growing meat sector worldwide. In the last five years, growing concerns have been expressed by international health agencies and consumers about the transmission of antibiotic-resistant bacteria from poultry meat to human. Consequently, poultry producers have adopted alternative production systems based on reduced antibiotic usage, including organic and antibiotic-free (AF) production. However, the effect of these production systems on the antibiotic resistance of the gut flora in slaughtered poultry has been poorly investigated. We hypothesized that organic and AF production systems reduce the risk of antibiotic resistance in the commensal Escherichia coli of broilers at slaughter compared with conventional production. Cecal content from broilers raised in conventional (292), AF (291), or organic (272) flocks (855 broilers in total) belonging to the same company was sampled. E. coli loads [colony-forming units (CFU/g)] and numbers of E. coli resistant to nalidixic acid (E. colinal) were determined for each sample. Antibiotic susceptibility of one isolate per sample was evaluated using the disc diffusion method; colistin resistance was determined by using the broth microdilution method. The differences in bacterial loads from the three production types were evaluated using one-way ANOVA. Differences in the proportion of resistant isolates in the three production lines were evaluated using Pearson's χ2 or Fisher's test. The strength of the association was evaluated by using odds ratio (OR), with the conventional production type as a reference (OR = 1). Overall, the analysis revealed a high level of resistance (50% or higher) to ampicillin, cefazolin, sulfonamides, nalidixic acid, and tetracycline, independently of the production type. High proportion of ciprofloxacin resistance (52%) was observed, with 4.5% isolates resistant to cefotaxime and 1.8% resistant to colistin. The average loads (log CFU/g cecal content) of E. colinal were determined as 6.84 for AF, 6.38 for organic type, and 7.27 for conventional type. The difference was significant (p < 0.00001). Interestingly, broilers from AF flocks had higher E. colinal loads than broilers from organic flocks. This trend (conventional > AF > organic) was confirmed by qualitative data. However, the magnitude of the effect, measured as a reduced risk of resistance, varied broadly for the antibiotics tested. These findings suggest that poultry production systems alternative to the conventional broiler production are associated with reduced frequency of antibiotic-resistant E. coli among the commensal gut flora, posing a lower risk to the environment and the consumer.

Animal welfare and microbiological safety of poultry meat: Impact of different at-farm animal welfare levels on at-slaughterhouse Campylobacter and Salmonella contamination

Stress factors and poor animal welfare can increase the susceptibility of food-producing animals to diseases, posing microbial risks to consumers. Animal welfare levels, objectively measured with the application of the Welfare Quality® protocol, were assessed in thirteen broiler flocks, including organic ones, to evaluate the presence of statistically significant differences in relation to Campylobacter and Salmonella faecal shedding and consequent microbiological contamination of broiler carcases at slaughterhouse. Each flock underwent animal welfare evaluation the day before slaughtering, followed by Campylobacter and Salmonella detection in faeces (caecal content) and neck skin at slaughterhouse. A total of 1040 samples (520 caecal contents; 520 neck skins) were included in the study. Campylobacter enumeration and Salmonella serotyping were also carried out. The highest welfare scores were reported in organic flocks. Significantly lower Campylobacter concentrations both in caecal content and neck skins (P < 0.05) were reported in organic batches, compared to high welfare conventional batches. Low-welfare batches showed higher prevalence of Salmonella both in neck skins and caecal content, with a statistically significant difference compared to high-welfare batches (43.6% versus 2.9% in neck skins; 19.3% versus 0% in caecal content; P < 0.00001). Salmonella Infantis and Salmonella Bredeney were the most common serotypes, while Campylobacter jejuni and Campylobacter coli were the detected species.This study provides new evidence that high animal welfare standards at farms, other than an ethical issue and a value-add for the end product, could also improve the microbiological safety of poultry meat, ultimately contributing to the protection of consumers.

Differences in antimicrobial resistance of commensal Escherichia coli isolated from caecal contents of organically and conventionally raised broilers in Austria, 2010–2014 and 2016

The prevalence of antimicrobial resistance in commensal Escherichia coli isolated from organically raised broiler flocks was compared to the prevalence in isolates from conventional flocks. From 2010 to 2014, and in 2016, resistance trends and multidrug resistance in isolates from the caecal contents of flocks from both broiler production forms were analyzed. Samples were taken in four abattoirs accounting for at least 90% of the national slaughtered broiler population. In total, 962 commensal E. coli were obtained from organically raised broiler flocks (n = 142) and from conventionally raised broiler flocks (n = 820). The mean prevalence of commensal E. coli isolates, which were fully susceptible to the antimicrobials tested, was 43.3% in organically raised broiler flocks and thus significantly higher (P < 0.001) compared to 16.7% in conventionally operated flocks. During the study period, the proportion of fully susceptible isolates increased significantly in both broiler populations. Antimicrobial resistance rates were significantly lower in commensal E. coli isolated from organic compared to conventional production regarding ciprofloxacin (33.3% versus 69.1%), nalidixic acid (33.7% versus 67.4%), sulfamethoxazole (26.7% versus 39.9%), ampicillin (19.0% versus 33.8%) and trimethoprim (12.8% versus 24.9%). Regarding tetracycline, tigecycline and ceftazidime resistance rates were slightly but not significantly higher in isolates from organic flocks (27.6% versus 25.9%; 4.0% versus 1.4%; 2.0% versus 1.9%). This fact is surprising for tetracycline, as none of the investigated organic flocks had been treated with this antimicrobial during their lifetime. No resistances were found in isolates from both production forms against colistin and meropenem, and from organic flocks against azithromycin. The annual prevalence of resistance against ciprofloxacin and nalidixic acid decreased significantly in isolates from both broiler production forms. In isolates from organic flocks, it also decreased regarding ampicillin and sulfamethoxazole. Significant increasing trends were observed in the resistance prevalence against trimethoprim and borderline significantly for ampicillin in commensal E. coli from conventional flocks. Multidrug resistance was detected at a significantly higher prevalence in isolates from conventionally raised flocks (35.1%) compared to organic flocks (22.7%). Findings from this study clearly indicate the influences of organic compared to conventional broiler production practices on the prevalence of antimicrobial resistance in commensal E. coli from broiler flocks.

Husbandry Practices, Health, and Welfare Status of Organic Broilers in France.

Simple SummaryOrganic poultry production has grown rapidly in Europe for the past several years in the context of sustainable development within farming. The authors carried out a field study in France between 2014 and 2015 concerning 85 organic broiler flocks that showed a wide diversity of farming management systems from independent farmers set up for direct sales of poultry to farmers under contract with a company for product sales. Health and welfare characteristics did not significantly differ between these two farming systems, except slightly dirtier feathers and more footpad dermatitis on the independent farms, related to the poultry housing conditions in mobile houses. A mortality rate of 2.8% was found, with digestive problems mainly being observed. Better knowledge of husbandry practices, health, and the welfare status of organic poultry is of primary importance to improve the management of organic production and to help in characterizing farming sustainability.Organic poultry production has increased sharply with growing consumer demand in the context of sustainable development. A study was conducted in 85 organic broiler flocks between 2014 and 2015 to describe the husbandry practices and the health and welfare status of organic broilers in France, and to study farming diversity by comparing independent farms (Ind farms, n = 15) with direct sales to farms working with companies (Comp farms, n = 70). Each flock was visited at 3 and 11 weeks of age to collect data on farming conditions, health disorders, and mortality. Welfare notation of 30 broilers per flock and parasitic examination of 5 broilers per flock was also performed. Findings showed significantly different farming management between Ind farms and Comp farms, with smaller flocks on the Ind farms (476 broilers/house vs. 3062 broilers/house, p < 0.01) more frequently in mobile houses. The mean mortality rate was 2.8%, mainly involving digestive disorders. Helminths were detected in 58.8% of the flocks. On average, 21.9% and 5.8% of broilers in a flock had footpad dermatitis and dirty feathers, respectively. The health and welfare characteristics of organic broilers on Ind farms vs. Comp farms were not significantly different, except dirtier feathers and more footpad dermatitis on Ind farms (19.1% vs. 2.9%, p = 0.03 and 39.6% vs. 18.1%, p = 0.02, respectively), associated with poultry housing conditions in mobile houses (p < 0.01). This study provides greater insight into farming sustainability aspects related to the husbandry practices, and the health and welfare of organic broilers in France.

Factors related to free-range use in commercial laying hens

Free-range use is expected to contribute to the welfare of laying hens, and more so if a high proportion of the hens in a flock uses the range. In the Netherlands and Switzerland, data were collected about free-range use, genotype, rearing conditions, housing system, management, performance, health, welfare and behaviour in 169 free-range and organic layer flocks by farm visits at an age between 45 and 66 weeks. The aim of this study was to identify which factors are related to free-range use. We analysed the % of hens seen outside when conditions for ranging were optimal (% Hens Out). Based on literature and expert knowledge, 26 potential correlating factors were subjected to preselection. Pearson correlation, independent samples t-tests and one-way ANOVA’s were performed to investigate correlation between the factors and % Hens Out one by one. Twelve factors appeared to be related significantly to % Hens Out and these were entered in a linear regression model: country, production system, genotype, flock size, stocking density, presence of roosters, feather damage, keel bone damage, health at 60 weeks, outside access during rearing, type of ventilation, and amount of daylight in the house. The final model for the total sample explained 47% of the variation in % Hens Out and contained 5 variables. A higher % Hens Out was associated with brown genotype, smaller flock size, roosters in the flock, better feather cover and natural ventilation. Further analyses were done with subsets of the database for either free-range or organic flocks in either the Netherlands or Switzerland. No factors could be found that explained % Hens Out in Dutch free-range flocks. A better feather score and higher amount of daylight explained 44% of the variation in % Hens Out in Dutch organic flocks. Roosters and rearing on the laying farm explained 41% of the variation in % Hens Out in Swiss free-range flocks. Les fearfulness and brown genotypes or more than one genotype per flock explained 33% of the variation in % Hens Out in Swiss organic flocks. The results may contribute to improving range use by laying hens.

Detection of Haemonchus contortus on sheep farms increases using an enhanced sampling protocol combined with PCR based diagnostics

An enhanced sampling strategy for detection of gastrointestinal parasites of sheep based on faecal sampling covering approximately 10% of the animals in the flock was evaluated with focus on the major sheep pathogen Haemonchus contortus. We also compared traditional diagnostics based on faecal eggs counts (FEC) by microscopy with DNA detection on frozen faeces samples using a droplet digital (dd)PCR assay. The investigation was carried out in 2018 in 20 conventional and 19 organic sheep flocks in Sweden with between 70 and 250 production ewes. On 76 different sampling occasions a total of 810 individual faecal samples were collected. Samples were pooled in the laboratory into 270 triplets which were examined both by microscopy and a ddPCR assay. On most farms (95%) a minimum of three triplets were investigated, first from the ewes prior to turn-out and later from the lambs after they had been grazing for at least six weeks. Extra information about the Haemonchus status was provided on 48% of the 76 sampling occasions by including more triplets compared with the old sampling strategy applied in Sweden before 2015 based on two triplets per sampling occasion irrespective of flock size. At a farm level H. contortus was identified by microscopy in 22 (56%) of the 39 flocks and by ddPCR it was found in 28 (72%) flocks with the enhanced protocol. There was a substantial agreement between the two diagnostic tests (Cohens kappa=0.70±0.087). No significant differences in infection levels were observed between the two production systems (conventional and organic) irrespective of the diagnostic method used. However, samples from the ewes were more often Haemonchus positive than those from the lambs indicating that the level of parasite control was in general acceptable. Combined, our results show that Haemonchus infection is widespread throughout Sweden. In conclusion, we have validated a practical tool for sheep producers to assess Haemonchus infection with high precision.

Welfare assessment of conventional and organic broilers in Denmark, with emphasis on leg health

The aim of this study was to survey and report the walking ability in broilers housed in both conventional and organic production systems in Denmark. To this end, the authors...

High prevalence of Brachyspira spp. in layers kept in alternative husbandry systems associated with frequent species variations from end of rearing to slaughter

ABSTRACTA longitudinal survey was conducted to investigate the presence of Brachyspira species in layer flocks. A total of 66 layer flocks kept in alternative husbandry systems were sampled at three time points: end of rearing, at peak of lay and at end of lay. Content from caecal samples of freshly killed birds was cultured at each sampling time point and processed for further investigations. Gross pathological lesions in caeca were recorded during post mortem investigation. Spirochaetes were isolated from 50 flocks: three flocks were positive at all three sampling points, 25 flocks at two and 22 flocks at one sampling point, respectively. The presence of Brachyspira spp. could not be related to specific gross pathological caecal lesions or antibiotic treatments. The number of positive flocks increased with the age of birds. Furthermore, organic flocks were more often positive than flocks from barn systems. In total 80 spirochaetal cultures were obtained. B. intermedia (43.8%) was the most common species, followed by B. pulli (13.8%) and B. pilosicoli (12.5%). Brachyspira murdochii and B. innocens were found in 5.0% and 2.5%, respectively, whereas 11.3% of Brachyspira isolates could not be identified to species level. In 11.3% of the samples mixed infections were detected. Finally, the longitudinal survey revealed for the first time a possible shift in the Brachyspira species in a substantial number (32%) of layer flocks during their lifetime.

Transmission dynamics of extended-spectrum β-lactamase and AmpC β-lactamase-producing Escherichia coli in a broiler flock without antibiotic use

Extended-spectrum and AmpC β-lactamase-producing Escherichia coli (ESBL/AmpC-EC) are found throughout the broiler production pyramid. Transmission of resistance between broilers and humans could occur at any point, representing a potential public health issue. Insight in farm transmission dynamics could provide a basis for control, leading to fewer contaminated broilers. The aim was quantifying transmission rates and routes of ESBL/AmpC-EC, and specific phylogenetic groups, in an organic broiler flock without antibiotic use. In each of two consecutive production rounds, 80 randomly chosen broilers were followed individually. Cloacal swabs from these, 20 other randomly chosen broilers, and 11 environmental samples were taken at several moments from arrival till slaughter. ESBL/AmpC-EC were isolated by selective pre-enrichment, and ESBL/AmpC-genes and E. coli phylogenetic groups were determined. Transmission parameters (β) were estimated using a Generalised Linear Model with a susceptible-infectious-susceptible model. Effect of direct broiler contact as compared to contact through the environment and previous carriage c.q. infectious status and their interaction were included as explanatory variables. Multiplying β by the length of the infectious period gives the reproduction ratio (R). On day 1, prevalence was 28.8% (95%CI 19.2–40.0%) and 0.0% (95%CI 0.0–4.5%) among individually followed broilers, in round 1 and 2 respectively. In round 2, the environment was positive before arrival of day-old chicks. After 3 days, almost 100% of broilers and environmental samples were positive in both rounds. Most samples were positive for CTX-M-1 group genes, and A1 and B1 were predominant phylogenetic groups. From day 3 there was a shift towards more phylogenetic groups. R was 1.70 (95%CI 0.55–5.25) for total ESBL/AmpC-EC. Risk for broilers to become infectious was lower if previously infectious (βpreviously infectious=0.02 vs. βnot previously infectious=3.41; P<0.0001). For phylogenetic groups separately, R was 0.88 (95%CI 0.38–2.07), 0.51 (95%CI 0.27–0.98), 0.99 (95%CI 0.65–1.51) for A1, B1 and rest (i.e. A0, B2, D1, D2) groups, respectively. The interaction effect for A1 and B1 was reflected in the fact that when broilers were previous infectious, the environment was relatively more important for transmission of the A1 group, while this was direct contact between broilers for the B1 group. Positive day-old chicks and the environment both play a role in introduction and transmission of ESBL/AmpC-EC in flocks. These results suggest that, even without selective pressure from antibiotics, total ESBL/AmpC-EC persistence, and resulting endemic situation, seem to be caused by shifts in carriage of different phylogenetic groups. It implies that contaminated broilers enter the slaughterhouse.

Prevalence, genotyping and risk factors of thermophilic Campylobacter spreading in organic turkey farms in Germany.

BackgroundThe need for organic food of animal origin has increased rapidly in recent years. However, effects of organic animal husbandry on food safety have not been rigorously tested especially in meat turkey flocks. This study provides for the first time an overview on the prevalence and genetic diversity of Campylobacter species (spp.) in five organic meat turkey farms located in different regions in Germany, as well as on potential risk factors of bacterial spreading. Thirty cloacal swabs as well as water samples and darkling beetles were collected from each flock and examined for the presence of Campylobacter by conventional and molecular biological methods. The isolates were genotyped by flaA-RFLP.ResultsCampylobacter spp. were detected in cloacal swabs in all 5 turkey flocks with prevalence ranged from 90.0 to 100 %. 13 cloacal swabs collected from birds in farm III and IV were harboured mixed population of thermophilic campylobacters. In total, from 158 Campylobacter isolated from turkeys 89 (56.33 %) were identified as C. coli and 69 (43.76 %) as C. jejuni. Three Campylobacter (2 C. jejuni and 1 C. coli) were detected in drinkers of two farms and 3 C. coli were isolated from darkling beetles of one farm. No Campylobacter were isolated from main water tanks. flaA-RFLP assay showed that turkey farms can harbour more than one genotype. In a single turkey two different genotypes could be detected. The genotypes of campylobacters isolated from water samples or beetles were identical with those isolated from turkeys. No effect was found of some environmental parameters [ammonia concentration (NH3), carbon dioxide concentration (CO2), relative humidity (RH) and air temperature)] on Campylobacter prevalence in organic turkey farms. Additionally, drinking water and darkling beetles might be considered as risk factors for the spreading of Campylobacter in turkey flocks.ConclusionsThis study highlights the high prevalence and genotypic diversity of Campylobacter spp. isolated from organic turkey flocks. Further research is needed to assess other potential risk factors responsible for bacteria spreading in order to mitigate the spread of Campylobacter in organic turkey flocks by improving biosecurity control measures.Electronic supplementary materialThe online version of this article (doi:10.1186/s13099-016-0108-2) contains supplementary material, which is available to authorized users.