Escherichia coli (E. coli) is one of the most common bacterial causes of infection in poultry farming. Whether the infection is localized or systemic, a primary or secondary disease, it is most frequently treated through the application of wide-spectrum antimicrobials. Excessive use of antimicrobials in agriculture is significantly contributing to the worldwide rise of antimicrobial resistance, but is also very expensive and often ineffective in the long term. Here, we present a case where a colibacillosis outbreak on a family farm of laying hens was treated using an autogenous vaccine. The birds had septicemia, cellulitis, and severe skin wounds. They were not vaccinated against E. coli, and did not receive any antimicrobials previously. E. coli strains were isolated from the daily mortalities on the farm and used for preparation of the vaccine. Each bird was given an intramuscular injection of the autogenous vaccine. The immunogenicity of the vaccine was tested by the determination of specific antibody levels in the sera of the birds using the in-house ELISA. Shortly after vaccination, the morbidity and mortality rates significantly decreased, and egg production was improved. The application of the autogenous vaccine served as a curative and preventive measure, and has proven to be a very efficient method of antimicrobial therapy.

Fungi are present in abundance in poultry housing. The aim of the study was to assess the effect of season and microclimate parameters in poultry housing on fungal flora in the air and broiler trachea in commercial fattening conditions. The study was conducted in summer and winter. Study results indicated seasonal impact and association between fungal flora composition in housing air and broiler trachea. However, the total fungal count in housing air was significantly higher in summer and in broiler trachea in winter, both significantly correlated with indoor relative humidity and ammonia concentration. There was no significant correlation between outdoor and indoor air temperature, relative humidity and airflow rate, respectively. Study results suggested that environmental determination of fungi should be accompanied by their determination in broilers. In addition, seasonal impact on fungal contamination should be associated with microclimate conditions in the poultry house rather than the season itself. The fungi detected and the results obtained have implications not only for broiler health but also for the health of humans working in such environments.

This study aimed to investigate dust and bacterial air contamination in a broiler house during different seasons. The study was carried out in commercial housing conditions during five weeks of the rearing cycle in summer and winter. The total dust concentration ranged from 1.90 to 4.50 mg/m³ in summer and from 2.80 to 5.10 mg/m³ in winter. The total bacterial count ranged from 2.85 × 10⁴ to 1.03 × 10⁵ CFU/m³ in summer and from 2.12 × 10⁴ to 2.28 × 10⁵ CFU/m³ in winter. The study results showed the dust concentration to be increased in winter as compared to summer, yielding a significant correlation (r = 0.602, p < 0.05) with a significantly higher airborne bacterial count in winter (p < 0.001). Furthermore, dust concentration showed significant correlations (p < 0.05) with air temperature (r = −0.418), relative humidity (r = 0.673), and broiler activity (r = 0.709), while bacterial count yielded significant correlations (p < 0.05) with air temperature (r = −0.756), relative humidity (r = 0.831), and airflow rate (r = 0.511). The results obtained in the study can prove useful in the field. Seasonal variability in dust and bacterial air contamination should be considered in the development of guidelines or standards of air quality in broiler housing and evaluation of the effectiveness of remedial strategies.

Poultry red mite (PRM), Dermanyssus gallinae, causes egg drop production, anemia and can be a vector in transmitting diseases. The PRM control mainly focuses on usage of the conventional chemical biocides. The objective of this study was to analyze the farmers’ perception regarding the impact, management and control of PRM in Macedonian layer farms. The data were collected with direct on-site visits using a unified questionnaire. In total, 29 poultry farms (28% of farms in the country), all with conventional cages, were part of this study. The data were analyzed by descriptive statistics, inferential statistics and Naïve Bayes Classifier technique. In 30% of the poultry farms the farmers had observed that the flock was infested with PRM. In total, 32 different treatments against PRM were reported from the farmers, and three of them were non-biocide treatments. The most used biocides (17% of the farms) were crude oil, Formalin, Neopitroid^® and disinfectants. The highest agreement regarding biocides application among the farms (38%) was before the production starts. Most of the farmers applied biocides routinely, before the infestation is evident (75%). The median costs for PRM treatment were 175€ per flock, higher in the infested farms 493±677€ compared to non - infested 100±71€, p<0.05. None of the Macedonian farmers included in the study was using monitoring method for PRM infestation, contributing to poor data records. This study highlights the need of developing unified strategy for PRM control included in the Integrated Pest Management in poultry layer farms.

Background: Zoonotic Chlamydia (C.) psittaci, can be found in different bird species, but also in other animals and humans. Recently, new species have been described, as C. gallinacea and C. avium, changing the perspective of a single causative agent of avian chlamydiosis. Genotypes of C. psittaci differ, according to their pathogenicity, and the ones isolated from parrots, turkeys and ducks are particularly pathogenic to bird breeders or owners, veterinarians, poultry farms and slaughterhouse workers. Infections in humans may pass unapparent or to the onset of systemic lung inflammation. Asymptomatic infection is most commonly found in birds, but acute systemic or chronic infections are also possible. Material and Methods: Presence of C. psittaci in birds in Croatia must be reported by law, and all registered flocks of pigeons, parrots and other birds must be examined once, and pet shops at least twice a year. In the period from 2008 to 2017, a total of 3283 avian samples were examined by real-time PCR and the presence of Chlamydiaceae, C. psittaci and C. gallinacea were detected in faecal samples or swabs. Results and Conclusions: In total, 12% of the samples were found positive for Chlamydiaceae. From the 2015, the presence of C. psittaci has also routinely been determined, whereas 34.01% positive avian samples proved to be C. psittaci. Findings of chlamydia in various avian species indicates the importance of proper implementation of the protective measures, by taking into account the zoonotic potential of chlamydia originating from birds and poultry.