Backyard poultry in Serbia: diseases and biosecurity

Due to the increasing demand for poultry products from traditional farming systems, the growing trend for keeping chickens in alternative production systems has also been observed worldwide. Different types of extensive systems such are organic production, low-input production systems, and free-range systems have experienced significant growth in response to this trend in our country. The Government of the Republic of Serbia, within the framework of the Program for the Preservation of Autochthonous Genotypes, supports the development of extensive rearing systems for poultry in the form of significant annual subsidies. We have three types of backyard farming systems: permanent confinement, free-range, and mixed confinement. Mixed confinement is the most frequent system and implies, the birds scavenge freely in the courtyard of the farmer’s house during the day, and at night they are kept in an improvised house (hennery or chicken coop). These rearing systems often consist of free, native, unselected breeds of various ages, mixed with different poultry/bird species in the flocks. They are less standardized than intensive-rearing systems. In addition, not enough attention is paid to the need to protect backyard poultry. Most of these birds are kept outdoors where the birds forage around the house or in the backyard during the day. Access to the outdoors brings poultry into contact with wild birds and other animals that can carry various diseases. The results from our laboratories showed that due to poor or absent disease control strategies and inadequate hygiene, in the last 7 years, the most frequent cause of outbreaks and high mortalities of backyard poultry in Serbia were pathogens such as bacteria (E. coli, Clostridium perfringens), viruses (Marek's disease virus, Avian leucosis virus), fungi (Aspergillus spp.) and parasites (Ascaridia galli, Eimeria spp, Dermanyssus gallinae). Vaccination against Marek's disease virus is not legally binding; therefore, this diseas