Avian metapneumovirus (AMPV), formerly known as avian pneumovirus (APV) is epizootic agent of turkey rhinotracheitis (TRT) and swollen head syndrome (SHS) in turkeys and chickens. The infection primarily affects the upper respiratory tract of young birds (broilers), while also decreases egg production of adult hens. Thus, the development of infection in susceptible birds of any age can cause serious economic losses. The purpose of this study is to test serums from broilers and hens for the presence of antibodies against the avian metapneumovirus. In this series of studies 317 serum samples taken from one 1 day to 75 weeks old birds were tested. Thus, on the basis of serological tests of blood serum and of chicken flocks and broilers, we had a preliminary diagnosis on the presence of avian metapneumovirus infection. Serological studies of unvaccinated against avian metapneumovirus infection bird flocks using the ELISA method showed antibody titers on average at 22 859 ± 4133. Avian metapneumovirus infection in birds was accompanied by a decrease in egg production of chicken flocks by 8.0 - 12.8%.

Avian mycoplasmosis have been considered a severe problem in poultry diseases; Mycoplasma gallisepticum being one of the most important. This study was conducted in Joint-Stock Company Balticovo, Latvia, to determine the prevalence of M. gallisepticum infection in hen’s flocks in the farm. A total of 904 serum and 335 swab samples from non-vaccinated birds against M. gallisepticum from 65 chicken flocks of different age, from day 1 to 75 weeks old, were all tested. The commercially available enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) tests were used. Results revealed that the seropositive flock rate, based on ELISA tests and, according to ratio that represents the extent to which a light source effectively stimulates the rods: S/P ratios and antibodies titer higher 1.076 were 22/904 (2.43%) and 4/904 (0.44%), respectively, while PCR-positive flock rates were not confirmed. Seroprevalence of M. gallisepticum in commercial layer flock in Latvia was more common seen in birds from 17 to 30 weeks of age.