ABSTRACT Clinical manifestation of the disease caused by the chicken anaemia virus (CAV) occurs when chicken chicks are vertically contaminated or before the second week of life. CAV control is based on the vaccination of broiler breeders in order to promote progeny protection through maternal antibodies. This work aims to evaluate, under field conditions, the antibody title in commercial broiler breeders at 28, 48, and 68 weeks of age, the rate of transference to the progeny, as well as the duration of antibodies in the progeny up to 21 days of age. Thus, a total of 92 sera samples from 93,000 broiler breeders vaccinated with a live vaccine for CAV at 14 weeks of age and 366 sera samples from their respective progeny were analyzed using ELISA. Breeders’ antibody title for CAV ranged between 5051 and 8660, and these titles may provide sufficient protection for their progeny. On average, 63% of the maternal antibodies were transferred to the progeny and lasted up to the second week of chick’s life. It is possible to conclude that the vaccine and the vaccination procedure used by this company for breeders against CAV seems to be effective in inducing high antibody levels in the breeders and transfering protective maternal antibodies to the progeny.

ABSTRACTAvian encephalomyelitis is caused by an Hepatovirus and primarily affects chickens. Chickens of all ages are susceptible to the virus, but the nervous symptoms are manifested only in young chicks, between one to five weeks of age. During the last thirty years, avian encephalomyelitis appeared to be well controlled by breeder vaccination. However, the increase of the number of cases is causing concern in the poultry industry. In the present study, we performed a retrospective analysis of the cases presenting histological lesions compatible with avian encephalomyelitis in broilers. The evaluated cases affected broilers from one to 35 days old from the southern region of Brazil. Only cases with compatible microscopic lesions and associated with clinical symptoms in the field were considered. In addition the histopathological diagnosis, sera were tested by ELISA (Enzyme-Linked Immunosorbent Assay). Considering the clinical, histopathological, and serological evidences, the disease was confirmed, showing an increase in outbreaks from the last quarter of 2012, extending through 2013. The cause of this increase is not clear, although we suspect vaccine or vaccination error. Enhancing vaccinated breeders flocks monitoring before the beginning of egg production and/or using a protocol with two vaccinations is recommended.

Serum is widely used for the purpose of monitoring and diagnosis support for most of poultry diseases. In the case of the serum plate agglutination test (SPA), commonly used to detect antibodies for Salmonella Pullorum (SP), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS), serum cannot be frozen because it may result in false positive. Without freezing, serum can last only for a few days. In this experiment, glycerin was evaluated as a serum preservering agent. About 50 samples for each disease and analyzed by SPA test previously were separated. Glycerin was added to serum from commercial chickens, with and without antibodies for SP, MG and MS, in the proportion of 1:1 (serum:glycerin) and kept at refrigerated conditions (2 to 8 ºC). For four years they were tested by the SPA, initially weekly, afterward monthly and then annually. The results show that serum with glycerin give consistent and valid results according to the kind of antibodies present for the period tested. Sera that glycerin was not added to, the results were valid only for the first week. From the second week on, microbial growth affected the test results of the sera without glycerin. Our investigation shows that glycerin can be used to preserve chicken serum for SPA under refrigerated conditions. It is an easy, simple and cheap procedure that can extend serum shelf life, useful mainly for control sera.

Contamination of ISA BROWN layer hens by Salmonella spp. and serotyping of the isolated strains were performed in 30 farms. Salmonella detection was done from feces and cloaca swabs. Eggs produced in the farms contaminated by Salmonella spp. were analyzed by culturing the shell rinsing and egg yolk. Salmonella spp. was isolated in eight (23.0%) farms, but was not detected from eggs. S. Enteritidis, which is the most prevalent sorotype associated to human salmonelosis in Paraná State, was not isolated either from birds or eggs analyzed. The sorotypes isolated were Salmonella enterica subsp. enterica (0:3.10) (67.0%), Mbandaka (11.0%), Infantis (11.0%), and Newport (11.0%).