Today's high performance in the industrial poultry industry would not have been possible without the focused specialization of production and the use of highly productive poultry crosses. Therefore, the organization of modern poultry farming used simultaneously with high productivity indicators leads to a decrease in natural resistance and an increase in the susceptibility of birds to various pathogens of infectious diseases transmitted aerogenically, which is accompanied by the manifestation of respiratory syndrome in birds. One of the key reasons for the development of respiratory syndrome is the circulation of pneumovirus in the herd, which is especially dangerous for meat farms, since in broiler chickens the disease proceeds in a more severe form compared to poultry crosses.Avian metapneumovirus infection causes significant economic damage to poultry farming, which consists of losses from a decrease in safety and productivity, as well as the cost of health and preventive measures.4 subtypes of MPV are officially known, although recent publications have reported of two new pneumoviruses, GuMPV and AMPV PAR-05 isolated from the seagull in North America.The diversity of pathogen subtypes and differences in virulence properties of metapneumovirus create difficulties both in the prevention of this disease and in its diagnosis.Difficulty of metapneumovirus isolation from the examined material is caused by the short period of virus persistence in the organs of birds.The most effective method of controlling avian MPVI is vaccination.
Introduction. Chicken cholera is one of the most dangerous avian infectious diseases, causing significant economic damage to the industrial poultry production. Chicken cholera usually occurs in septic form, and causes high morbidity and mortality (60–80%), but recently it has become chronic, subclinical and associated. Inactivated emulsion vaccines are used worldwide to prevent chicken cholera and provide high and long-term immunity. However, there is a problem with residual reactogenicity of inactivated vaccines, particularly of the bacterial variants. This problem can be solved by using safer, next-generation adjuvants. The aim of the article is to study the physical and biological properties and determine the optimal inoculation volume and method of administration of inactivated vaccines against chicken cholera , based on different adjuvants.Materials and methods. Formaldehyde inactivated culture of P. multocida st. 115and a number of adjuvants (“Montanide GEL-02” and oil adjuvants “Montanide ISA 70 VG” and “Montanide ISA 78 VG”) were used for vaccine production. The vaccine samples were tested for sterility, stability and viscosity by conventional methods. Determination of reactogenicity and antigenic activity of the vaccines was carried out on young 30-days old chickensof egg-laying type.Results. The vaccine sample based on the adjuvant “Montanide ISA 70 VG” containing 1.5 billion P. Multocida microbial cells in a single immunizing dose of 0.3 cm3 was found to be the best among the tested preparations. When assessing the reactogenicity, it was obvious that all samples, regardless of the type of adjuvant, showed more pronounced residual reactogenic properties when injected intramuscularly into the chest muscle than when injected subcutaneously into the middle third of the neck.
Studies carried out in many countries of the world demonstrate considerable variability in the virulence properties of pasteurellosis. The variety of antigenicity and toxicity serovars of the pathogen determines a number of specific features of display of poultry pasteurellosis, especially in associated infections when several causative agents of infectious diseases of bacterial and/or viral etiology circulate in one farm. In mixed infections, birds show a variety of clinical signs, most notably a respiratory syndrome characterized by respiratory involvement (sinusitis, conjunctivitis, laryngitis, tracheitis, bronchitis, pneumonia, and aerosacculitis) and tissue swelling in the suborbital sinuses, intermandibular spaces, and ear flaps.This situation makes it difficult to timely and promptly conduct effective therapeutic and anti-epizootic measures. However, it is necessary to identify the etiology of the disease as soon as possible, methodically and comprehensively, taking into account epizootic data, clinical signs, pathological anatomical changes and with obligatory confirmation by laboratory tests.At present time laboratory methods for diagnostics of avian pasteurellosis are regulated by Methodical instructions (MI) on laboratory diagnostics of pasteurellosis of animals and birds approved by the Chief Veterinary Department on August 20, 1992 № 22-7/82.According to the approved MI, the laboratory diagnosis of avian pasteurellosis includes microscopy of smears and fingerprints, isolation of pasteurella cultures and their identification, and, if necessary, bioassaying.It should be noted that the laboratory diagnosis of pasteurellosis according to the MI is a laborious and time-consuming process.Apart from the methods described in the MI, the serological method - enzyme immunoassay (ELISA) and molecular biological method - polymerase chain reaction (PCR) are currently widely and successfully used in laboratory practice for diagnosis of avian pasteurellosis, which are not reflected in the approved MI, but allow relatively simple and rapid reliable results.
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