INTERDIGITAL SKIN TEST FOR EVALUATION OF DELAYED HYPERSENSITIVITY AND MONITORING CELL-MEDIATED IMMUNE RESPONSES IN

**Original scientific paper Abstract: A skin test to assess cell mediated delayed hypersensitivity (DH) used to evaluated immune response of chickens. Results of many study indicated, that skin testing is especially useful as a simple in vivo screening to evaluate normal and suppressed T-cell mediated DH. Chickens were sensitized with using mitogens, B and T-cell dependent antigen by intradermal injection. The most feathered skin of chickens is too thin for adequate intradermal injections, so the wattle is the standard site for skin testing, however, in younger than 2 or 3 weeks old chickens, the wattle is undeveloped and intradermal injection and measurement of response are difficult. A simple interdigital skin used by many of the authors. Skin swelling response and DH reaction were measured in mm before injections and after. The skin test and DH in vivo results oedema-initiating characteristics of sensitizing agents, which increase in skin thickness detectable after 4- 6 hours of application. Many of investigation results suggests that healthy chickens are able to have strong immune response and support the concept that some changes in the cell-medieted immune response and other pathogens may potentially affect immune response. Key words: skin test, delayed hypersensitivity, immune respons

The influence of bovine seminal plasma on BHV -1, EHV-1, BVD and Morbus Aujeszky virus replication in vitro

The aim of this investigation was to estimate the possible influence of bovine seminal plasma (BSP) on the replication in vitro of some sexually transmitted viruses: BHV - 1 (bovine herpes virus - 1) and BVD (bovine viral diarrhea) significant for bovine reproduction. In addition, we tested the influence of the on EHV-1 (equine herpes virus - 1) and Morbus Aujeszcky virus replication in the same model. Our results showed that BSP has an inhibitory effect on the replication in vitro of all tested viruses and their strains. This activity was lost following dialysis suggesting that the active inhibitory factor is of small molecular veight (less than 12 kDa).Furthermore, inhibition was preserved after repeated freezing and thawing and after inactivation for 30 min at 56 °C indicating that the inhibitory factor is heat stable

Efficacy of recombinant VAXXITEK HVT-IBDv vaccine against very virulent Infectious bursal disease virus (vvIBDv) challenge in layer chicks: A pilot study

The infectious bursal disease virus (IBDv) is widespread in poultry flocks all around the world. Various biotypes have emerged and because of that, adequate management practices and vaccination of chicks are of paramount importance for the protection against field strains. One day old Lohmann Brown chicks were vaccinated with intermediate vaccines and the recombinant VAXXITEK HVT-IBDv vaccine formulation, and challenged at 48 days of life with the very virulent IBDv (vvIBDv) strain CH/99. The best protection (100%) was achieved with the recombinant vaccine administered by the subcutaneous or intramuscular route at a day old, while intermediate and intermediate plus vaccines protected 80% of birds from clinical symptoms. The highest bursa body ratio (5.33, 3.50 and 4.12) was accomplished in non-vaccinated and non-challenged birds and birds vaccinated with the VAXXITEK HVT-IBDv vaccine. The recombinant VAXXITEK HVT-IBDv vaccine has provided protection for commercial chicks against challenge with the vvIBDv strain in this experiment. Under field conditions, additional vaccination is possibly needed with supplementary application of live attenuated vaccines. However, the recombinant vector vaccines are providing significant aid against clinical signs and immunosupression caused by the vvIBDv