|dc.description.abstract||Background: One of the biggest challenges in the eradication of PRRS in
Hungary’s pig herds was the eradication from large-scale farrow to finish farms.
Among the methods used for this purpose, the depopulation-repopulation is
obviously the safest, but also the most expensive procedure.
Objectives: Specialists have continuously strived to develop a method and to
apply it under Hungarian conditions, which enables the immunization of the
breeding stock, but ensures virus-free rearing for the entire life stage of the
offspring. Since 2017, the international regulations of PRRS have provided the
opportunity for this.
Materials and Methods: Studies were carried out on a pig farm with 850 sows,
from farrowing to slaughter, located in the county with the highest density of pigs
in Hungary and the one most infected with PRRS in 2014. The farm was infected
with the disease until 2016, and then in 2016-17, with a complete depop-repop
with high animal health status was put into production. At the beginning of 2018,
the farm was infected with a strain of the PRRS virus that did not occur in the
previous herd. During the eradication of this herd, the mass vaccination of the
breeding stock was carried out quarterly. The effectiveness of the vaccination
in the progeny was checked with laboratory tests (PRRS ELISA, PRRS PCR DIVA),
and with these tests the time when the immunization of the progeny could be
stopped was precisely determined. At the same time, the methods of internal
epidemic prevention were regularly revised.
Results and Discussion: In 2021, the farm met the official requirements of
a free, vaccinated pig farm from farrowing to slaughter, for which it received a
certificate. The authors present the evolution of some reproductive biological
indicators (stillbirths and live births per farrowing) during the phases of infection