Detection and Analysis of Pseudorabies Virus gI antibody in an Extensive
Pig Farm from 2015 to 2018
Abstract
PR is an endemic disease in most regions of China, but the report about
the dynamics of PRV gI antibody in one farm was rarely. In order to
analyze the dynamics of PRV gI antibody in one farm, 1513 serums from
the different pigs in a farm were collected to detect the gI antibody by
ELISA. The results in July 2015 indicated only the gilts were PRV gI
antibody positive, and the other pigs were all PRV gI antibody negative.
But the brain PRV gE gene from 10 piglets were almost positive, their
PRV gI antibody were all negative. The results from October 2015 to July
2018 indicated that in the boar herd, 3 positive individuals were found
in October 2015 and subsequently they were culled. In the following
tests, the boar herd always kept the negative state. The positive rate
in the sow herd was always more than 70% from October 2015 to October
2017. In January 2018, the positive rate decreased to 27%, but it was
up to 40% and 52% in April and July 2018. For 100-day pigs, the
positive rate obviously decreased in October 2016 and then always kept
less than 30% in the later detection. For 150-day pigs, the positive
rate obviously decreased to 16% in January 2017 and transferred to the
negative in July 2017. The positive trends from the 40-day pig to the
150-day pig were all remarkably decreased in three tests in 2018. These
results indicate that the serological detection is not appropriate in
the early stage of the PRV infection, and the introduction of gilts is a
risk factor for a PRV-negative farm. The dynamic data of the PRV gI
antibody provide the reference for the farm that want to carry out the
PR eradication program.