Pig Health Featured Articles
Consistent improvement of reproductive performances following CIRCOVAC® vaccination
By Merial - Following the provisional licensing of CIRCOVAC® in Germany in 2004, an improvement of reproduction performances was consistently reported by farmers and veterinarians, without any history of reproductive failure associated to PCV2.
Large-scale field study
A large-scale field
study was set-up to assess this unexpected
effect. 277 sow-farms that had been using
Circovac® for at least 6 months were included
(Joisel, 2008).
The data collected covered the
period from one year before vaccination and
6 to 12 months after the first vaccine injection.
A significant improvement was observed for
all reproduction parameters analysed (see
table 2), except for the number of stillbirths.
On average, the number of piglets weaned per sow per year increased by 1.13 (p=0.0001). Similar data, obtained from pig farming organizations over the same period, did not show an improvement of performances in the German Swine industry. These results are statistically powerful, owing to the number of farms included in the study. In Denmark, another large-scale study also confirmed the positive effect of Circovac® vaccination on productivity.
34 Danish herds analysed
In 34 PMWS-positive
Danish herds, a farm record analysis included
a total of 14,510 sows (Kunstmann & Lau
2008). The herds started vaccinating between
July 2006 to May 2007, 30 of them using a
mass vaccination programme.
The number of
piglets weaned per sow per year increased
after vaccination, and returned to national
levels. This also applied to the wean-toslaughter
mortality rate, after 2 to 5 months
(see table 3).
Three other PMWS-positive
herds from North Jutland (Denmark) observed
the same positive effect of Circovac® vaccination
on sow performances. All of them started
Circovac® vaccination in May 2007.
Performance parameters from October 2006
to November 2007 were analysed, and were
expressed as an average of monthly results
before and after vaccination (Bech &
Kunstmann 2008). In all three herds, returnto-
oestrus rates were better than the national
average. Vaccination improved all reproductive
performances (see table 4), and return-toestrus
was improved even further.
Taken together, these studies confirm that
PCV2 may impair reproductive performances
in a subclinical way, probably independently
from the occurrence of PMWS in the progeny
of these animals. They also convincingly
demonstrate that consistent Circovac® vaccination
helps in alleviating this "circoviral"
effect.
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Extracted from Merial's Newsletter: Circonews June 2008Click here to download this newsletter (1Mb PDF) |
July 2008
