Field observation: No adverse reactions after PRRS EU mass vaccination of sows

Because of presumed side effects, Dutch farmers are often unwilling to vaccinate sows in first month and in the last weeks of gestation. In 2015 a new PRRS vaccine for sows is introduced for the Dutch market (ReproCyc® PRRS EU, Boehringer Ingelheim), which is recommended to use in 3 to 4 mass vaccinations of the sows per year.

This is an evaluation of adverse reactions after mass vaccination of sows with ReproCyc PRRS EU under field circumstances.

In a Dutch 1300 sow herd with a weekly rhythm, pregnant sows are housed in 3 dynamic groups of 350 sows. Sows enter the groups within 5 days after insemination.

ReproCyc PRRS EU mass vaccination took place at 30 June 2015 and 5 October 2015. For one week before to one week after the October mass vaccination daily records were kept of sows that did not consume their daily feed ration at the Electronic Sow Feeders (ESF) (Manibeck, Pigtek).

Parameters obtained from the management system (Agrovision) were: percentage of re-breeders (weekly) from 4 weeks before to 4 weeks after mass vaccination, and the percentage of pre-weaning piglet mortality per month (year to date).

After the mass vaccinations no adverse reactions were seen by the farmer and his staff.

The percentage of sows that did not eat their daily ration varied from 0,2 to 1,1%, with 0,5% on the day of vaccination and 0,3% the day after.

The percentage of re-breeders per week varied between 10,0 and 22,5%, in the 4 weeks before and 4 weeks after mass vaccination at 5 October the average was 17,1% and 15,6% respectively.

Pre-weaning mortality varied from 7,1 to 10,2% per month, in the month following mass vaccination this was 8,8% and 8,4% respectively.

Any effects on feed intake can be expected within two days after vaccination, this was not observed after mass vaccination.

We assumed that effects of re-breeding could be expected in the weeks following vaccination. No increase of re-breeders was observed.

When sows do not feel well we assumed the sows to have more problems fostering their piglets, leading to an increase in pre-weaning piglet mortality. No increase of mortality after vaccination could be observed.

The results of this evaluation show a good safety of ReproCyc PRRS EU used in mass vaccination in sows, which is in line with other studies.

Disclosure of Interest: None Declared.