A study from Denmark has confirmed previous findings that vaccinating with Circovac can improve the reproductive performance of sows by up to one piglet per litter. Presented at Merial’s Swine Forum in Budapest, the research also showed that a vaccination program to control porcine circovirus type 2 (PCV2) can help reduce antibiotic use. 

Dr. Dorte Risum from the Porcus Swine Practice in Denmark presented the findings of a study on a 220 specific pathogen free (SPF) sow farm which had mycoplasma, but not porcine reproductive and respiratory syndrome (PRRS).

In 2009, there were problems regarding discharge post-farrowing, and there was an increase in the number of stillbirths from 1.4 to 2.0 per litter. The number of live births remained unchanged at 14.9 per litter.

Improved post-farrowing management and treatment with penicillin solved the discharge problems, but did not have any effect on number of live or stillbirths. In the same period, despite high growth rates, weaners became less uniform in size, and antimicrobials were being increasingly used to try to address these health issues.


Blood samples were negative for PRRS and Leptospirosis. PCV2 was suspected and it was decided to vaccinate all sows and gilts against PCV2 with Circovac, a two-shot vaccine approved for sow and gilt vaccination. Sows were vaccinated six and three weeks prior to farrowing. Gilts were vaccinated with Circovac six and three weeks prior to breeding.

After vaccination the live born rates rose from 14.9 to 15.8, and stillbirths reduced from 2.0 to 1.5 per litter. When piglets from vaccinated sows were weaned, they were more even in size. As a result, the use of antimicrobials declined. 

Findlay MacBean, Merial Animal Health’s head of Large Animal Business, said: “The results from this study are consistent with similar studies carried out in the U.K., which demonstrated that vaccinating sows against PCV2 can result in an extra piglet per sow per litter.”