Reducing PCV2 viremia in neonatal pigs through sow mass vaccination in a unstable herd

Introduction:

In utero infection of piglets with PCV2 may serve as a potential source of PCV2 vertical transmission to the offspring1. This infection might make newborn pigs more susceptible to co-infections with other pathogens and therefore may be associated with PCVAD in the growing pig2. It has been shown before that Ingelvac CircoFLEX® is safe when used in sows 3. The objective of this study was to determine the prevalence and viral load of PCV2 viremia in pre-suckle piglets before and after sow mass vaccinations.

Materials and Methods:

This study was conducted in a 2800 sow herd located in Toledo, Spain. The herd is positive for PRRS, M. hyo. Pigs are vaccinated with CircoFLEX® weekly at 3 weeks of age. PCV2 was detected in 4 week old piglets showing performance problems during nursery phase although the sow herd didn´t have reproductive performance problems.

To evaluate the stability of the herd to PCV2, we bled 39 presuckle piglets and individually qPCRs were run following this protocol:

- 3 piglets per litter from 5 parity 1-2 sows(P1-2)

- 3 piglets per litter from 4 parity 3-4 sows(P3-4)

- 3 piglets per litter from 4 parity ≥ 5 sows.(> P5)

The same sampling was repeated 2 months after mass vaccination of the whole sow herd with Ingelvac CircoFLEX®(1ml).Another mass vaccination was applied due to high pressure of the virus.The third sampling was done 2 months after the second vaccination. All statistical analyses were performed using SPSS v.15 (SPSS Inc. Chicago, IL, USA). Differences were considered statistically significant at p< 0.05.

Results:

In the first sampling corresponding to piglets from non-vaccinated sows, PCV2 virus was detected in 66,7% of the piglets in P1-2,70% in P3-4 and 33,33% in > P5 and the mean of viral load(expressed as log10) was high showing 8.87 in P1-2, 7.13 in P3-4 and 5.66 in > p5. When looking at the different parity groups, after the first mass vaccination the results didn´t show any difference of PCV2 positive piglets but a strong reduction was observed in viral load (8,87 vs 3.74 in P1-2, 7.13 vs 4.73 in P3-4 and 5.66 vs 4.31 in> P5).None of the samples after the second mass vaccination resulted in positive sample, reducing the viral load below the detection level.

Conclusion:

According to the results obtained by qPCRs, we can conclude that is possible to reduce prevalence and viral load of PCV2 in presuckle piglets by using Ingelvac CircoFLEX® in a mass vaccination protocol in sows.

Further studies are necessary to determine whether there is a correlation between prevalence of PCV2 in presuckles pigs and performance parameters.

Disclosure of Interest: None Declared.

Published in the proceedings of the International Pig Veterinary Society Congress – IPVS2016. For information on the event, past and future editions, check out https://www.theipvs.com/future-congresses/.