Second PCV2 Vaccination Brings Benefits in PRRS-Challenged Pigs

Despite the decrease in performance related to the second vaccination of porcine circovirus type 2 (PCV2), the second vaccination improved final performance and decreased the number of removals due to the health challenge from porcine respiratory and reproductive syndrome (PRRS), concluded N.W. Shelton at the Kansas Swine Day 2009.

23 February 2010

4 minute read

A total of 2,571 barrows and gilts (PIC 337 × 1050) were used to determine the effects of porcine circovirus type 2 vaccine (PCV2) on nursery and finishing pigs that were challenged with porcine respiratory and reproductive syndrome (PRRS), explained N.W. Shelton.

Treatments were arranged in a 2×2 factorial design with main effects of gender (barrow or gilt) and vaccine (PCV2 vaccinates or non-vaccinates). Vaccinated pens received two doses of commercial PCV2 vaccine (Circumvent PCV from Intervet Inc., Millsboro, Delaware) according to label directions on days 1 and 22 in the nursery. All pigs were also inoculated on day 30 with serum containing PRRS virus as part of this production system's protocol. Barns were double-stocked from days 0 to 51. On day 51, gilts were moved to an adjacent facility and barrows were split into two pens.

In the period after the initial PCV2 vaccination (days 0 to 15), no differences in average daily gain, average daily feed intake or feed to gain were observed (P>0.13) between genders or between vaccinates and non-vaccinates.

However, in the period after the second PCV2 vaccination (days 15 to 29), vaccinated pigs had a lower (P<0.02) average daily gain than unvaccinated pigs as a result of decreased (P<0.04) average daily feed intake. Gilts also had higher (P<0.04) average daily gain and average daily feed intake than barrows.

In the period after all pigs were inoculated with PRRS virus (days 29 to 50), those vaccinated against PCV2 had improved (P<0.001) feed conversion compared with unvaccinated pigs, and a trend (P<0.08) for improved average daily gain. Gilts had poorer (P<0.01) feed conversion than barrows from days 29 to 50.

Over the entire 50-day nursery portion of the study, no differences were observed (P>0.61) for average daily gain, average daily feed intake or final weight between genders or the vaccinated and unvaccinated groups. However, feed conversion was improved (P<0.001) with PCV2 vaccination.

Pig weights on days 71 and 99 were increased (P<0.001) in vaccinated pigs compared to the unvaccinated animals, and barrows were heavier (P<0.001) than gilts on day 99.

At the conclusion of the study (day 132 for barrows and day 142 for gilts), the percentage of pigs remaining on test was lower (P<0.001) in non-vaccinated pens than vaccinated pens (70.2 per cent versus 94.7 per cent, respectively).

This study suggests that despite the decrease in performance related to the second vaccination of PCV2, the second vaccination improved final performance and decreased the number of removals due to the PRRS health challenge, concluded Shelton and co-authors.

Reference

Shelton, N.W., M.D. Tokach, S.S. Dritz, R.D. Goodband, J.L. Nelssen, J.M. DeRouchey and J.L. Usry. 2009. Effects of porcine circovirus type 2 vaccination on nursery and finishing pig performance under a PRRS Challenge. Proceedings of the Kansas Swine Day 2009, 28-32.