Background & Objectives
Porcine Circovirus type 2 (PCV2) is a ubiquitous virus that can lead to significant production losses in all of its clinical manifestations: PCV2 systemic disease (PCV2-SD), PCV2 reproductive disease (PCV2-RD), porcine dermatitis and nephropathy syndrome (PDNS)
and subclinical infection1. So that control of PCV2 virus infection is essential for swine herds worldwide.

The aim of this study was to compare the impact of two PCV2
vaccines on production parameters of a high health farm which was positive for PCV2 in Canada.

Materials & Methods
A 600-sow farrow-to-wean farm in Canada was selected, and piglets from this farm were monitored through the finishing period until slaughter. This farm is considered to have a high health status (Mycoplasma hyopneumoniae (Mhyo) negative and Porcine Respiratory Reproductive Syndrome (PRRS) negative), confirmed by routine diagnostics, and a high standard of animal welfare according to Canadian standards. The farm was positive for PCV2, genotypes b and d.

Two consecutive pig batches were divided into two groups. In the first batch, one group (n=843) was vaccinated with MHYOSPHERE® PCV ID (MH), an intradermal needle-free vaccine against Mhyo and PCV2-associated disease, with HIPRADERMIC® (intradermal needle free device) at 4 weeks of age. The second group (n=886) was vaccinated with two doses of Vaccine A, an intramuscular vaccine against PCV2 at 4 days and 4 weeks of age. In the second batch, the same methodology was followed with 830 pigs in the MH group, and 830 pigs in Vaccine A group. The production parameters measured included the slaughter weight, days in the fattening unit, growth performance, mortality, and antibiotic treatments. Statistical analysis was conducted for all different parameters.

No significant differences (p>0.05) were observed in body weight between groups at the time of vaccination. However, significant differences (p<0.001) were observed in the slaughter weight with the MH group (128.23±11.35Kg) vs Vaccine A (127.26±11.5Kg), so the carcasses of pigs that were vaccinated with MH weighed 0.97 Kg more than Vaccine A pigs at slaughter. Also, the pigs in the MH group were slaughtered 1.38 days earlier (p=0.008) compared to the Vaccine A pigs.

Consequently, the average daily weight gain (ADWG) was significantly higher in the MH group, with an increase of 18 g/day (p<0.001). Regarding mortality (from weaning to the end of the fa-ttening period), the MH group had 4.42% and the Vaccine A group 4.2 % with no statistically significant differences. Antibiotic treatments were also similar in both groups with no statistically significant differences.

Discussion & Conclusion

These results indicate that intradermal needle-free vaccination with MHYOSPHERE® PCV ID applied with HIPRADERMIC® performed better than Vaccine A on this farm in terms of growth performance, and consequently with higher weight at slaughter and fewer days at the fattening unit. As this farm was negative for Mhyo and PPRS, and no other changes were made, this could be attribu- ted to the vaccine itself but could also be a result of the welfare2 and health benefits of needle- free vaccination that have been re- ported in previous studies. Some of these benefits are avoidance of iatrogenic dissemination that can happen with needle devices3 and higher growth performance during the first weeks after weaning4 with no systemic adverse reactions.

1. Segalés, J. et al. Disease of Swine Eleventh Edition (2019), 473-487.
2. Dalmau A, et al. Intramuscular vs. Intradermic Needle-Free Vaccination in Piglets: Relevance for Animal Welfare Based on an Aversion Lear- ning Test and Vocalizations. Front Vet Sci. 2021 Aug 11;8:715260. doi: 10.3389/fvets.2021.715260. PMID: 34458358; PMCID: PMC8385536.
3. Dachrit, N. et al. Evaluation of PPRS and ASF virus dissemination between pigs when using conventional needle and needle free-device, ESPHM 2021 (Bern)
4. Puig A. et al. Comparison of effects of a single dose of MHYOSPHERE® PCV ID with three commercial porcine vaccine associations against My- coplasma hyopneumoniae (Mhyo) and porcine circovirus type 2 (PCV2) on piglet growth during the nursery period under field conditions. Vet Res Commun. 2022 Dec;46(4):1167-1173. doi: 10.1007/s11259-022- 09971-y. Epub 2022 Jul 13. PMID: 35829861; PMCID: PMC9684222.

Code assign: BBD-PP-74