Field Efficacy of a PCV2 Vaccine in a High-health Danish Farm Under Subclinical PCVD Conditions10 July 2015
PCV2 is a widespread virus, present in the swine population all over the world. Even in subclinical conditions, it has been proven to decrease pig performance in the whole production cycle, hence decreasing profitability, writes P.Mortensen et al, Merial.
The objective of this trial was to demonstrate that PCV2 piglet vaccination can improve weaning-to-slaughter performance in a high-health status and high-performing farm under subclinical PCVD field conditions in Denmark.
Materials and Methods
The trial was conducted on a well managed danish wean-to-slaughter pig farm producing 22,000 pigs per year with no PCVD clinical signs and good production data.
The farm was classified SPF Myco. hyo.-positive. Prior to the trial, a serological survey was performed by collecting three time five blood samples at 12, 16 and 20 weeks of age.
The sera were pooled and assayed for PCV2 DNA using a qPCR technique.
Five weekly batches of piglets received over a two month period were included in the study.
The first group was left as an unvaccinated control whereas the other four groups were vaccinated against PCV2 at arrival at the wean-to-finish farm in their fourth week of life with 0.5ml, IM in the neck.
Group based weights at arrival and individual carcass weights were recorded. Live weights at slaughter were calculated based on a 76.3 per cent live weight-carcass weight ratio.
Statistical analyses were performed using non-parametric tests.
The three pools of blood samples all demonstrated positive with log10 pCV2 DNA copy values: 3.84, 5.92 and 6.76 confirming subclinical PCV2 circulation on the trial farm.
In this trial, including 2.063 pigs at slaughter, an improvement of growth was observed in each batch of PCV2-vaccinated pigs as compared to unvaccinated pigs: ADWG and days to market were highly-significantly (p<0.01) improved by resp .34 g/day (24 to 42 g/day) and 5.3 days (4.2 to 6.3 days).
The carcasses were numerically heavier in all vaccinated groups as compared to the unvaccinated group except in one batch displaying a non-significant difference (p=0.24) of 0.21 kg.
From the farm production data recordings, mortality dropped from 1.7 per cent to 0.8 per cent from weaning to 30kg and from 2.5-2.0 per cent to 1.5-1.0 per cent from 30kg to slaughter following the implementation of the PCV2 vaccination.
The number of treated pigs on the farm was reduced. The health remarks recorded at the slaughterhouses was also reduced.
Discussion and Conclusion
These results demonstrated the presence of subclinical PCVD, even in a well managed farm.
In this context, the initiation of a PCV2 piglet vaccination programme successfully improved production performance of this high-health and high-performing Danish herd.
Presented at the 2015 European Symposium of Porcine Health Management