Field evaluation of a ready-to-use combined Porcine circovirus type 2 and Mycoplasma hyopneumoniae vaccine in Denmark – a historical comparison of productivity parameters in 20 nursery and 23 finishing herds

Abstract

BackgroundIn practice, field evaluation of vaccine efficacy in individual herds is often based on a historical comparison of productivity data following initiation of vaccination. Being biased by time, this study design highly contrasts the more controlled, parallel-group design used for most initial vaccine efficacy studies but offers the possibility of including a larger number of animals and herds. As an important add-on to previous findings in controlled studies, the objective of this study was to evaluate the field efficacy of the ready-to-use combination vaccine Porcilis® PCV M Hyo (MSD Animal Health) by an observational historical study design using routinely generated herd productivity data.ResultsData on mortality, average daily weight gain and feed conversion rate were collected as yearly averages for one year prior to and one year after implementation of Porcilis® PCV M Hyo vaccination from 20 nursery and 23 finishing herds. When comparing pre- and post-vaccination periods, the average improvements in productivity data amounted to − 0.4 percentage points for mortality (p = 0.014), + 5 g for average daily weight gain (p = 0.555) and − 0.06 feeding units(FU)/kg for feed conversion rate (p = 0.074) in nursery herds and − 0.5 percentage points for mortality (p = 0.012), + 34 g for average daily weight gain (p < 0.001) and − 0.04 FU/kg for feed conversion rate (p = 0.133) in finishing herds. Even though some nursery and finishing herds also previously vaccinated against PCV2 and/or Mycoplasma hyopneumoniae, this did not significantly affect the results. For finishers, these results were obtained when difference in arrival weights between the periods and shared ownership of the herds were additionally taken into account.ConclusionIn these 20 nursery and 23 finishing herds, previous findings from parallel-group vaccination studies concerning average daily weight gain for finishers were confirmed. Additionally, a significant effect on mortality for both nursery and finishing herds was demonstrated in this evaluation based on routinely generated herd productivity data.Electronic supplementary materialThe online version of this article (10.1186/s40813-018-0104-7) contains supplementary material, which is available to authorized users.

Efficacy Studies against PCV-2 of a New Trivalent Vaccine including PCV-2a and PCV-2b Genotypes and Mycoplasma hyopneumoniae When Administered at 3 Weeks of Age

“…However, our and these mentioned results contrasted with other studies where a significantly lower mortality was observed in vaccinated animals [48,53] compared to non-vaccinated ones. It is noteworthy that the present field studies were designed with vaccinated and non-vaccinated commingled within the same pens, so, globally, vaccinated pig benefits could be worsened and nonvaccinated detriments could be ameliorated due to an overall increase of infectious pressure for vaccinated animals and a lower one for non-vaccinated ones [53].…”

Efficacy Studies of a Trivalent Vaccine Containing PCV-2a, PCV-2b Genotypes and Mycoplasma hyopneumoniae When Administered at 3 Days of Age and 3 Weeks Later against Porcine Circovirus 2 (PCV-2) Infection

“…This could be related to the fact that the V group and NV group animals were comingled in the same pen/room. In such a scenario (not frequent under field conditions), the infectious pressure of non-vaccinated piglets may have hindered the vaccine efficacy [47].…”