Since its initial detection in May 2013, PEDv has spread rapidly throughout the US swine industry, with 6317 cases being confirmed in 29 states by May of this year.
This study, funded by Kemin and published in peer-reviewed BMC Veterinary Research,was led by Dr Scott Dee, director of research at the Minnesota-based Pipestone Veterinary Services. The authors say their findings indicate that it may be possible to protect feed against the deadly PED virus.
Rationale for the study
Dr Dee and his team, in another piece of research published in August, confirmed that contaminated feed could be a vehicle for PEDv infection of naïve piglets.
"As this new information confirmed feed as a risk factor, it became imperative to seek solutions," they said.
Thus, this follow up study was conducted to evaluate whether a liquid antimicrobial product containing formaldehyde and organic acid could mitigate said risk.
"The rationale for this approach was based on previous publications indicating that products containing formaldehyde and organic acids have a positive effect on Salmonella reduction in feed.
Furthermore, additional studies have demonstrated that formaldehyde treatment of organ inoculums containing Turkey Coronavirus (TCoV) rendered this material non-pathogenic, whereas other treatments failed to ameliorate its negative effects.
As PEDV and TCoV are both Coronaviruses, it was hypothesized that formaldehyde treatment of PEDV-contaminated feed may induce an anti-viral effect and prevent infection of susceptible pigs," said the Pipestone team.
Sal CURB, developed by the Des Moines headquartered, Kemin, is a US Food and Drug Administration (FDA) approved liquid antimicrobial used to control Salmonella contamination in poultry and swine diets.
The Pipestone researchers said they tested three groups of pigs over 14 days. One group of piglets was given feed spiked with PEDv; another group was given the same feed treated with Kemin's product, Sal CURB; and a third group was given PEDv-free feed.
The pigs receiving the feed with the Kemin product and the PEDv-free feed showed no evidence of infection, said the authors.
However, the animals given the virus-spiked feed showed clinical signs of PEDv infection such as vomiting and diarrhea and viral shedding in feces two to three days post-consumption of non-treated feed, they said.
"An acknowledged limitation was that the results are based on very small populations of pigs housed under experimental conditions and cannot be extrapolated to today’s large-scale commercial farm conditions until further testing can be conducted," said Dee and his team.
In addition, the study was not designed to answer questions which still remain regarding the liquid antimicrobial product, such as the duration of activity against PEDv, its effects on other viral pathogens, its effect on dietary nutrients and the logistics of application and daily use, they added.
However, the authors, say that "this is the first publication providing evidence that a means to ‘biosecure’ feed against a globally significant virus may be possible."
OIE issues findings into pig blood products' link to PEDv
Meanwhile, today the World Organization for Animal Health (OIE) confirmed that, contrary to earlier reports, pig blood products such as dried plasma are not a likely source of infectious porcine epidemic diarrhoea virus (PEDv) provided that good manufacturing practices and biosecurity standards are followed.
It said the findings followed scientific work conducted by an OIE ad hoc group on PEDv, to which a group led by the International Feed Industry Federation (IFIF) composed of experts from the affected regions, as well as from the blood plasma industry, contributed relevant scientific information and data.
Alexandra de Athayde, IFIF executive director, said “not only is this an important finding for the feed chain highlighting our strong commitment to feed safety, but it also demonstrates the importance and benefits of cooperation between IFIF and OIE, in particular with regards to the prevention and management of infectious diseases.”
Source: BMC Veterinary Research 2014,
Published online ahead of print: doi: 10.1186/s12917-014-0220-9
Title: An evaluation of a liquid antimicrobial (Sal CURB) for reducing the risk of porcine epidemic diarrhea virus infection of naïve pigs during consumption of contaminated feed
Authors: S. Dee, C. Neill, T. Clement, J. Christopher-Hennings, E. Nelson