by
Antinox
Viral diseases can devastate flocks and cause huge losses in productivity
Control relies on a combination of robust biosecurity to reduce the presence of disease vectors in the poultry shed and vaccinations so the bird itself remains healthy.
Vaccination may appear a straightforward solution but there are drawbacks. For particular viruses, use of vaccinations can result in import restrictions for poultry meat and eggs so producers are reluctant to vaccinate except in emergencies.
This is the case for avian influenza and exotic Newcastle disease so to control
these diseases producers focus on tight biosecurity to reduce the flock’s
exposure to vectors.
Disease vectors are most commonly the faeces or body fluids from infected birds. Contamination can be direct, with the carrier breaching wild bird biosecurity measures at production facilities, or indirect, with the virus having been transferred to other mechanical vectors such as humans, vehicles, vermin or insects which then go on to breach biosecurity measures and access production flocks.
Dr Kurt Richardson, Chief Science Officer at Anitox, believes the poultry industry needs to wake up to the risk of feed as one such vector for viruses.
“There is certainly a lot more we need to learn about virus transmission in feed, particularly with respect to avian influenza which is one of the biggest challenges the global poultry industry faces.”
“But if we look at the evidence, we have examples of transmission of several viruses through feed in poultry and in pigs. Plus, there are quite a lot of unresolved questions that point towards contaminated feed as a cause of infection.”
Before looking in more detail at the unknowns, it is important map out what we know about virus transmission in feed.
Feed was shown to be a vector thirty years ago following an outbreak of Newcastle disease in England.
Feed ingredients were heavily contaminated with pigeon faeces. As a result, the mill produced contaminated feed, which caused disease on poultry farms.
Investigations found the virus in pigeons and isolated it from the feed that confirmed the vector pathway.
“Newcastle disease showed that one virus could be transmitted from feed which raised the distinct possibility that other viruses would spread this way too,” says Dr Richardson, “10 years later, an outbreak of Infectious Bursal Disease (IBD) in Denmark was linked to a specific feed mill although the virus was not isolated from the feed or any other possible vector.”
“This case showed an association with feed but wasn’t definitive; however, it introduced doubt into another area. The infection was linked to pelleted feed, by Dutch law it was supposed to be pelleted at 81–86C for 2.5 minutes, conditions believed to be sufficient to inactivate the virus for IBD but this has never been proven.”
Read the full article, HERE.
Viral diseases can devastate flocks and cause huge losses in productivity
Control relies on a combination of robust biosecurity to reduce the presence of disease vectors in the poultry shed and vaccinations so the bird itself remains healthy.
Vaccination may appear a straightforward solution but there are drawbacks. For particular viruses, use of vaccinations can result in import restrictions for poultry meat and eggs so producers are reluctant to vaccinate except in emergencies.
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| Image credit: Vicky Hall on Flickr (CC BY-SA 2.0) |
Disease vectors are most commonly the faeces or body fluids from infected birds. Contamination can be direct, with the carrier breaching wild bird biosecurity measures at production facilities, or indirect, with the virus having been transferred to other mechanical vectors such as humans, vehicles, vermin or insects which then go on to breach biosecurity measures and access production flocks.
Dr Kurt Richardson, Chief Science Officer at Anitox, believes the poultry industry needs to wake up to the risk of feed as one such vector for viruses.
“There is certainly a lot more we need to learn about virus transmission in feed, particularly with respect to avian influenza which is one of the biggest challenges the global poultry industry faces.”
“But if we look at the evidence, we have examples of transmission of several viruses through feed in poultry and in pigs. Plus, there are quite a lot of unresolved questions that point towards contaminated feed as a cause of infection.”
Before looking in more detail at the unknowns, it is important map out what we know about virus transmission in feed.
Feed was shown to be a vector thirty years ago following an outbreak of Newcastle disease in England.
Feed ingredients were heavily contaminated with pigeon faeces. As a result, the mill produced contaminated feed, which caused disease on poultry farms.
Investigations found the virus in pigeons and isolated it from the feed that confirmed the vector pathway.
“Newcastle disease showed that one virus could be transmitted from feed which raised the distinct possibility that other viruses would spread this way too,” says Dr Richardson, “10 years later, an outbreak of Infectious Bursal Disease (IBD) in Denmark was linked to a specific feed mill although the virus was not isolated from the feed or any other possible vector.”
“This case showed an association with feed but wasn’t definitive; however, it introduced doubt into another area. The infection was linked to pelleted feed, by Dutch law it was supposed to be pelleted at 81–86C for 2.5 minutes, conditions believed to be sufficient to inactivate the virus for IBD but this has never been proven.”
Read the full article, HERE.
The Global Miller
This blog is maintained by The Global Miller staff and is supported by the magazine Milling and Grain
which is published by Perendale Publishers Limited.
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