2023-08-01 12:04:53
A major setback for poultry farmers who let their chickens run outside. Barely three weeks following the national confinement obligation was lifted due to bird flu, the virus once once more entered a poultry farm. Last week, the first stable infection since January was detected at an organic laying hen farm in Biddinghuizen (Flevoland). The 11,000 chickens have now been killed and a transport ban applies in the zone around the company. There will be no further changes to the (abolished) confinement obligation. Since July 6, this only applies in the Gelderse Vallei and De Peel, the areas in the Netherlands with the highest poultry density.
At the affected farm, the animals were indeed able to go outside once more. “The chance of infection is greatest at farms with outdoor areas and the presence of waterfowl is also a risk factor,” outlines epidemiologist Armin Elbers of Wageningen University & Research (WUR). There are plenty of seagulls and geese in the wet Flevopolder, for example. “I am therefore not surprised that there is another infection: following all, the virus is still circulating among wild birds.”
Calculated risk
Agriculture minister Piet Adema (CU) actually took a conscious risk by lifting the confinement obligation at the beginning of this month. The agricultural sector has been urging the lifting of the confinement obligation for some time now. After all, poultry farmers who have invested in animal welfare are the victims of the measure. They are no longer allowed to sell their eggs as free-range eggs if the animals are not allowed to go outside.
In the case of important bird flu decisions, the minister usually asks the Animal Diseases Expert Group for advice. In his latest advice, he noted that the risk of infection on poultry farms has decreased in recent months. From ‘medium’ (in the Southeast Netherlands) or ‘high’ (in the Northwest Netherlands) to ‘medium-low’ for the whole country.
This is because it has been quiet at companies for months. Not only in the Netherlands, but also in neighboring countries where, in some cases, the confinement obligation no longer applied. If the chickens were allowed to go outside once more in the Netherlands, the risk level would rise to ‘medium with a high degree of uncertainty’. Because chickens that walk outside are more likely to come into contact with infected gulls, for example, according to the advice. And it is precisely among black-headed gulls that bird flu is currently making quite a house.
Lasers with green light
Researchers from WUR and Utrecht University have been testing an avian flu vaccine for some time now. In a small-scale laboratory test, two vaccines proved to protect well once morest disease: the vaccinated chicks did not become ill when they were exposed to the virus.
Since then, we have been waiting for a practical test at an existing company. That test has to do with all kinds of regulations – for example, can the eggs be sold as long as the vaccine has not yet been officially registered? – quite a few feet in the earth. A trial will start this autumn, coincidentally also at a company in Biddinghuizen.
It will then take at least a year before the results are known. And probably even longer until the vaccine can be deployed on a large scale. Nevertheless, there are possibilities to reduce the risk of infection even without a vaccine, Elbers emphasizes. Hygiene around the stable is always an important point of attention. And he himself previously conducted research into a laser method that deters wild birds.
“In addition, at night – when the chickens are indoors – we shine an automated green laser into the outdoor area,” he explains. “That frightens the wild waterfowl when they look for food in the enclosure.” It prevents contaminated bird droppings from ending up in the free range for chickens. “And during the day, the laser focuses precisely on the meadows around the company, so that grazing geese do not come close. At the company where we tested, there was an avian flu infection almost every year. Now there has been no outbreak for a few years, while many other companies in the area are affected.”
Read also:
Two bird flu vaccines seem effective; government wants to continue with research
In a first, small-scale test, two bird flu vaccines appear to work very well: none of the vaccinated chickens became ill. A larger-scale test at a poultry farm will now follow.
1690946420
#minister #deliberately #risk