why is cows milk affected by bird flu?
In: Biology
Bird flu, or avian influenza, primarily affects birds. However, in some cases, it can disrupt other species as well. Now, cows themselves don’t get bird flu, so the milk straight from the cow isn’t directly affected by the virus.
The real impact comes from how bird flu can shake up the farming world. If there’s an outbreak, it might lead to restrictions on farm movements to stop the virus from spreading. This can mean fewer workers to help milk the cows or transport the milk, and sometimes even farms close to an outbreak might even be temporarily shut down to keep things safe. All this chaos can mess with the amount of milk getting to stores and might even make it more expensive.
So, while the bird flu doesn’t taint the milk directly, it can make it a bit of a headache to get it from the farm to your fridge!
Milk is blood with extra steps. That is to say, everything in milk originally came from the blood circulating in the cow. The presence of a viral RNA in something’s milk means the mammal is harbouring that virus.
It is worth knowing that viruses are detected via looking for their RNA. RNA present in milk does not mean the virus is present and active in pasteurised milk.
Cows, being mammals, are not very similar to birds. This indicates that the influenza strain in birds has aquired a mutation that allows it to infect mammals. We have now seen that this strain can pass from cow-to-cow and can be found in cow’s lungs, so it is no longer simply transmitted via bird-to-cow route.
Bird flu can jump species. We’re having an outbreak that mostly hits water fowl but also raccoons. It’s why the combination of pigs, poultry and humans can make for wild flu variants as they get handed from species to species and mutate along the way.
The current problem with cows/cattle in the US is the gross practice of feeding used poultry litter to them. Broiler chicken are kept in large halls. Some stables can hold 50.000 chicken at once. The chicken are kept on the same litter all their (short) lives, and spill feed into it. Why waste chicken feed when you can feed it to cows, along with 40days worth of chicken shit (and the occasional dead bird).
Flu viruses don’t survive long outside their hosts and chicken die like flies when they catch it. So the poultry litter is not sooooo terribly contaminated, but that’s the best guess what’s the source of the problem, because it doesn’t happen elsewhere with saner regulations.
Latest Answers