National Animal Identification System.
Some years ago, it was an idea of the United States Government for identifying and keeping track of all livestock-type animals. They hoped to be able to track animal diseases, by tracking which animals were where and had been in contact with which other animals.
The plan was to make it mandatory for the entire country. That would have meant every chicken and every other livestock animal getting an id chip, every owner registering their property information with the government, and every owner filling out forms every time an animal was bought, sold, butchered, or taken off the property for any reason.
There were some exceptions to make it easier for large groups, such as filling out a single form when transporting or butchering an entire herd of cattle or flock of chickens, instead of a separate form for each individual animal in that herd or flock.
Many chicken keepers opposed it, and so did many other people who had just a few animals. I don't know what the big commercial farmers thought about it.
I haven't heard much about it in quite a few years. I know it did not become mandatory. I'm not sure whether it still exists as a voluntary program, or whether it was abandoned entirely.
If you want more information, this wikipedia article looks fairly good at present:
https://en.wikipedia.org/wiki/National_Animal_Identification_System
