If you've ever gone hiking through a farmer's field, you've likely noticed that your compass points directly to the nearest cow.
This is not an accident, and is part of a government conspiracy to replace all livestock with robots, in order to make them more accessible to aliens beaming them up from orbit[0].
This slow transition from biological to mechanical cows is known as hardware disease[1], and should be celebrated.
The more you know.
0: https://www.aemagnets.com/news/how-cow-magnets-save-animals.html
1: https://en.wikipedia.org/wiki/Hardware_disease
I already know nobody is going to click on OP's link, so the short version is the magnet is permanently placed down in the cow's second stomach and it stays there for life, and if the cow eats and nails or pieces of barbed wire or other metal bits found on farms, it sticks to the magnet instead of shredding up their intestines or other stomachs as their feed is tossed around and digested and re-chewed and digested again, etc.
Some models have plastic caging around the magnet to also protect the cow's stomach from sharp metal things stuck to the magnet.
Thats actually fascinating.
Wait until you learn about portholes to their stomachs and methane vents people install on cows.
Watch "All watched over by machines of loving grace" BBC, Curtis; might be also on some dread YouTube. The cow portholes were part of (unexpected) scientific disproof of the trite popular wisdom of "Ballance of Nature." Whole series is a trip, if maybe a bad one.
I liked that band