Keeping tabs on ol' Bessie the cow got a little bit easier with the advent of electronic ear tags. Equipped with radio frequency identification (RFID) chips, the tags can communicate with antennas placed on feeding troughs so that farmers know when – and how much – each of their cattle is eating. Changes in eating patterns are often a sign that something is wrong with a cow [source: Coxworth].
Similarly, some cows have pedometers on their ankles to tip farmers off as to how much time they spend lounging or standing still, which – in addition to potentially being a sign that a cow is in heat – can also indicate health issues. Identifying and isolating problems like foot-and-mouth or mad cow disease can mean the difference between losing one cow and losing a whole herd of cattle [source: Coxworth].