[PeterPrinciple]

Microneedle patch tattoos can also be used to encode information in the skin of animals. Rather than clipping the ear or applying an ear tag to animals to indicate sterilization status,

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Because the ability to differentiate between bulls and steers has been lost....................

[Zuriel]

The inside of an ear is where my dad and I would tattoo purebred angus heifers and bulls. We kept records of the breeding stock. We ear tagged as well, but once in a while one would manage to lose it.