The horse's deeds were reported in The Scotsman newspaper.
The farmer, Fiona Boyd, 40, was reportedly attempting to reunite a cow with its calf in a herd.
The Scotsman reported that the cow attacked when it sighted its calf just as Mrs Boyd approached the young animal.
The cow knocked her to the ground and then put its full weight on top of her.
Mrs Boyd's 15-year-old chestnut mare came to her aid, kicking at the cow to make it move. She was able to crawl safety while the mare continued kicking out at the cow.
Mrs Boyd was treated at hospital for bad cuts and bruising.