The bull had been known to attack people in the past.
"This particular bull has done this before to another man."
He said the rescue helicopter was called to up to three incidents in cattle yards each year.
A hospital spokesman said the man was discharged yesterday afternoon. He declined to speak to Hawke's Bay Today.
St John Heretaunga territory manager Brendon Hutchinson described the incident as "reasonably minor" and said the man was in a stable condition while being airlifted.
Federated Farmers Hawke's Bay president Will Foley said farmers should always be alert when handling cattle.
"It's definitely always a risk handling cattle in cattle yards," he said.
"Farmers always have to be very wary of animals being unpredictable in the yard, particularly if they're on their own.
"Always keep your distance and try not to provoke them."
A Flag Range Rd resident said she noticed an ambulance go by in the morning but she was not aware of the incident.
In August 2013 Clifton farmer Angus Gordon was hammered to the ground twice by a charging cow, resulting in him dislocating both shoulders.
Then in February 2014 a 23-year-old Norsewood man broke his leg after a cattle beast knocked him from his motorbike.
