The man's wife was then attacked by the deer when she rushed to his aid.
The deer was euthanised by police at the scene.
She is said to be a passionate gardener and has owned a nursery in Wangaratta for three years, after taking over the 20-year-old business from her father.
Paul and Mandi McDonald, 45, were at their Moyhu farm, about 260km from Melbourne, on Wednesday morning when the tragedy occurred.
According to police the Waipiti deer - a cross between a red deer and an elk - had been a pet of the family for about 2 years.
Local resident Patrice Larkin said she knew the couple well.
$1 billion raised to rebuild Paris' Notre Dame after fire
According to cathedral guides, the rooster had acted as "spiritual lightening rod" to protect the Notre Dame faithful. A 100m crane lowered the copper statues representing the 12 apostles and four evangelists onto a lorry.
"The deer was shot a couple of times for the safety of the male and female", Acting Senior Sargent Purcell said.
"It's a very, very short sharp season where they get aggressive and fight with each other", said David Voss from Australian Deer Association, a hunters' lobby group.
He added that it's not unheard of for a deer to fatally attack humans in a domesticated scenario, adding: "Deers stop eating, they shed a huge percentage of their body weight".
Australian Deer Association's Barry Howlett told the Herald Sun it's now mating season for deer and many will become aggressive and territorial.
A man has been killed by a near on a property in Victoria.
A recent study into all deaths caused by animals in Australia between 2000 and 2013 found none had involved deer. The Parks Department has proposed funding a bigger hunt to control the growing number of feral deer throughout Victoria.