"It's been a fantastic day. I'd really like to thank my wife for motivating me to study in the lead-up to the event."
The prestigious contest has undergone a major overhaul since marking its 50th anniversary in Invercargill last year.
"We're now showcasing all aspects of what it means to be a modern food producer," host Te Radar told the 170-strong crowd at the Milton Coronation Hall.
In a butchery challenge, contestants had to create a rack of lamb, photograph it for a magazine, and then develop an international marketing pitch for the meat.
McRae's win netted him $12,000 worth of prizes, including an XR150 Honda farm bike.
He also picked up awards for showcasing food production and championing environmental best practice.
Prior to moving home to the family farm, McRae spent three years working as a banker.
The Wyndham Young Farmers member has a Bachelor of Commerce (Agriculture) from Lincoln University.
Listen to Te Radar talk to The Country about the Otago/Southland regional Young Farmer final below:
Roxburgh sheep and beef farmer Tom Blackmore, 24, came second.
Luke Templeton, 30, who 50:50 sharemilks 600 cows at Riverton, placed third and took out the innovation award.
James Robson won the prize for outstanding leadership and Allen Gregory was named the most tech-savvy contestant.
McRae's win has secured him a spot in the FMG Young Farmer of the Year Grand Final in Hawke's Bay in July.
The Young Farmer of the Year is an iconic contest which began in 1969 and showcases the country's agri-food sector.
The contest is supported by FMG, Ravensdown, Honda, WorkSafe, Zero Harm Farm, STIHL, Lincoln University, Southfuels, Northfuels, Betacraft and New Holland.