Friends, relatives and Ulster Rugby stars past and present were among the mourners who gathered at Ballynahinch Baptist Church for the funerals of the father and sons on Wednesday.
Those who came to pay their respects to the Spence family filled the church and gathered outside the building to hear the service.
Emma Spence, who pulled her 58-year-old father from the slurry tank, and tried to rescue Graham, 30, and 22-year-old Ulster player Nevin, was admitted to hospital after Saturday's accident.
She was accompanied by her sister Laura, their mother Essie and Graham's wife Andrea at the funeral service, where she paid an emotional tribute to the men.
"Dad. He was the one you probably saw taking up half the Drumlough Road with the tractor.
"He is the one that greeted you with a thump on the arm. He is the one who christened you with a new nickname no matter who you were.
"To me he was the one sitting at the kitchen table with his coffee made in only mum's best china cup listening to my every worry and telling me the truth whether I wanted to hear it or not," she said.
They were gentlemen, hardworking men, they were not perfect, but they were genuine. They were best friends. They were just ordinary - but God made them extraordinary.
Emma Spence
Graham, a father of two, she said was "driven by the thought of improving farming" and was "unashamedly Nevin's biggest fan...a gentle giant [who] doted on his two children".
"He is the one who came alive when he talked about farming.
"To me he is the one who protected me as I grew up. To me he is looking at me when I look at Nathan and I look at Georgia."
Miss Spence also spoke of her younger brother, 'Wee Nev', the rising Ulster star who could have played for Ireland and was given the nickname 'Superstar' in jest.
"He is the one who did not love the limelight but handled it like a pro," she said.
"To me he is the baby. To me he is the one mum had the organic blueberries and prize-winning steak ready for when he called."
Members of the Ulster Rugby team carried Nevin's shirt-draped coffin into and out of the church.
Andrew Trimble, Chris Henry, Paul Marshall and Luke Marshall joined former teammates Willie Faloon and Ian Whitten for the task. Injury prevented Paddy McAllister - one of Spence's closest friends in the Ulster set-up - from taking his place as a pall-bearer.
Coach Mark Anscombe and director of rugby David Humphries joined star players Rory Best, Stephen Ferris, Paddy Wallace, Johann Muller in attending the service, along with players from Ballynahinch Rugby Club and other Irish provinces.
Current Irish coaches Eddie O'Sullivan and Declan Kidney and notable figures, including Tyrone GAA boss Mickey Harte, also attended.
Pastor Rodney Stout said the men had left a "positive legacy", but added that Mr Spence would be "horrified at the thought of the attention that he and his family have attracted".
Ulster Unionist leader Mike Nesbitt, SDLP leader Alasdair McDonnell, Sinn Féin Agriculture Minister Michelle O'Neill and DUP ministers Arlene Foster and Edwin Poots - a close family friend - all attended the funeral service, as did pupils from both Dromore and Wallace High, where Nevin and Graham went to school.
Thousands of tributes have already been left for the Spence family, including in a book of condolences at Ravenhill Rugby ground.