Kent Lehs, a manager with the Midwest Dairy Association, which sponsors the display, said Friday it wasn't a question of Jackson's achievements that drew complaints.
"They were more pointed toward what they felt they understand Michael Jackson's reputation was and not as a singer and dancer, but more some of the things he was implicated on in his personal life," said Lehs.
Jackson was accused of molesting a child in 1993 and settled the case without a trial, and he was acquitted of child molestation charges in a separate case in 2003.
Butter sculptures have been popular part of the fair since 1911, and fairgoers jostle for position in front of the glass-enclosed displays to watch the artists at work. Besides a life-size Butter Cow, which always makes an appearance, sculptors usually whip up another display.
Past works have included statues of Elvis Presley and Tiger Woods, Harry Potter, a Harley Davidson motorcycle and even a slippery rendition of Leonardo da Vinci's "The Last Supper." And this year's display will celebrate the 40th anniversary of the moon landing.
Fair staff first announced plans for a Jackson sculpture days after his June 25 death. After being deluged with complaints, the staff clarified that the Jackson statue would be of him moonwalking, in keeping with the theme.
But the complaints kept coming, so organizers decided to put the issue to an online vote.
"They were not going to go to the fair or they were considering not going to the fair or to the (agriculture) building," Lehs said.
Fair spokeswoman Lori Chappell said more than 100,000 votes were cast and by a 65 percent to 35 percent margin, people rejected the Jackson sculpture. Voters were asked to include a ZIP code, and 97 percent of those submitted were from Iowa, she said.
"They've certainly shown a lot of passion for the fair over the past few weeks," Chappell said.
Sarah Pratt, the 155-year-old fair's fourth butter sculptor, is expected to begin her work later this month to be ready by the fair's Aug. 13 opening.