Republican Senate hopeful John Brunner has the backing of mainstream farming interests like the Missouri Soybean Association and John Deere & Co.

But four years ago, Brunner’s charitable foundation donated $10,000 to a group whose views on several big agricultural issues are at odds with some of the leading groups in the industry.

The Brunner Foundation, run by the former St. Louis home health care products executive and his wife, gave the money to the Humane Farming Association, a California-based farm animal safety group, according to federal tax records.

The association has strong concerns about the practices of large industrial farming, including the use by the meat industry of antibiotics for more than just therapeutic uses, and growth hormones. Generally speaking, agribusiness supports and promotes those practices.

“We support the use of antibiotics, according to guidelines provided with them,” said Estil Fretwell, a spokesman for the Missouri Farm Bureau.

Richard Oswald, president of the Missouri Farmers’ Union, which he said agrees with many of the Humane Farming Association’s policies, said, “Just from a general farming standpoint, (the association) wouldn’t appeal to mainstream agriculture in Missouri.”

In a statement issued today, Brunner said the decision to give the $10,000 to the Humane Farming Association was not his, but the choice of one of his three children.

““As a young child, my father taught me the value of charitable giving and I passed those same, important, values on to my children," Brunner said in the statement. "In that spirit, I set up the Brunner Foundation to encourage my children to become active in charity. I made it clear that each of them could give to the charity of their choice and that it would remain, solely, each child’s individual decision. In 2007, one of my children chose as a beneficiary the Humane Farming Association. I am extremely proud of my children, but, as with most families, I do not always agree with their choices or decisions.”

Brunner alleged that some groups “use deceptive rhetoric and tactics to deceive well-meaning people into supporting their far more dangerous agendas. But, let me be perfectly clear, I, personally, have never supported the Humane Farming Association.”

Brunner is one of the three leading Republicans seeking the party’s Senate nomination in the Aug. 7 primary. The others are former state Treasurer Sarah Steelman and Rep. Todd Akin. The winner will face Democratic Sen. Claire McCaskill in the general election.

Perhaps because a third of the state’s population lives in rural Missouri and in a close race, which the McCaskill contest is likely to be, every vote is crucial, Brunner appeared to double-down in trying to establish his political bona fides with the farm vote.

He let his rhetoric soar, accusing “extreme groups like the Humane Farming Association” of seeking to “end the agriculture industry in Missouri.”

Bradley Miller, director of the Humane Farming Association, said he was unaware of the donation from Brunner’s foundation, and seemed perplexed by his attack. He labeled them “broad brushes” and said the GOP candidate didn’t seem to be aware of what the group was about, which was not to kill off farming in Missouri.

“We receive contributions from all over the country from all over the political spectrum,” Miller said. “We’re trying to improve conditions for farm animals and address the misuse of antibiotics and other drugs in agriculture…We’re very moderate in our goals.”

The divide among agricultural interests isn’t always as clear as Brunner seems to define it. With the debate underway in the Senate on the 2012 farm bill, the Humane Farming Association and much of the farming establishment, including the pork and poultry producers, as well as the American Farm Bureau, are allies on one big issue in particular. They oppose an amendment that would set federal standards for the egg industry, including the size of chicken pens.

On the other side supporting the effort are the United Egg Producers and another animal welfare group, the Humane Society of the United States.

Brunner's foundation has also given donations to groups aiding veterans, disabled teenagers, religious causes and others, according to federal tax records.

But perhaps anticipating that the $10,000 foundation gift from one of his children to what he now calls a group with a “dangerous” agenda could be a lightning rod, Brunner tried to set some ground rules. He said that he expects that families would remain off limits from political attacks during the campaign.

“I will keep this campaign focused on the issues and I fully expect my fellow opponents to do the same,” he said.”