Today's story showing how Sen. Bill Nelson gets a hefty tax break for having a half dozen cows on his land in Brevard County drew a colorful response from his chief rival, Connie Mack.

"Holy Cow(s)!! Bill Nelson's Bovine Boondoggle Tax Shelter," read the subject line of one of several e-mails the Mack campaign has sent out on the matter.

Mack accused Nelson of hypocrisy for taking the tax break while bemoaning tax loopholes. "Not only has Senator Nelson cried out that local and county workers are being robbed by tax loopholes, we now know the identity of that robber is none other than Bill Nelson himself. Senator Nelson's six cows may have found him a legal way to avoid paying the taxes that help pay the county workers he claims to defend, but it is certainly the despicable and dishonorable way."

George LeMieux, another Republican seeking to take on Nelson, tweeted: "@ SenBillNelsoncalls for closing tax loopholes but saves thousands by exploiting them. # hypocrisy # 6cows."