by Gus Burns | The Saginaw News Tuesday April 21, 2009, 11:19 AM Two years ago, the Saginaw Valley Equine Clinic in Freeland often paid more than $500 for mares to use as surrogates. Now, the market has dropped so low that owner Dr. Brad T. Cumper gets mares for free. He even screens them. "People are happy that we'll take them and feed them and give them a job," the veterinarian said. The price of hay and bedding in the strained economy have evaporated the market for some horses, leading to growing desperation among some owners who can't maintain...