Friday's Kentucky Oaks (gr. I) lost another contender Tuesday when trainer Carl Nafzger said Belterra will not run in the race for 3-year-old fillies."We don't have time to properly prepare her," said Nafzger, who had been on the fence about Belterra's status. Belterra, who captured the Golden Rod Stakes at Churchill Downs last fall and finished third in the Bonnie Miss and Ashland Stakes this year, underwent throat surgery on April 8 for an entrapped epiglottis.The daughter of Unbridled races for her breeder, Robert Manfuso."She's doing fine," Nafzger said Monday. "Every day she gets better. Every day her coat looks better. And every day she is training good. We're just missing a couple of little things. It's a question of whether she recovered from the surgery or not. She was under anesthesia. That will take a horse's punch away. The surgery has been a success. But our debate is this: Is the stress of a race like this going to set her back six weeks, or two months, or three months. Or will she be able to bounce right back? Also, there is this concern: What if she makes a move and her system just can't finish it and she ends up flat?"Tempera, the champion 2-year-old filly of 2001 who was expected to be one of the favorites in the Oaks, was euthanized Sunday night at a veterinary clinic in Lexington, Ky.Nafzger said either the Black-Eyed Susan at Pimlico or a test against males in the Lone Star Derby would most likely be Belterra's next outing.