The Ocala Breeders' Sales Co. (OBS) faces a challenge with its August yearling sale that opens Monday in Central Florida and runs through Friday. There are 1,498 horses catalogued, a total that is up 23.4% from last year's figure of 1,214.An increase in supply outstripped demand at the Fasig-Tipton Kentucky July select yearling auction earlier this year, where the gross revenue, average price, and median price all dropped while the buy-back rate rose. OBS will be trying to avoid the same fate.Like the Fasig-Tipton Kentucky sale, the OBS auction depends heavily on yearling-to-juvenlie pinhookers as buyers. Earlier this year, pinhookers' profits dropped when the growth in the market for 2-year-olds in training slowed down.However, Tom Ventura, the OBS general manager and director of sales, is optimistic that pinhookers still will participate enthusiastically."The range (in prices) at our sale is always comfortable for them to buy in, so I don't think that it (the slowdown in the juvenile market) will impact it," he said.Much of the increase in numbers at this year's sale is due to the first phase of the dispersal of Farnsworth Farms stock. There are 104 Farnsworth yearling in the catalogue.The catalogue for the opening session Monday has 280 select yearlings and 42 Farnsworth preferred yearlings. There are open sessions Tuesday, Wednesday, Thursday, and Friday. Selling begins each day at 11 a.m. (EDT).