LEXINGTON, Ky. - Frank Stronach's Adena Springs breeding operation recorded its sixth consecutive year as North America's leading breeder by earnings in 2008, the Jockey Club Information Systems announced Tuesday.\nAdena Springs topped the rankings of breeders both with and without partners. By itself, the far-flung program - which has farms in Kentucky, Canada, and Florida - bred the winners of 603 races from 3,671 starts for combined earnings of $19,217,703. Alone and with partners, Adena Springs bred the winners of 604 races from 3,679 starts for total earnings of $19,247,705.\nAdena Springs won Eclipse Awards as leading breeder in 2000, 2004, 2005, 2006, and 2007. Stronach also has won three Eclipses as top owner, in 1998, 1999, and 2000.\nStonerside Stables, which bred 2008 Breeders' Cup Classic winner Raven's Pass and Breeders' Cup Juvenile winner Midshipman, was a distant second on both the non-partnership and with-partners lists, but Stonerside had far fewer horses. The operation, owned by Robert and Janice McNair until September, when Sheikh Mohammed al-Maktoum bought it, bred by itself the winners of 98 races from 518 starts for earnings of $7,433,027. Including partners, Stonerside bred the winners of 130 races from 711 starts for a total of $8,521,912.\nRounding out the top 10 individual breeders' list were Eugene Melnyk, with $6,410,230 and 231 wins; Brereton C. Jones, $6,339,254 and 216 wins; WinStar Farm, $5,460,005 and 89 wins; Juddmonte Farms, $4,924,494 and 51 wins; Sherman Family Thoroughbreds, $4,839,702 and 309 wins; Sez Who Thoroughbreds, $4,780,068 and 196 wins; Padua Stables, $4,773,351 and 192 wins; and Everest Stables, $3,966,631 and 116 wins.\nThe remainder of the top 10 list for breeders and partners were Will Farish, $6,950,184 and 193 wins; Brereton C. Jones, $6,692,257 and 230 wins; Eugene Melnyk, $6,425,830 and 232 wins; WinStar, $6,092,313 and 122 wins; Sherman Family Thoroughbreds, $5,160,946 and 339 wins; Sez Who Thoroughbreds, $4,944,584 and 201 wins; Juddmonte, which had no starters bred in partnership, $4,924,494 and 51 wins; and Padua, $4,819,874 and 194 wins.\nLists of the top 200 breeders in North America by 2008 earnings are online at www.equineline.com.\nExchange Rate colt heads OBS sale\nThe Ocala Breeders' Sales Company's winter mixed sale kicked off Tuesday in Ocala, Fla., with an $87,000 Exchange Rate colt as the session leader at 5 p.m.\nEisaman Equine bought the Florida-bred yearling from agent Janie Roper. The gray or roan colt is out of the Tabasco Cat mare Social Scene. Named Noble Exchange, he is a half-brother to stakes-placed Winsome Charm. His family includes graded performers Kew Green and Little Hans.\nThe two-day auction's Tuesday session, a consignor-preferred session, was still under way, with 264 horses in the catalog for the day. The sale was to end Wednesday with an open session cataloging 349 horses.\nNiagara Causeway to stand for $3,000\nLaBahia Stud's Grade 3 winner Niagara Causeway will enter stud this year at Doug Arnold's Buck Pond Farm in Versailles, Ky. The 6-year-old Giant's Causeway horse will stand for $3,000.\nNiagara Causeway won Santa Anita's Grade 3 Tokyo City Handicap in his final start on March 29, establishing a track mark of 2:29 for 12 furlongs on Santa Anita's synthetic surface. He also finished second in the Grade 3 Cinema Breeders' Cup Handicap in 2006 on Hollywood's turf course. Niagara Causeway ends his racing career with 4 wins from 20 starts and earnings of more than $255,000.\nNiagara Causeway is out of Irish champion filly Theoretically, a daughter of Theatrical.