Sterling Pound, dam of the successful young sire Exchange Rate, has died at age 18, Middlebrook Farm announced Saturday.\nAccording to a release issued by the central Kentucky farm, the Seeking the Gold mare was euthanized Jan. 9 at Hagyard Equine Medical Institute "due to progressive infirmities."\nSterling Pound was carrying an Empire Maker foal when she died.\nA daughter of Spectacular Bev, Sterling Pound was a homebred for Heidi Doubleday and carried Doubleday's silks to victory in five races, most notably in the Grade 3 Honey Bee Handicap in 1994. She earned $155,619 in her 17-race career.\nExchange Rate was Sterling Pound's first foal. A gray or roan Danzig colt, Exchange Rate won the Grade 2 Tom Fool in 2001 and the Risen Star Stakes in 2000. He placed in four other stakes, all graded. He since has sired such stakes performers as Grade 1 winners Ermine and Swap Fliparoo.\nExchange Rate, who was 13th among sires of 2-year-olds last season, stands at Three Chimneys Farm in Kentucky. Sterling Pound also produced the Grade 3 winner Sabre d'Argent, now a stallion at Bridlewood Farm in Florida.\nSterling Pound's last foal is an unnamed Bernardini filly born in April 2008. Sterling Pound will be buried at Middlebrook.