Pennsylvania horseman Marshall Jenney, who bred leading sire Danzig in partnership, died Sunday at Johns Hopkins Medical Center in Baltimore after a brief illness. Jenney, who also bred English and Irish champion Mrs. Penny and millionaire Yankee Affair, was 60.Jenney, who operated Derry Meeting Farm near Cochranville, Pa., was honored as Pennsylvania's leading breeder on several occasions. He bred Danzig in partnership with William S. Farish, and consigned the colt in the name of his farm to the 1978 Saratoga yearling sale. Henryk de Kwiatkowski bought Danzig for $310,000, which was the fifth-highest price at the sale. Danzig went on to win all three of his races prior to entering stud at the Hancock family's Claiborne Farm near Paris, Ky., where he has sired 156 stakes winners.Jenney also bred English and Irish champion Mrs. Penny and millionaire Yankee Affair. Mrs. Penny was a group I winner in England, and a two-time group I winner in France. Yankee Affair won several grade I turf events.Jenney's connection to a leading sire didn't end with Danzig. Storm Cat, who lead the general sires list in 1999, was foaled at Derry Meeting in 1983. Storm Cat raced as a homebred for William T. Young's Overbrook Farm.Jenney, who worked briefly on Wall Street following his graduation from Princeton University, also was a noted steeplechase rider.