Historical clue formulations

• Operator of a stud farm — 2022-06-14
• Rancher, typically — 2012-02-23
• Person who raises and sells pups — 2009-07-23
• One with a stake in 48-Across, say — 2009-05-02
• Owner of a stud farm — 2007-09-02
• Strain improver — 1995-03-11