Jim McAlpine, president and chief executive officer of Magna Entertainment Corporation (MEC), and Steve Sexton, president of Churchill Downs and Ellis Park, have been appointed by the Thoroughbred Racing Associations of North America (TRA) to serve on the Management Committee of Equibase Company. McAlpine will represent the Mid-Atlantic region and replace Martin Jacobs; Sexton replaces Bryan Krantz. ...Jack Knowlton, managing partner of Sackatoga Stable, will be a special guest at National Museum of Racing's free Countdown to the Triple Crown program at 4 p.m. April 26. Knowlton and partners own Funny Cide, a New York-bred contender for the Kentucky Derby (gr. I). Held in the Museum's Hall of Fame Theater, Countdown to the Triple Crown features video highlights and expert opinions on Derby hopefuls. Knowlton joins program host Mike Kane and panelists Bill Heller, and Michael Veitch. Free past performances donated by Daily Racing Form will be available. ...Morris Day and The Time will kick off the Friday night concert series at Hollywood Park on April 25. Racing action on Friday nights begins at 7:05 p.m. with the standard post on other days at 1:20 p.m.... "Horsing Around" a piece for the Food Network featuring Al Roker, is scheduled to air on the network on April 27 at 9 p.m. Roker will be sampling food from the areas surrounding the Triple Crown tracks. Churchill Downs, Pimlico, and Belmont Park. The feature will also air on April 28 (midnight), May 3 ( 4 p.m.), and May 11 (4 p.m.).