A series of rules designed to change the longstanding scale of weights for jockeys in California has been posted by the state horse racing board for the legislatively mandated 45-day public comment period.The board plans to hold a public hearing on the proposed rule changes Aug. 19 at the Del Mar simulcast facility. The action was requested by the Jockeys' Guild, representatives said, to protect riders from self-destructive behavior that produces damaging consequences on their long-term health.The proposals would repeal the existing scale of "weight-for-age" rules and replace them with amendments establishing a minimum jockey weight of 118 pounds (nude) for Thoroughbred and Arabian riders, and 123 pounds for Appaloosa, Paint, Quarter Horse, or mule riders. Apprentice allowances would not be affected.The rules would require that jockeys maintain a minimum body fat content of at least 5%. The clerk of the scales would test jockeys each racing day. A testing result of below 5% would mean a warning followed by suspension after three calendar days. A measurement of below 4% would disqualify a rider from race riding. Compliance would be optional for jockeys licensed prior to Dec. 31, 2003.All horses would carry 10 pounds of riding gear from withers to rump. The riding gear amount would be in addition to jockey weight, and reported separately to the public. As a result, the standard minimum weight a Thoroughbred horse would carry is 128 pounds.The written comment period closes Aug. 16.