Sports briefs

Safety changes coming to Kentucky Derby Nearly a year after the first fatal injury at America's most famous horse race, Churchill Downs announced Monday it is beefing up safety requirements ahead of this year's Kentucky Derby.

The company is enacting more than 20 changes, ranging from enhanced drug testing to limits on whips and racing ages, in time for the start of the spring meet at its signature track in Louisville, Ky.

While some of the changes, such as testing for steroids, already were required under new state racing regulations, Churchill is taking the lead on other elements. For example, the dirt track at Churchill Downs will be subjected to rigorous performance testing using a robotic hoof device that aims to simulate the force and speed of a horse.

"We think we've always had one of the safest racetracks in the country, but we think these initiatives will make us even safer," said Jim Gates, general manager at Churchill Downs racetrack.

Racehorse safety was thrust into the national spotlight after the filly Eight Belles finished second in last year's Derby, only to pull up lame as she jogged past the finish line. An autopsy showed compound fractures in both front legs, and the horse had to be euthanized on the track.

Although Eight Belles' trainer, Larry Jones, has long argued it was a fluke accident that had nothing to do with the racing surface, he praised Churchill for the changes Monday and expressed satisfaction the death of one of his most beloved pupils might have helped make the sport safer.

• An accident involving eight horses at Toronto's Woodbine Racetrack left one driver with a broken ankle and sent two others to the hospital. The accident occurred on the backstretch of the Ontario Boys Pacing Series when favorite Warp Speed fell while running third, unseating driver Mario Baillargeon and causing an eight-horse pileup.

The International Association of Athletics Federations wants to expand its worldwide appeal outside Europe. It will add two meets in the United States (New York and Eugene, Ore.) and one in China, with a likely extension into the Middle East. The Diamond League replaces the Europe-based six-meet Golden League.

"The dream came through," IAAF president Lamine Diack said. "We will have all the best meetings of the IAAF Diamond League going round the world."

High-level competition involving track and field's top names often falls through because of financial disputes among agents. The new series hopes to address this problem.

Tennis: Serena Williams beat sister Venus to win the Billie Jean King Cup, finishing off the return of women's tennis to New York's Madison Square Garden with a 6-4, 6-3 victory. Serena beat Ana Ivanovic 6-3 and Venus beat Jelena Jankovic 6-4 at the start of the one-night exhibition, which brought women's tennis back to the Garden for the first time since 2000. ... Fourth-ranked Andy Murray will miss Britain's Davis Cup match against Ukraine this week because of a lingering virus. Murray said he hasn't recovered from the illness that forced him to pull out of last week's Dubai event.

Auto racing: The tax evasion trial of two-time Indianapolis 500 winner Helio Castroneves began in Miami. The "Dancing with the Stars" champ faces possible prison time if convicted of charges that he conspired to hide about $5.5 million in income from the IRS using offshore accounts.