The Virginia Senate narrowly passed a bill on Monday that would allow Colonial Downs and its offtrack betting parlors to operate Instant Racing machines, devices that use horse races that have already been run to generate random numbers for payouts to winning bettors. The Senate voted 21-19 to pass the bill, according to the website for the legislative body. Similar measures have passed the Senate previously, only to be rejected in the state’s conservative-leaning General Assembly. Instant Racing machines are currently in use in Arkansas, and last year the Kentucky Horse Racing Commission approved rules allowing for their installation at the state’s racetracks and one off-track betting location. Although a circuit-court judge in Kentucky has ruled that the commission acted within its power to approve the devices, the ruling has been appealed by anti-gambling groups who contend the machines violate state prohibitions on slot machines. Under the bill passed in Virginia, 42 percent of the net revenue from the machines would go to the state, and 45 percent to Colonial. Six percent would be directed to subsidies for Thoroughbred and harness purses, and 2 percent would go to subsidies for breeders. The purse and breed-development subsidies would be capped at $30 million each per year. Colonial Downs is Virginia’s only racetrack, and it holds a Thoroughbred and Standardbred meet each year. The track also owns and operates 10 offtrack betting parlors.