Organizations representing horse breeds across Massachusetts will join together to support the construction of an equine center in the state that would also include a racetrack to replace Suffolk Downs, officials of the group leading the effort announced on Tuesday. The group, the New England Horsemen’s Benevolent and Protective Association, announced preliminary plans for the facility on Tuesday in advance of the release of an economic study it has commissioned from the University of Massachusetts Amherst. The study is not expected to be released for six weeks, said Lou Raffetto, a former racetrack executive who was hired last year as a consultant to the New England HBPA, but it will argue that the facility could generate millions of dollars in revenue annually. Preliminary plans for the equine facility call for a grandstand for 4,000 spectators, a one-mile dirt track, and a seven-eighths-mile turf course, Raffetto said. The facility would also include accommodations for equine stadium events, a Thoroughbred retirement facility, a veterinary hospital, and links to riding-trail networks, according to the New England HBPA. The New England HBPA has said that it plans to issue bonds backed by payments from the state’s Race Horse Development Fund to pay for construction of the facility. The fund, which was established in 2011 after voters approved a referendum providing for three stand-alone casinos and one slots parlor in the state, currently receives money from a casino at Plainridge Park Casino, a harness track owned by Penn National Gaming Inc. that received the slots license. No other casino has opened in the state. Raffetto said that if the New England HBPA is able to use the backing of the Race Horse Development Fund, the construction and operation of the facility would be fully funded without any state assistance. He said the facility would be structured as a non-profit. Currently, the Race Horse Development Fund is required to distribute 75 percent of its proceeds to Thoroughbred purses and breeders’ awards, with the remainder going to Standardbred interests. Last week, harness interests attempted to convince the legislature to change the formula to favor Standardbred funding, citing the precipitous decline in live Thoroughbred racing dates in the state since Suffolk was passed over for a casino license in 2014. Last year, Suffolk held three live racing dates under an agreement with the New England HBPA. This year, Suffolk has been awarded six live racing dates. The track’s owners have said they continue to explore opportunities to redevelop the East Boston property now that a casino is off the table. Raffetto said that the new equine facility would need to be located outside of the greater Boston area to hold down costs. The plans call for a footprint of “at least 300 acres, probably closer to 400,” Raffetto said.