The Board of Health has heard testimony regarding its plans to impose new regulations on the city’s pig farms. At its meeting Tuesday night, the three-member board heard from proponents and critics of the latest draft of a proposed regulation for piggeries, which was based on rules adopted in Tewksbury to prevent large-scale piggeries from being established in the town. Local farmers told the board that the proposed rules would force them out of business, while proponents said the proposed regulations should go even further, with increased setback requirements that would keep swine well away from nearby dwellings, wetlands, and waterways. The Health Board took the comments under advisement, and will be incorporating some of the suggestions into a final draft of the proposed regulation. The board has been working on the regulations for several months, and is expected to address the issue again at its next meeting, scheduled for April 10.