Pay each family their profit 3. To avoid losing your place, allow discussions, government meetings, votes, etc. Scorekeeping is easier on a spreadsheet. The senators may pay themselves a salary. They may hire a law enforcer to be sure the rules are followed.
Taxation raises several interesting issues.
Taxes can be used to get money for government projects but also to encourage or discourage certain behavior. They might discuss flat vs. progressive taxes. They may want to use taxes as a way of discouraging richer families from buying more and more cows. Annual spending on infrastructure, social services, defense, etc. Salaries for senator, treasurer, law enforcer, etc.