Yes, this creates a Worker’s Compensation issue. In order to be properly insured, the boarding stable would need to have Workman’s Compensation. Even though there is no money being exchanged, the trade has a value and would be considered remuneration. The same would be true for a person receiving a place to live for cleaning stalls, or doing other jobs around the ranch. You would need to declare the value of the board or rent on your payroll reports.