Plans for a wooden hay feeder are available from HobbyFarms.com. The plans show the finished feeder's front and side elevations, along with an inside view from the side. Below the diagrams is a list of the cuts of wood that are required to construct the feeder. The required plank lengths, mitre cuts and bevels are included on the plans, but the planks' width and thickness are not stated.
A similar plan is available from Grit.com; however the instructions are written rather than diagrammed. The instructions are for building a 4-foot hay rack and bunk feeder that is suitable for sheep, goats and ponies. Materials are estimated to cost under $80, but reusing scrap wood can help lower the cost. The finished feeder holds 1 1/2 square hay bales.
Repurpose an old 55-gallon plastic drum for a different style of hay feeder. Feed stores, industrial exchange programs and materials recycling programs may have old plastic drums for sale. Ensure that the drum did not contain toxic materials before putting it to use as a feeder. Use a circular saw to cut a large opening in the side of the drum, and clean it out using detergent. File down any rough edges on the opening.
Drill holes on the other side of the drum and use U-bolts to attach it to a fence or other object. Drill drainage holes in the bottom of the feeder, and stock it with hay.