Although hay feeding has stopped on most farms and cows are out on grass, it is important to look at the value of hay as many start harvesting this year's hay crop.
Every ton of hay contains approximately 40 lbs. of N, 20 lbs. of P, and 50 lbs. of K. However, it is important to calculate N losses at about 75%, thus only about 10 lbs. of N are returned to the soil. The values of P and K are accurate to what would be returned.
Current fertilizer prices for Illinois published by USDA are: N $0.59, P $0.45, K $0.57.
Thus, with current nutrient values, hay has a fertilizer value of $54.85 per dry ton. Assuming a 1200lb round bale is 15% moisture, the nutrient value per bale is $27.97.
This figure is good to know whether you are making your own hay or purchasing hay.
If you are figuring what it costs you to make hay on your farm, add mowing, raking, and baling at 19.81 per bale (2013 Iowa Custom Rates). This results in a cost of $47.78 per bale sitting in the field (roughly $80 per ton assuming a 1200 lb. bale). Other costs would include moving the bales from the field, some additional time and labor in handling the bales, and the use of equipment to transport the hay. Realize equipment, labor, and most other costs go up if yields are below average.
If you are purchasing hay, the fertilizer value of hay is important to consider, realizing that if these nutrients are evenly spread over pastures during winter feeding, the benefit could be quite large to helping distribute additional nutrients to poorer fertility sections of a pasture. With a little thought and management when feeding hay, producers can build pastures up, reduce manure handling, and help make the most out of purchased hay.
Making profitable decisions are based on knowledge. When all costs are accounted for, the cost of producing hay is relatively high when compared to purchasing hay. This will differ from farm to farm. Nevertheless, the numbers are worthy of a look. In my experience, those producers that reduce the need for purchased feeds and limit hay feeding are more profitable than those that devote significant time, money, and resources to producing and feeding hay.