Because most of this region received substantial rainfall in June, July, and August, hay supplies in this part of the state are as good as it’s been in a while. However, September has been hot and dry so far and we all know that winter is just around the corner, so folks should soon be making plans for supplemental hay feeding. While a lot of cattle producers put up their own hay supply, many rely solely on buying hay to fill that need.
Let’s take some time and put hay purchasing decisions on equal footing. We’ll examine how to price hay equally by weight. When buying hay, too many producers only ask about the price per bale without knowing anything about the weight or quantity.
It should be stated that folks that buy hay “by the ton” are already where we should be. When you purchase hay by the ton, then one really does not care what size the bale is. If you stack a flatbed trailer with 4X4’s or 5X6’s, purchasing by weight is the smartest way to go.
Thus, for the many cattlemen who still buy hay by the bale, it seems a nearly impossible task to eyeball a bale of hay and determine the quantity of hay that’s within it. To make it more difficult, you must match the asking price of one seller to other sellers’ prices, by trying to closely match bale size. It truly is a daunting task.
To help us get a better idea of the volume of hay in a bale, let us use some basic equations that we learned in geometry in high school. A round bale is nothing more than a cylinder. The volume of a cylinder is measured as 3.14 times the radius squared multiplied by the height of the cylinder (V= π R2 x H). If we apply that to a 4X4 bale of hay, we come up with a volume of 50.27 cubic feet. If you take that same formula and apply it to a 5X5 bale of hay, then you come up to 98.18 cubic feet. Surprisingly, a 5X5 bale is indeed double the volume of a 4X4.
For those interested in cubic feet of the other common bale sizes, here are the basic bale sizes: 4X4 = 50.27 4X5 = 78.54 4X6 = 113.10 5X5 = 98.18 5X6 = 141.37 Research from several universities and commercial sites say that hay density can vary from 9 to 12 pounds per square foot. In round hay bales examined in Angelina County, very loose bales were just under 9 lbs. per square foot and tighter bales were as high as 11 lbs. per square foot. For simplicity, let’s hit the middle and assume a density of 10 lbs. per cubic foot. At 10 lbs./square foot, a 4X4 would be about 500 lbs. and a 5X5 would be just under 1,000 lbs., coming in around 980 lbs.
Even with the assumptions above, using a good set of public scales would be an excellent choice. At a local feed business in Cuero, it costs $15 to use the scales to weigh a load of hay. So, for $30, you can take a full load of hay and then an empty load. Take the difference between the two weights and divide it by the number of bales. You’ll then know the average weight of the bales. Bonus tip, fill up your gas tank before each weight to eliminate any error caused by the fuel weight.
Not convinced? Let’s take a hard look at a $60 bale of hay. If it is a loosely wrapped 4X4, then you could be spending $0.13 per pound. But if was a tightly baled, 5X5 round bale, you could end up with an investment of $0.06 per pound of hay.
And finally, let’s look at this another way. If you are confident that the $60, loosely wrapped (at 9 lbs. per square foot), 4X4 was a good purchase, then you could also justify spending $140 on a tightly wrapped (at 11 lbs. per square foot), 5X5 bale. Run the math for yourself.
Cattlemen run a business with incredibly tight margins. I tip my hat to those who do well year after year with increasing input costs and facing unpredictable weather. Let the numbers above encourage you to make wise decisions as you consider purchasing hay.
Now, this article only discusses hay quantity, that is, the big differences between weights of hay bales. There are also big differences in hay quality, and thus, quality should also be a major consideration. We’ll address hay quality in a future news article.
This article was adapted from an article published in August 2023 by Cary Sims, County Extension Agent for Agriculture and Natural Resources in Angelina County, Texas.
