Round bales have been a popular feed technology in the beef industry for many years.  However, there are many challenges to buying (or producing) and using round bales correctly and cost effectively.  Round bales are often priced by the bale but the amount of hay in a bale depends on bale size and density.  For example, assume a 5x6 round bale (5 feet wide and 6 feet in diameter or height) is priced at $52.50/bale.  If the bale weighs 1,500 pounds, the price is equivalent to $70/ton.  A comparable 5x5 bale (with equal density) would weigh 1,046 pounds and be priced at $36/bale ($70 ton) and a 4x5 bale (with equal density) would weigh 833 pounds and be priced at $29/bale. 

The density of round hay bales varies considerably and typically ranges between 9 and 12 pounds per cubic foot (lb./ft3).  In the example above, the bales are assumed to have a density of 10.61 pounds per cubic feet.  Bale density varies depending on the type of forage, adjustment of the baler and skill of the baler operator.  Bales with lower density weigh less; are more difficult to handle and transport; and have more storage losses.  If the 5x6 bale in the example above has a density ten percent less (9.55 lb./ft3), the bale weighs 1,350 pounds while a density 15 percent less (9.02 lb./ft3) results in a bale weight of 1275 pounds.  If the 5x6 bale is priced at $52.50/bale, the per-ton price increases to $78 and $82 for the lower density bales.

Round bale use inevitably results in storage and feeding losses. Hay loss with round bales varies widely depending on storage and feeding management.  Well managed bale storage and feeding might limit losses to ten percent but combined storage and feeding losses frequently range up to 50 percent or higher.  Round bales stored outside, uncovered and on the ground and fed in unrolled, exposed bales or in simple open-sided ring feeders will have the biggest losses, easily 30 -50 percent. In contrast, bales stored inside or covered, off the ground and fed unrolled or in cone style feeders can limit losses to 5-15 percent. The amount of hay actually consumed by cows drops dramatically with increased storage and feeding losses.  At ten percent loss, hay consumption is 1,800 pounds for each ton of hay; at 25 percent loss, hay consumption is 1,500 pounds and at 40 percent loss, hay consumption is 1,200 pounds. At $70/ton, storage and feeding losses increase the effective hay price to $78/ton (10 percent loss); $93/ton (25 percent loss); and $117/ton (40 percent loss).  Storage and feeding losses combined with low bale density increases hay price further.  The low density bale above (5x6 at 1275 pounds, priced at $52.50/bale) results in a hay cost of $91/ton (10 percent loss); $110/ton (25 percent loss); and $137/ton (40 percent loss).  The combination of low bale density and high storage and feeding losses result in actual hay cost nearly double ($137 versus $70) the stated per-ton price of hay.

Whether hay is purchased or produced, cow-calf producers face the same challenges with round bales.  Without knowing the weight and the storage and feeding losses associated with round bales, producers cannot possibly know the true cost of hay nor manage the quantity of hay consumption and cow herd nutrition.  As important, or perhaps more important, than the quantity, is the quality of round bales.  The cost of hay ultimately depends on the pounds of crude protein and energy delivered to the cow.  Hay quality and nutrition cost will be the subject of part 2.