With cooler nights settling in and the rains finally returning, many cattlemen are feeling confident heading into winter. But before the real cold arrives, there’s one thing worth double-checking: your hay math. 

Most producers assume they have enough. Many do, but the people who find out in late January that they are short never enjoy the discovery.

Getting started on the math; a mature cow will consume two to two-and-a-half percent of her body weight each day in dry matter. Texas A&M AgriLife Extension uses this benchmark across all beef nutrition work. For a 1,200-pound cow, that’s about 24 to 30 pounds of dry matter per day. 

But hay isn’t 100 percent dry matter. Most round bales are around 15 percent moisture. That means the same cow is actually eating closer to 28 to 35 pounds of hay each day, factoring in moisture content.

The next thing to factor in is waste. Ranch-based research on hay losses shows a wide range—anywhere from 5 percent to more than 30 percent. This wide range is based on how hay is stored and how it’s fed. Bales left outside take on weather and the exterior ring can ruin. 

Unrolled hay, especially in muddy feeding areas, can lose a surprising amount. Even a standard hay ring can have losses in the 10 to 15 percent range. If you want honest numbers, use 20 percent waste unless you have feeding pads, covered storage, and good equipment.

Now, most East Texas round bales are 4x5s, and they’re not the 1,200–1,400 lb bales that you’ll hear some claim. Local Extension data and hay market reports put a typical Bermuda 4×5 bale between 850 and 950 pounds, with Bahia a little lighter at 750 to 850 pounds. 

When you run the winter numbers based on Texas A&M AgriLife’s dry-matter intake guidelines, a mature 1,200-pound cow will eat roughly 4,000 to 4,200 pounds of hay across a 100-day feeding season once you factor in normal feeding losses. In practical terms, that means most producers will need four to five 4×5 round bales per cow for the winter, depending on hay quality and wastage. 

My friend Royce told me that, except for the awful winter of 2021, he has done well with only three bales of hay per cow. How? He bales hay in a heavy 5×6 round bale – significantly larger than a 4×5! If someone overheard him say “3 bales” and never understood his volume in a bale, they’d be in a heap of hurt after missing the full story.

Too many cattlemen underestimate their herd’s winter hay needs because they assume their bales weigh more than they actually do. A quick scale weight or honest estimate of bale size goes a long way toward preventing a February hay shortage. This is where many cattlemen underestimate their needs. They overvalue the weight of their bales or undervalue how much the cow is actually consuming. Being short by one bale per cow is one of the most common miscalculations.

Before we stop analyzing what we’ve got, let us agree that hay quality adds another wrinkle. AgriLife forage testing continues to show that protein and energy vary widely between bales, fields, and cuttings. A bale testing at or below eight percent crude protein won’t meet a dry cow’s needs without supplementation. A bale at twelve percent typically will. Producers who haven’t tested their hay are guessing, and guessing in winter is expensive. A quick forage test from a quality Forage Testing Lab can make the difference between an efficient feeding program and a costly supplement bill.

Now that we have run all the math, let’s take stock of what’s in the barn. Count your bales. Multiply by their weight—actual weight if you can get one on a scale. Divide that total by what your cows will need over the feeding period. Rains have come, cool weather is settling in, and we’re entering the stretch where hay usage climbs. Knowing your inventory today keeps you from making rushed and expensive decisions later.

If you’re short, address it now. Buying hay in December is cheaper than scrambling to buy hay in February. Reducing waste is another easy win—feed rings, pads, and controlled feeding all stretch your supply. Testing hay lets you match supplements accurately instead of overfeeding. 

With live cattle prices at historic highs, producers still need to watch their expenses to maximize income. AgriLife’s position has always been the same: supplementing a cow early is cheaper than trying to re-condition a thin cow later. Winter feeding doesn’t have to be complicated, but it does have to be accurate. A few minutes spent running your numbers today can save you a whole lot of trouble before winter is done.