Jeff Lehmkuhler has helped guide beef farmers for two and half decades, but he’s never seen lower hay quality than what he witnessed in 2025. The University of Kentucky extension beef specialist has some concerns related to the lack of higher quality hay.
“Many spring-calving cows are now in their last trimester of gestation, which is a time when the fetus has its greatest rate of growth,” Lehmkuhler states.
This additional growth, coupled with the cow’s need for mammary gland development and colostrum formation, puts a future new mama into a much higher nutritional category. Not meeting her needs can result in a weak calf at birth and poor-quality colostrum from its mother.
Next, let’s add in the recent stretch of extremely cold weather. Paul Beck notes that as temperatures drop below the cow’s lower critical temperature (LCT), energy requirements increase by approximately 1% for every degree below the LCT.
Beck, an extension beef specialist with Oklahoma State University, says that for a cow in good body condition (a body condition score [BCS] of 5) with a thick winter hair coat, the LCT is about 32°F. When temperatures fall to 20°F, her energy requirement jumps by about 12%, raising her total digestible nutrients (TDN) requirement from 12.5 to roughly 14 pounds per day. Now think about what happens during a weather stretch when you wish the temperature would rise to 20°F.
The situation escalates for a thin cow (BCS 4) with a thin hair coat. These cows already need to gain body condition to improve the likelihood of rebreeding. Their LCT is closer to 40°F. When temperatures drop to 20°F, energy requirements rise by about 20%, raising TDN needs from approximately 13.3 to 16 pounds per day.
Poor hay equals poor doers
Given the current value of feeder calves, Lehmkuhler doesn’t think farmers can afford to feed hay without knowing its nutrient content, especially since there’s so much extremely low-quality hay on many farms.
The Kentucky beef specialist recommends pulling forage samples to document what nutrient levels exist in unique lots of hay.
“Evaluate if your hay will meet the nutritional requirements of late-gestating cows,” Lehmkuhler asserts. “If your hay is not going to meet the nutritional needs for the cows, develop a supplementation program. In many instances, we see the protein level of the forage is sufficient, but the hay is low in energy. However, you need to test the hay to really know what nutrients may be short,” he adds.
Lehmkuhler recommends beef producers use their forage test results in conjunction with the University of Kentucky Forage Supplement Tool to evaluate supplementation needs. The tool utilizes four items from your forage test report: dry matter, neutral detergent fiber, crude protein, and total digestible nutrients.
Three stages of production for mature cows can be selected, which include mid-gestation, late gestation, and lactating. Preloaded supplements are available to select for use.
Lehmkuhler explains that the user’s information is evaluated to provide an estimate of the supplementation needed to meet the nutritional requirements of mature cows. For example, a late-gestating cow in good condition that is provided hay containing 88% dry matter, 8% crude protein, 68% neutral detergent fiber (NDF), and 53% TDN would need 1.6 pounds per day of a 50:50 mix of corn gluten feed and soyhulls.
Lehmkuhler concludes, “I use a baseball analogy: The program may not be perfect and won’t get you a home run, but it will often provide you a double or triple and prevent you from striking out on your cows’ nutritional needs.”
This winter, feeding spring-calving cows correctly will need to account for a lot of variables, so consider cow condition, weather, and hay quality when developing a supplementation plan.
