Does your cow’s hair coat cost you money?
Several factors can delay shedding, some manageable and some genetic.
By Randie Culbertson
Does your cow’s hair coat cost you money? The short answer is YES! Walk through your cow herd in late May or early June and take a close look at your herd. You will notice some variability in hair coats for you herd. Some cows will already be slicked off, while others will still be lugging around a shaggy winter coat well into the breeding season.
The difference isn’t just cosmetic, it could be costing you pounds at weaning and pregnancies on your next calf crop.
The weight of a winter coatResearch from North Carolina State University put hard numbers on what many producers have long recognized for years. In a 2010 study, calves from cows that shed their coats by March weighed an average of 57 pounds more at weaning compared to calves from cows that held onto their winter hair until July.
The mechanism in straightforward: cows that carry their winter coat into the heat of summer are more susceptible to heat stress. Heat-stressed cows cycle later, conceive later resulting in later born calves, and have an increased chance of being open at the end of the breeding season. Calves who are born later in a calving season have lighter weights at weaning. By the time you add up the reduced conception rates and lighter weaning weights, a rough-coated cow can quietly chip away at operational profitability year after year.
It’s not just about temperatureYou might assume that a cool, wet spring gives late-shedding cows an excuse but the University of Missouri researchers recently found otherwise. Their work showed the day length, not temperature, is the primary driver of when cattle begin shedding their winter coats.
Animals that shed early do so because they respond more readily to increasing daylight, making them inherently better adapted to their environment regardless of spring weather variability.
That’s an important distinction for producers in the upper Midwest or at higher elevations, where cool springs can mask heat-stress problems that will show up later in the breeding season.
What’s holding some cows back? Several factors can delay shedding, some manageable and some genetic:
Nutrition: A heifer development study at the Iowa State University McNay Memorial Demonstration and Research Farm found that heifers on a restricted plane of nutrition retained their winter coats significantly longer than their better-fed contemporaries. Young cows, yearling and first calf heifers, also tend to shed later than mature cows, largely because they are still growing and drawing more heavily on available nutrients.
Fescue toxicosis: If you run cattle on endophyte-infected tall fescue, a rough, persistent coat is one of the classic signs of trouble. The ergot alkaloids that cause fescue toxicosis interfere with hair follicle growth and disrupt normal shedding, compounding summer heat stress exactly when you need cows to be cycling for a spring calving herd.
Genetics: Here’s where producers have a real lever to pull. Hair shedding has a moderate to high heritability, estimated at 0.35 to 0.42. For context, that's in the same range as weaning and yearling weight, traits the industry has successfully moved through decades of EPD selection. As a result, consistent selection pressure will shift your herd meaningfully over a reasonable number of generations. Several breed associations are now publishing hair-shedding EPDs, and selecting sires with favorable (low) EPD values will move your cowherd to shed earlier over time.
Scoring your herd: A simple tool with real valueHair shedding scores are a low-tech, high-value management tool. Collecting scores annually takes minimal time but builds a valuable dataset for identifying cull candidates and selecting replacement heifers with superior heat adaption. Scores run on a 1 to 5 scale.
A few scoring tips:
Collect hair shedding scores in late spring or early summer.
Score the entire cowherd on the same day for consistency.
Score bulls separately. Males typically shed two to three weeks ahead of the females, so mixing them skews your data.
Cattle shed from head to tail and top to bottom, which helps you estimate percentage shed at a glance.
The bottom lineHair shedding won’t top the list of traits in every seedstock catalog, but its economic consequences are real and repeatable no matter where you are located. Earlier shedding cows handle heat stress better, breed up faster, and wean heavier calves. With moderate-to-high heritability and EPD tools available, it’s a trait you can select for. Start by walking your pastures this spring with a scores card in hand, your paycheck at weaning may depend on what you see.
Culbertson is a cow-calf Extension specialist with Iowa State University.
