On paper, a beef-on-dairy steer may look about the same as conventional beef at finishing. But at the bunk and in the rumen, it’s a very different animal.
While physically these animals are identical, beef-on-dairy cattle are running on a more expensive engine, according to University of Nebraska beef systems Extension educator Alfredo Di Costanzo. During his recent webinar on beef-on-dairy fiber requirements, he used grazing data to highlight the different fiber needs for this terminal cross.
Different Genetics, Different Requirements
During a recent study, when Di Costanzo compared beef breeds to beef-on-dairy animals on pasture, the results were consistent. The traditional beef cattle converted forage to gain more efficiently, while the beef-on-dairy group gained more slowly and finished at lighter weights. To Di Costanzo, it showed the genetic influence of the dairy breed increases the energy required for growth.
“Because I put dairy [genetics] on this beef animal, the maintenance requirements have gone up,” he explains. “If we’re going to increase fiber inclusion, we’re going to have to do it with a better-quality forage.”
Why Low-Quality Fiber Doesn’t Cut It
The challenge is not just that beef-on-dairy cattle use more energy. It is also how quickly feed moves through their systems.
Dairy and dairy-cross animals tend to have a faster rate of passage through the rumen, Di Costanzo notes. That may not sound like a major difference, but it changes what kind of forage they can actually use. A stemmy, lower-quality roughage a beef steer might handle fairly well can end up acting like little more than gut fill in a Holstein-influenced calf.
While this study focused on cattle on pasture, the same idea applies at the feed bunk.
Di Costanzo explains lower-quality fiber does not stay in the rumen long enough to be properly digested for these beef-on-dairy crosses. In nutrition terms, that can create negative effects where poor-quality roughage drags down the performance of the entire ration by taking up space without delivering much energy in return.
“Lower quality forage, for me, means less time for ruminal digestion and more time, too, for negative associative effects,” Di Costanzo warns.
Those negative effects can show up as lower total digestibility, poorer feed efficiency and more variability in intake, especially when cattle are already being pushed on a high‑concentrate program. For beef‑on‑dairy cattle, that means cheap, low‑quality roughage is rarely worth the investment. Di Costanzo notes every pound of dry matter must work harder, making junk roughage a poor economic fit.
Is Cheap Roughage Costing You Gain?
Biologically, cattle can get by on very little fiber if energy and protein are there, Di Costanzo notes.
“At zero or near-zero inclusion of fiber in the diet, cattle are continuing to thrive,” he adds. “There’s really no NDF requirement for maintenance or growth.”
But in a real‑world feeding program, beef‑on‑dairy cattle need rations that turn a profit, not just keep them alive. That’s why Di Costanzo warns against using cheap, low‑quality hay or residues just to say the diet has enough roughage.
Instead, he suggests aiming for about 10% to 15% NDF from good‑quality forage. For many feed yards, that might mean favoring well‑processed silages or higher‑quality forages over the cheapest roughage available. The goal isn’t to stuff the rumen. It’s to support muscle gain without sacrificing efficiency.
Quality Over Quantity
Fiber decisions are not just about keeping the rumen healthy. They also affect how cattle perform on feed and the value you get when it’s time to sell.
Adding more fiber to beef-on-dairy diets can help support greater feed intake, but there’s a limit. Average daily gain starts to drop quickly once physically effective NDF goes above about 15.5%, and feed conversion efficiency also declines. The challenge for producers and nutritionists is finding the sweet spot where cattle eat enough without slowing growth.
Overall, the type of NDF is less important than making sure cattle get the right amount of good-quality fiber. Hitting that balance helps support intake, maintain feed efficiency and keep beef-on-dairy steers performing at their best. For beef on dairy cattle, a well-planned grower ration with the right balance of concentrate and quality fiber can set cattle up for a better finish.
