Cutting hay into finer pieces (7.68 mm instead of 11.54 mm) reduced dietary fiber content by 1.9 percentage points but did not affect beef cattle growth, meat quality, or chewing time in a 40-steer study. Research shows that finely chopped hay may help farmers make feed more uniform without harming performance, though fiber digestibility was slightly reduced and digestive health should be monitored.
Researchers tested whether cutting hay into smaller pieces affects how well beef cattle grow and digest their food. They fed 40 steers two different diets that were identical except for hay particle size: one with longer pieces and one with shorter pieces. According to Gram Research analysis, cutting the hay smaller reduced the fiber content in the diet but didn’t change how much the cattle grew, what their meat looked like, or how much time they spent chewing. The study suggests that farmers might be able to use finely chopped hay to make cattle feed more uniform without hurting the animals’ performance, though there may be some concerns about digestive health.
Key Statistics
A 2026 study of 40 beef steers found that reducing hay particle size from 11.54 mm to 7.68 mm decreased dietary effective fiber from 14.23% to 12.33% without affecting growth rate or carcass quality.
Research on 40 finishing beef steers showed that cattle fed finely chopped hay (7.68 mm) had reduced fiber digestibility compared to longer-cut hay (11.54 mm), but starch digestibility and rumination time remained unchanged.
A 2026 beef cattle study found that serum amyloid A, a marker of inflammation, tended to be higher in cattle fed longer-cut hay (P = 0.09), suggesting finely chopped hay may have minor benefits for reducing digestive stress.
The Quick Take
- What they studied: Whether cutting hay into smaller pieces changes how beef cattle grow, digest food, and chew their cud
- Who participated: 40 young beef steers (average weight 387 kg or about 850 pounds) divided into two groups of 20 each, housed in pens with 4 steers per pen
- Key finding: Cutting hay from 11.54 mm to 7.68 mm pieces reduced fiber content in the diet by 1.9 percentage points, but cattle still grew the same amount and produced meat of equal quality
- What it means for you: Farmers might be able to use finely chopped hay to make cattle feed more consistent without reducing meat production, though they should monitor digestive health carefully
The Research Details
Researchers divided 40 beef steers into two groups and fed them nearly identical diets for several weeks. The only difference was how finely the hay was chopped. One group received hay cut to about 11.5 millimeters (roughly the size of a grain of rice), while the other group received hay cut to about 7.7 millimeters (finer, like coarse sand). The researchers measured how much the cattle ate, how fast they grew, what their meat looked like after slaughter, and how well they digested different parts of their food. They also tracked how much time the cattle spent chewing and tested their blood and fecal samples to look for signs of digestive stress.
The study was designed this way because cattle farmers face a tricky problem: they need to include enough fiber (roughage) in the diet to keep the cattle’s digestive system healthy, but too much fiber reduces the energy content of the feed and slows growth. By testing whether finely chopped hay could work as well as longer-cut hay, the researchers were exploring whether farmers could use a smaller amount of finely chopped hay to achieve the same digestive benefits while keeping more energy in the diet.
This type of controlled experiment is valuable because it isolates one variable (particle size) while keeping everything else the same, making it possible to see the true effect of that one change.
Understanding how forage particle size affects cattle performance helps farmers make practical decisions about feed processing. If finely chopped hay works just as well as longer hay, farmers could potentially reduce the total amount of hay in the diet, which would lower feed costs and improve growth rates. However, if finely chopped hay causes digestive problems, farmers would need to stick with longer-cut hay despite the cost. This research provides evidence to guide those decisions.
This study was conducted at a university research facility with controlled conditions, which is a strength because it reduces confusing factors. The researchers used proper statistical methods to analyze their data and included enough animals (40 steers) to detect meaningful differences. However, the study only lasted one feeding period, so results might differ across different seasons or with different types of hay. The findings come from a peer-reviewed scientific journal, which means other experts reviewed the work before publication.
What the Results Show
The main finding was that reducing hay particle size from 11.54 millimeters to 7.68 millimeters decreased the effective fiber content of the diet from 14.23% to 12.33% of the total dry matter. Despite this reduction in fiber, the cattle fed finely chopped hay grew at the same rate as cattle fed longer-cut hay, and their meat had the same quality and weight. The researchers found no meaningful differences in how much feed the cattle ate or how efficiently they converted feed into body weight.
When the researchers measured how well the cattle digested different nutrients, they found that fiber digestibility was lower in cattle fed the finely chopped hay. This means the cattle’s digestive systems broke down and absorbed less of the fiber when it was cut into smaller pieces. However, the cattle still digested starch (the main energy source in their diet) equally well regardless of hay particle size, which helps explain why their growth wasn’t affected.
The researchers also measured rumination time, which is how long cattle spend chewing their cud (regurgitating and re-chewing food). Surprisingly, cattle spent the same amount of time ruminating whether they received long-cut or short-cut hay. This was unexpected because finely chopped feed typically requires less chewing. The researchers also found that fecal pH (a measure of digestive acidity) differed between groups on certain days, suggesting some variation in digestive conditions, though this didn’t translate to visible digestive problems.
Blood tests showed that cattle fed longer-cut hay had slightly higher levels of serum amyloid A, a protein that increases during inflammation or stress. This difference was borderline statistically significant (P = 0.09), meaning it could have been due to chance. The researchers noted this as a potential concern but emphasized that it was a minor finding. No other signs of digestive distress or health problems were observed in either group.
This study adds to existing research showing that cattle can tolerate a fairly wide range of forage particle sizes without major effects on growth. Previous research has shown that very finely ground hay can sometimes cause digestive problems, but this study suggests that moderately finely chopped hay (7.68 mm) may be acceptable. The finding that fiber digestibility decreased with finely chopped hay aligns with previous studies, which have shown that smaller particle sizes can reduce the time feed spends in the digestive system, potentially reducing fiber breakdown.
The study only included one type of hay (prairie hay) and one finishing diet formulation, so results might differ with other hay types or diet compositions. The experiment lasted only one feeding period, so seasonal effects or long-term impacts weren’t measured. The study included only 40 steers, which is a moderate sample size; larger studies might detect smaller differences. The researchers couldn’t directly measure how much time feed spent in the digestive system, which would have helped explain the reduced fiber digestibility. Additionally, the study was conducted under controlled feedlot conditions, so results might not apply to cattle grazing on pasture or in other management systems.
The Bottom Line
Based on this research, farmers can consider using finely chopped hay (around 7.7 mm) in finishing cattle diets without expecting negative effects on growth or meat quality. However, they should monitor cattle for signs of digestive upset and maintain adequate total fiber in the diet. The research suggests that finely chopped hay might help make feed more uniform and consistent, which can improve feeding efficiency. Confidence level: Moderate. The study was well-designed but limited to one hay type and one feeding period.
Beef cattle farmers and feedlot managers should pay attention to these findings, as they could affect feed processing decisions and costs. Cattle nutritionists can use this information when formulating diets. Farmers with limited access to longer-cut hay might find this research particularly relevant. However, farmers with cattle showing signs of digestive problems should consult with a veterinarian or nutritionist before making changes, as individual herds may respond differently.
Changes in cattle growth performance would be visible within 2 to 4 weeks of diet changes. Digestive adaptation typically occurs within 1 to 2 weeks. If farmers decide to switch to finely chopped hay, they should monitor cattle closely during the first 2 weeks for any signs of digestive upset, then continue monitoring throughout the feeding period.
Frequently Asked Questions
Does cutting hay finer affect how much beef cattle grow?
No, a 2026 study of 40 steers found that finely chopped hay (7.68 mm) produced the same growth rate and meat quality as longer-cut hay (11.54 mm), even though it reduced dietary fiber content by 1.9 percentage points.
Can farmers use finely chopped hay to make cattle feed more consistent?
Yes, research suggests finely chopped hay may improve feed uniformity without harming growth performance. However, farmers should monitor digestive health, as fiber digestibility was slightly reduced in cattle fed finely chopped hay.
Does finely chopped hay cause digestive problems in beef cattle?
This study found no major digestive problems with finely chopped hay (7.68 mm), though fiber digestibility was lower and fecal pH varied between groups. Farmers should still monitor cattle closely for signs of digestive upset.
How much time do cattle spend chewing finely chopped hay?
Cattle spent the same amount of time ruminating (chewing cud) whether fed finely chopped or longer-cut hay, which was unexpected since finely chopped feed typically requires less chewing effort.
What is the ideal hay particle size for finishing beef cattle?
This study suggests 7.68 mm finely chopped hay works as well as 11.54 mm longer-cut hay for growth and meat quality. The ideal size depends on balancing feed uniformity, digestive health, and cost, which farmers should discuss with a nutritionist.
Want to Apply This Research?
- Track daily feed intake and weight gain weekly for each pen of cattle. Record the date of any digestive issues (loose stool, reduced appetite, or other signs). Note the hay particle size being used and any changes made to the diet.
- If using an app to manage cattle nutrition, input the forage particle size for each diet batch and set reminders to observe cattle for signs of digestive health (normal manure consistency, normal appetite, normal chewing behavior) at least three times per week.
- Create a simple scoring system for digestive health (1 = excellent, 2 = good, 3 = fair, 4 = poor) and record scores weekly. Track average daily gain and feed efficiency monthly. If digestive scores decline or growth slows, consider adjusting forage particle size back to longer-cut hay and consult with a nutritionist.
This research describes findings from a controlled study of finishing beef cattle and should not be applied to individual animals without consulting a veterinarian or animal nutritionist. Results may vary based on cattle breed, age, health status, hay type, and overall diet composition. Farmers considering changes to forage particle size should monitor cattle closely for signs of digestive upset and maintain adequate total fiber in the diet. This article is for informational purposes and does not constitute veterinary or nutritional advice. Always consult with qualified professionals before making significant changes to cattle feeding programs.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.