According to Gram Research analysis, giving pregnant beef cows a protected soybean protein supplement during mid-pregnancy increases calf birth weight by about 3-4% and triggers beneficial changes in six muscle genes that control fat storage, energy use, and muscle growth, even though the calves catch up in weight by weaning. A 2026 study of 30 Zebu cattle found that calves from mothers receiving protected protein showed significantly higher expression of genes like ACACA, FASN, and IGF1R compared to calves from mothers receiving standard urea or regular protein supplements.
A new study shows that giving pregnant beef cows a special type of protein supplement during the middle of pregnancy helps their calves grow bigger before birth. Researchers found that calves born to mothers who received this protected protein had stronger muscle development and changes in genes that control how muscles work and grow. Interestingly, these benefits didn’t show up in how fast the calves grew after birth, but the changes in their muscle cells suggest long-term advantages. This research suggests that what pregnant cows eat can program their offspring’s bodies in ways that might help them later in life.
Key Statistics
A 2026 study of 30 beef cows found that calves born to mothers receiving protected soybean protein during mid-pregnancy weighed approximately 3-4% more at birth compared to calves from mothers receiving standard urea or regular protein supplements.
Calves from mothers receiving protected protein supplementation showed increased expression of six skeletal muscle genes (ACACA, FASN, PPARG, CPT2, IGF1R, and COL3A1) at 346 days of age compared to control calves, according to a 2026 research study of 30 beef cattle.
In a 2026 study of 30 Zebu cattle, the birth weight advantage from maternal protected protein supplementation (approximately 3-4% increase) disappeared by weaning time, suggesting the benefits are related to muscle gene programming rather than sustained growth differences.
A 2026 beef cattle study found that protected protein supplementation during maternal mid-gestation increased expression of ACACA, FABP4, PPARA, SCD1, COL3A1, and IGFR1 genes in offspring skeletal muscle compared to regular protein supplementation.
The Quick Take
- What they studied: Whether different types of protein supplements given to pregnant cows during the middle of pregnancy would affect how their calves grew and how their muscles developed.
- Who participated: Thirty pregnant beef cows (a breed called Zebu) that weighed about 532 kilograms each. The cows were divided into three groups that received different types of nutrition from about 4 to 7 months of pregnancy.
- Key finding: Calves born to mothers who received protected soybean protein were about 3-4% heavier at birth than calves from mothers who got standard urea or regular protein supplements. More importantly, these calves showed increased activity in six different muscle genes that control fat storage, energy use, and muscle growth.
- What it means for you: For cattle farmers, this suggests that investing in better protein supplements for pregnant cows might improve the quality of their offspring’s muscles, even if it doesn’t immediately show up as faster growth. The changes in muscle genes could mean better meat quality or performance later. However, this was a small study in one breed of cattle, so more research is needed before making major feeding changes.
The Research Details
Researchers divided 30 pregnant beef cows into three equal groups of 10 cows each. From about 4 months to 7 months of pregnancy, each group received different types of nutrition: one group got a basic diet with simple urea (a cheap nitrogen source), another got a commercial protein supplement that breaks down quickly in the cow’s stomach, and the third group got protected soybean meal that breaks down slowly in the cow’s stomach. After the supplementation period ended, all cows were managed together on pasture until they gave birth. The researchers then tracked the calves from birth through weaning and into a 60-day feedlot period, measuring their growth, muscle development, and gene activity.
This research approach matters because it tests whether the timing and type of nutrition during pregnancy can create lasting changes in how an animal’s muscles are programmed to work. By measuring gene expression (which genes are turned on or off), the researchers could see changes that might not show up immediately in growth but could affect the animal’s performance, meat quality, or health later in life. This is important because it shows that nutrition during pregnancy might have long-lasting effects beyond just birth weight.
This study was a controlled experiment with random assignment of treatments, which is a strong research design. However, the sample size was relatively small (only 10 cows per group), which means the results might not apply to all cattle breeds or conditions. The study was conducted in one location with one breed of cattle, so results might differ in other settings. The researchers measured many different outcomes, which strengthens the findings but also means some results could have occurred by chance. The fact that birth weight differences were modest (about 3-4%) but gene expression changes were clear suggests the genetic changes are real and important.
What the Results Show
Calves born to mothers receiving protected soybean protein (RUP group) weighed about 3-4% more at birth compared to the other two groups. This difference was statistically significant, meaning it’s unlikely to have happened by chance. Interestingly, this birth weight advantage disappeared by weaning time—all calves caught up to similar weights regardless of their mother’s diet during pregnancy. Even more interesting, the calves from the protected protein group showed increased activity in six different genes in their skeletal muscles at about 11.5 months of age. These genes control important functions like fat storage (ACACA, FASN, SCD1), energy burning (PPARA, CPT2), muscle growth (IGF1R), and muscle structure (COL3A1). The protected protein group also showed higher expression of FABP4, which helps muscles use fats for energy. These gene expression changes were significantly higher in the protected protein group compared to both the control group and the regular protein group.
The study found no differences between groups in weaning weight, daily growth rates, or how much the calves ate. Muscle fiber number and structure looked the same across all groups. The calves’ ability to digest food was similar regardless of maternal diet. Their eating behavior and body composition measured by ultrasound were also not different. This suggests that while the protected protein created important changes at the genetic level in muscle cells, these changes didn’t immediately translate into faster growth or bigger muscles that could be measured by standard methods. The lack of differences in digestibility and eating behavior suggests the calves’ basic metabolism and appetite weren’t altered by the maternal diet.
This research adds to a growing body of evidence showing that nutrition during pregnancy can program an animal’s development in ways that show up later as changes in gene activity, even when immediate growth isn’t affected. Previous studies have shown similar “programming” effects with other nutrients. This study is unique because it specifically compares two different types of protein (one that breaks down quickly in the stomach versus one that breaks down slowly) and shows that the slow-breaking type has more benefit. The finding that birth weight increased but later growth didn’t differ is consistent with some previous research suggesting that fetal programming affects quality more than quantity of growth.
The study used only 30 cows total (10 per group), which is a small sample size. Results might be different with larger numbers or different breeds of cattle. The study was conducted in one location with one breed (Zebu cattle), so the findings might not apply to other cattle breeds or environments. The researchers only measured gene expression at one time point (about 11.5 months of age), so they don’t know if these gene changes persist longer or when they first appear. The study didn’t measure actual muscle quality, meat characteristics, or long-term performance, so it’s unclear if the gene changes translate to practical benefits. The study was relatively short-term, following calves only through the backgrounding phase, so long-term effects are unknown.
The Bottom Line
For cattle producers: Consider using protected protein supplements during mid-pregnancy if cost-effective, as evidence suggests potential benefits to offspring muscle development. However, this is based on one small study, so consult with a nutritionist before making major feeding changes. The current evidence is moderate—the birth weight increase and gene expression changes are real, but practical benefits haven’t been proven yet. For researchers: This study provides preliminary evidence supporting further investigation into protein type during pregnancy, with larger sample sizes and longer follow-up periods.
Beef cattle producers and nutritionists should be interested in these findings, particularly those focused on improving meat quality or offspring performance. Veterinarians advising on pregnant cow nutrition might find this useful. Researchers studying fetal programming and nutrition would find this relevant. This research is less relevant to dairy farmers, other livestock producers, or people not involved in cattle production, though the underlying principles might apply more broadly.
The birth weight increase appeared by the end of pregnancy (about 3 weeks after supplementation ended). The gene expression changes were measured at about 11.5 months of age, suggesting these adaptations persist for months after birth. It’s unknown how long these changes last or when they might translate into measurable differences in meat quality or performance. Practical benefits might take several months or longer to become apparent.
Frequently Asked Questions
Does what a pregnant cow eats affect her calf’s muscle development?
Research shows that maternal nutrition during mid-pregnancy can program offspring muscle development at the genetic level. A 2026 study found that calves from mothers receiving protected protein supplements had increased expression of six muscle genes controlling fat storage and growth, even though growth rates were similar after birth.
What type of protein is best for pregnant beef cows?
A 2026 study comparing three protein strategies found that protected soybean protein (which breaks down slowly in the stomach) produced better results than standard urea or regular protein supplements, increasing calf birth weight by 3-4% and enhancing muscle gene expression.
When during pregnancy should cows receive protein supplements?
The 2026 research provided supplements from approximately 4 to 7 months of pregnancy (mid-gestation) and found this timing produced increased birth weight and beneficial muscle gene changes. The optimal timing for other breeds or conditions may differ.
Will better nutrition during pregnancy make calves grow faster after birth?
Not necessarily. A 2026 study found that while protected protein supplementation increased birth weight and muscle gene expression, calves caught up to similar weights by weaning regardless of maternal diet, suggesting benefits relate to muscle quality rather than growth rate.
How long do the muscle gene changes from maternal nutrition last?
A 2026 study measured gene expression at 11.5 months of age and found the changes persisted, but research hasn’t determined how long these adaptations last or whether they eventually affect meat quality or performance.
Want to Apply This Research?
- For cattle producers using the app: Track pregnant cow body weight weekly during mid-gestation, supplementation type and amount, and calf birth weights. Compare these metrics across different supplementation strategies to monitor if you see similar birth weight increases in your herd.
- Implement a feeding protocol where pregnant cows receive protected protein supplements from 4-7 months of gestation, and use the app to log supplementation dates, types, and costs. Set reminders for supplementation timing and track which cows received which treatments to correlate with offspring outcomes.
- Create a long-term tracking system that records: (1) maternal supplementation details during pregnancy, (2) calf birth weight and weaning weight, (3) growth rates through backgrounding phase, and (4) eventual carcass quality metrics if available. Compare these across different supplementation strategies over multiple breeding seasons to determine if the gene expression benefits translate to practical improvements in your operation.
This article summarizes research on beef cattle nutrition and is intended for educational purposes only. The findings apply specifically to beef cattle during pregnancy and may not apply to other species, life stages, or production systems. Farmers and ranchers should consult with a veterinarian or animal nutritionist before making changes to feeding programs, as individual herd conditions, available resources, and economic factors vary. This research represents preliminary findings from a single study with a small sample size; larger studies are needed to confirm practical benefits. The gene expression changes observed do not guarantee improvements in meat quality, growth performance, or other economically important traits. Always follow label directions for any supplements or feed additives used.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.