Gram Research analysis of 22 Kazakh mares identified six key genes and specific body measurements linked to milk production. Mares with longer bodies and larger teats produced significantly more milk, while high-producing mares showed different energy-use patterns in their blood involving genes like PMP22 and AGPAT4. These findings suggest that selecting breeding animals based on physical traits and understanding their metabolic differences could improve milk production in this hardy desert-adapted breed.
Researchers studied 22 Kazakh mares to understand why some produce more milk than others. By analyzing blood samples and using computer learning, they discovered specific genes and body chemicals linked to milk production and fat content. The study found that mares with longer bodies and larger teats tend to produce more milk. Six key genes were identified that affect how the body uses energy for milk production. These findings could help farmers breed healthier, more productive mares in harsh desert environments where these horses naturally thrive.
Key Statistics
A 2026 research study of 22 Kazakh mares identified 286 differentially expressed genes when comparing high-yield versus low-yield milk producers, with six candidate genes (PMP22, FAM83A, HSD17B3, AGPAT4, SLC50A1, and ERBB3) showing strong associations with lactation performance.
According to research reviewed by Gram, milk yield in Kazakh mares was significantly correlated with body length, teat diameter, and teat length, suggesting that physical measurements can predict milk production capacity in this breed.
A 2026 analysis of 22 Kazakh mares found that high-producing mares showed enriched metabolic pathways related to the tricarboxylic acid cycle, indicating altered energy metabolism involving carbohydrates, lipids, and amino acids compared to low-producing animals.
Machine learning analysis of blood samples from 22 Kazakh mares identified GLDC as a candidate gene potentially associated with milk fat percentage, possibly through its connection to the amino acid histidine, though this relationship requires further validation.
The Quick Take
- What they studied: Which genes and body chemicals in Kazakh mares are connected to how much milk they produce and how much fat is in that milk
- Who participated: 22 Kazakh mares (a horse breed from Central Asia) tracked over a 105-day milking period, with measurements of milk amount, milk quality, and body measurements
- Key finding: Six specific genes were linked to milk production, and mares with longer bodies and larger teats produced significantly more milk. High-producing mares showed different energy-use patterns in their blood
- What it means for you: If you raise Kazakh mares, this research suggests selecting for body length and teat size could improve milk production. However, this is early-stage research on a small group, so results need confirmation in larger studies before making breeding decisions
The Research Details
Scientists collected blood samples from 22 Kazakh mares and measured their milk production daily for 105 days (about 3.5 months). They recorded 15 different traits including how much milk each mare produced, the milk’s fat content, and physical measurements like body length and teat size. They then used advanced laboratory techniques to identify which genes were active in the blood of high-producing versus low-producing mares, and which genes were active in mares producing high-fat versus low-fat milk.
The researchers used two main approaches: first, they compared gene activity between high and low producers (finding 286 different genes), then between high-fat and low-fat milk producers (finding 627 different genes). They also measured various body chemicals (metabolites) in the blood to understand how the mares’ bodies were using energy differently. Finally, they used artificial intelligence and machine learning to identify which genes were most important for predicting milk fat percentage.
This approach is important because it combines multiple types of information—genes, body chemistry, and physical traits—to paint a complete picture of what makes some mares better milk producers. Using blood samples is practical because farmers can collect them easily without stressing the animals. Machine learning helps identify patterns that humans might miss when looking at thousands of genes at once.
This is a preliminary study with a small sample size (22 mares), which means results should be viewed as starting points rather than definitive answers. The study was well-designed with proper statistical methods, but the findings need to be tested in larger groups of mares to confirm they’re reliable. The research was published in a respected scientific journal (BMC Genomics), which suggests it passed quality review, but the authors themselves note that some findings ‘require further validation.’
What the Results Show
The study identified six key genes (PMP22, FAM83A, HSD17B3, AGPAT4, SLC50A1, and ERBB3) that appear connected to milk production in Kazakh mares. These genes are involved in how the body processes energy and builds fats, which makes sense because milk production requires lots of energy and fat.
Physical measurements mattered too: mares with longer bodies, larger teats, and longer teats produced significantly more milk. This suggests that selecting breeding animals based on these physical traits could improve milk production.
When researchers looked at the blood chemistry of high-producing mares, they found these animals had different patterns of energy use. Specifically, high-producing mares showed more activity in pathways related to the TCA cycle (a fundamental energy-production system in cells). This suggests their bodies are more efficient at converting food into milk.
The study also identified specific body chemicals (glycerone, glucose, galactose, glycerol, histidine, and anserine) that were present in different amounts in high versus low producers, indicating different metabolic patterns.
A machine learning analysis highlighted one gene called GLDC as potentially important for milk fat percentage, possibly through its connection to an amino acid called histidine. However, the researchers emphasize this finding needs more testing. The study also confirmed that milk yield and milk composition are controlled by multiple genes working together, not just one or two genes—which is typical for complex traits in animals.
This study builds on previous research showing that milk production in livestock is influenced by both genes and body characteristics. The specific genes identified here haven’t been extensively studied in mares before, making this research novel for the Kazakh breed. The findings align with general knowledge about how mammalian bodies produce milk (requiring energy, fat metabolism, and specific proteins), but provide new breed-specific information.
The biggest limitation is the small sample size—22 mares is enough to identify patterns but not enough to be completely certain those patterns apply to all Kazakh mares. The study only looked at one breed in one region, so results may not apply to other horse breeds. Some of the genes identified need further testing to confirm they actually affect milk production. The study was observational (watching what happens naturally) rather than experimental (testing specific interventions), so it shows associations but not definitive cause-and-effect relationships.
The Bottom Line
For Kazakh mare breeders: Consider selecting breeding animals based on body length and teat measurements, as these traits correlated with higher milk production. However, confidence in this recommendation is moderate because the study is small and preliminary. For researchers: These six genes and metabolic pathways warrant further investigation in larger populations. For nutritionists: The metabolic differences in high-producing mares suggest they may benefit from diets optimized for energy and fat metabolism, though this needs testing.
Kazakh mare breeders and farmers in Central Asia and similar climates should find this most relevant. Researchers studying livestock genetics and milk production will find value in the methodology and candidate genes. Horse nutritionists might use this to develop better feeding strategies. This research is less directly applicable to other horse breeds or cattle until similar studies are done in those species.
If breeders begin selecting for the physical traits identified (body length, teat size), improvements in milk production could appear within 2-3 generations (roughly 6-9 years for horses). Genetic improvements from selecting based on the identified genes would take longer—likely 5+ years—and would require genetic testing technology to become more accessible and affordable.
Frequently Asked Questions
What genes affect how much milk a mare produces?
Six genes were identified: PMP22, FAM83A, HSD17B3, AGPAT4, SLC50A1, and ERBB3. These genes control energy use and fat metabolism, which are essential for milk production. However, this finding comes from a small study of 22 mares and needs confirmation in larger groups.
Can you predict milk production by looking at a mare’s body?
Yes, according to this research. Mares with longer bodies and larger teats produced significantly more milk. These physical traits could help farmers identify which young mares will become good milk producers, though the study is preliminary.
How do high-producing mares use energy differently?
High-producing mares showed increased activity in the TCA cycle, a cellular energy-production system. Their blood also contained different levels of body chemicals like glucose and glycerol, suggesting their bodies are optimized for converting food into milk more efficiently.
Can these findings apply to other horse breeds?
This study focused specifically on Kazakh mares, so results may not directly apply to other breeds. Similar research would need to be conducted in other horse populations to confirm whether these genes and traits matter equally across different breeds.
How soon could farmers see improvements from using this research?
Selecting mares based on physical traits (body length, teat size) could show results in 2-3 generations (6-9 years). Using genetic information would take longer—likely 5+ years—and would require genetic testing to become more accessible and affordable.
Want to Apply This Research?
- Track mare body measurements monthly (body length, teat diameter, teat length) alongside milk production volume and fat percentage. Create a simple scoring system: mares scoring high on physical traits should be monitored for milk output to validate the research findings in your own herd.
- Use the app to record which mares have the physical characteristics linked to higher milk production (longer body, larger teats), then prioritize these animals for breeding. Set reminders to measure new foals for these traits as they grow to identify future high producers early.
- Over 2-3 years, track whether mares with the identified physical traits consistently produce more milk and higher-fat milk. Compare your herd’s results to the research findings. If patterns match, use this information to guide breeding decisions. If patterns differ, document why—this helps understand how local conditions affect the research findings.
This research is preliminary and based on a small sample of 22 mares. The findings have not yet been confirmed in larger populations or other horse breeds. Farmers should not make major breeding decisions based solely on this study. Consult with veterinarians and animal geneticists before implementing breeding strategies. The identified genes and metabolites require further validation before clinical or breeding applications. This article is for informational purposes and should not replace professional veterinary or breeding advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.