Why your genetics aren’t performing on farm
On paper, your herd might look strong. Good breeding decisions. High genetic indexes.
But on farm, the performance doesn’t always match.
Milk yield isn’t where it should be.
Fertility isn’t consistent.
Growth or condition isn’t quite right.
This is something we see regularly and it’s rarely down to the genetics themselves.
The Reality: Genetics Set Potential, Not Performance
Genetics determine what a cow can do. But whether that potential is actually achieved depends on everything around her.
That includes:
Nutrition
Fertility management
Cow health
Environment
If any of these are under pressure, genetic performance is limited.
Where Performance Is Usually Lost
In most herds, the issue comes down to a few key areas:
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Energy demand peaks, but intake doesn’t always match.
This creates a gap that affects:
milk yield
fertility
recovery
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Variation in forage quality or ration balance leads to inconsistent performance across the herd.
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Delayed cycling or poor conception rates reduce overall efficiency.
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Genetics selected without considering the farm system can lead to underperformance.
Why Two Similar Herds Perform Differently
It’s common to see herds with similar genetics delivering very different results.
The difference isn’t the breeding.
It’s how well the system supports those genetics.
What High-Performing Herds Do Differently
The most consistent herds don’t just focus on genetics.
They align:
Breeding decisions
Nutrition strategy
Herd management
This allows genetic potential to be fully expressed.
Final Thought
Genetics are a powerful tool but they don’t work in isolation.
If performance isn’t where it should be, the answer is rarely to “change the genetics”.
More often, it’s about understanding what’s limiting them.
If you want a second opinion on your herd performance or breeding direction, get in touch with JMC Genetics.
www.jmcgenetics.co.uk. info@jmcgenetics.co.uk