What is a phantom cow?
It’s a cow that has been mated and didn’t return to heat, but did not conceive to that mating. Phantom cows cost dairy farming systems as they either become pregnant much later in the mating period or end up empty. The prevalence of these cows has been estimated as high as 9% in some herds.
Can anything be done about them?
Phantom cows can be detected through early age scanning of all cows who have been mated but not returned to heat. They will either be pregnant or a phantom. Identified phantoms can be treated by enrolling in a CIDR program with fixed time AI.
Is there local data around this?
We have done an analysis from seven farms with wearable collars who did an early age scan and intervention to their phantom cows this season.
There were 228 phantom cows in total, with a 5% prevalence average across the farms (the range was 4-9%).
Key findings from these phantom cows:
19% had no heat events at all before mating, i.e. were mated at their first heat and then became a phantom cow.
9% had been treated for metritis with Metri-Clean.
28% had been treated as non-cyclers with a CIDR program at their first mating.
Of the phantom cows, 17% were 2 years old, 14% were 3 years old, 59% were 4-8 years old, and 10% were 9+ years old.
Cows that went on to become phantoms on average ruminated lower in the colostrum period than the rest of the herd (there was some farm variation around this).
62% of phantoms that ended up empty did have another heat after their intervention mating. Unfortunately for most of these cows, mating had finished by then, so they didn’t get another chance at breeding – but the intervention did seem to have ‘restarted’ their cycle.
Pregnancy outcomes after intervention mating of these cows:
47% pregnant,
49% empty,
3% recheck,
1% dead.
What are the takeaways?
Phantom cows are present in every dairy herd, but they are more likely if you’ve treated a high number of non-cyclers.
Heifers and middle-aged cows are most at risk of becoming phantoms.
It’s interesting that cows who became phantoms generally ruminated less during the colostrum period. This reinforces that focusing on transition management is key to setting you up for a good start to the season.
Almost half of phantom cows became pregnant following treatment, which would make scanning and intervention cost-effective on most farms.
If you’re interested in an early age scan for phantom cows next season, discuss this with your KeyVet to work out the logistics, such as optimum timing and treatment options.
