Available for all breeds, the sire stillbirth and maternal stillbirth ABVs give dairy farmers a breeding tool to reduce stillbirths.
Between 5-7 per cent of Australian dairy calves are stillborn or die within the first day.
Stillbirth is the leading cause of death in Australian dairy calves – more than double scours and respiratory disease combined.
Internationally, stillbirth rates as high as 10 per cent have been reported.
Cows and bulls will each receive two ABVs: sire stillbirth and maternal stillbirth.
The sire stillbirth ABV predicts the percentage of progeny that are born dead, while the maternal stillbirth ABV predicts the percentage of calvings that result in a dead calf.
Both calf and cow have a role in a successful calving.
From a breeding perspective, it is important to breed for calves that are born alive and cows that give birth to a live calf.
While many environmental factors contribute to the risk of stillbirth, genetics also play a role.
Research conducted by Dr Michelle Axford as part of her PhD studies showed there is enough genetic variation between animals within a breed to enable selection for a lower risk of stillbirth.
This indicates genetic improvement is achievable through sustained selection.
To breed for fewer stillbirths, farmers should select animals with stillbirth ABVs less than zero.
Most Holstein and Jersey bulls fall between -2 per cent to +2 per cent for Stillbirth ABVs. The best bulls are below -5 per cent for stillbirth ABVs.
Stillbirth ABVs are published in the Good Bulls App, DataVat, and heifer genomic results.
The reliability of the sire stillbirth ABV in a young genomic Holstein bull is about 60 per cent, similar to the reliability of the ABVs for fertility and overall type. The reliability of maternal stillbirth is about 52 per cent.
While the benefits of lowering stillbirths are clear for calf welfare, there are additional welfare and productivity benefits arising from lower maternal stillbirth rates.
Studies have reported that cows experiencing stillbirths show reduced pregnancy rate, increased days open, and lower milk yield early in the first lactation.
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