DataGene’s December release of Australian Breeding Values (ABVs) includes the world-first Heat Tolerance ABV.
Australian dairy farmers are familiar with the impact of hot, humid weather on their herds. Now they can add breeding to their toolbox of ways to help cows handle the heat.
Dr Matt Shaffer, DataGene CEO, said that although environment and management conditions had a big impact on a cow’s response to the heat, genetics also played a role.
“Advances in genomics allowed the Dairy Bio team to identify gene markers for heat tolerance. The Heat Tolerance ABV allows farmers to identify animals with greater ability to tolerate hot weather with less impact on production,” he said. Dairy Bio is a joint initiative between the Victorian Government and Dairy Australia.
To breed for improved heat tolerance, look for bulls with a high Balanced Performance Index (BPI) and a Heat Tolerance ABV of greater than 100. Use a team of bulls to allow for the lower reliability.
The reliability of the Heat Tolerance ABV is 38% which is in line with the newer generation of genomic-only traits. Like all new ABVs, reliability is expected to improve with time, as more data becomes available.
Heat tolerance is favourably linked with fertility and unfavourably with production. This means a strong focus on heat tolerance bulls may improve fertility but compromise production.
“If breeding for heat tolerance, look for the exceptional animals that are strong for both BPI and heat tolerance,” he said.
While not all dairy farmers will want to include heat tolerance in their breeding priorities, some are keen to get started.