Bulls are becoming redundant with more and more farmers choosing to artificially inseminate their cows, says the Livestock Improvement Corporation (LIC).
LIC genetics general manager Peter Gatley said more dairy cows had been artificially inseminated in the 2007-2008 season than ever before.
This was the biggest increase since the service was first offered more than 50 years ago, he said.
Many farmers had chosen to use artificial insemination (AI) for their whole herds instead of a bull for some, with prices for cows bred by top AI sires exceeding $2000.
"Bulls are pretty much redundant for breeding replacements as farmers demand high Breeding Worth genetics which are only available from the top AI sires," he said.
"Farmers can access the top bulls in the world for less than $20 so having a bunch of bulls running amok in the herd is not particularly attractive. Some farmers won't have a bull on the property now."