Semen shake up: What leading studs want as fertility indicators (2025)

Seedstock breeders across the country are split on which fertility tests are the best reflection of a bull's long-term fertility potential, but agree one test alone isn't enough.

Many multi-vendor sales follow the Australian Cattle Vets' bull breeding soundness evaluation which requires bulls to complete a mandatory crush-side motility semen test.

If the animal only reaches a qualifying level of 30 to 59pc, it is subject to a morphology test, which, either voluntary or forced, must result in the bull passing, or it will be withdrawn.

While this is standard practice, it is this risk that can put some stud principals off the idea.

It then becomes a challenge to enforce consistency, particularly at on-property sales, where vendors set their own parameters.

Renowned central Queensland Droughtmaster breeders Mac and Gayle Shann propose allowing bulls with lower morphology percentages to be sold with guarantees at multi-vendor national sales.

Further south, Sally White, Eastern Plains Angus, Guyra, believes so strongly in morphology testing that she wants to see it become a mandatory test at all live auctions.

The Shanns of Lamont Droughtmasters and Charmasters, Cantaur Park, Clermont sell their bulls at MAGS in Charters Towers and the Droughtmaster National Sale.

At MAGS, bulls with low morphology results are sold with a two-year improvement guarantee.

It is possible for Q-level bulls to be fertile, especially in natural, multi-sire matings, and Ms Shann said they had very few issues post-sale.

"(Our bulls) are tested both for crush side motility and morphology on that one day, which is not always a fair or accurate method, particularly on young bulls," she said.

"We are glad to say we have very few issues with bulls post-sale, which we put down to allowing our bulls to live a low maintenance life out on grass only leading up to coming into their sale prep, which we believe stands them and their fertility in good stead for their adult lives.

"We focus a lot on our bull's sheaths and testicular structure as we believe these attributes cause bull failure more than semen quality.

"Physical confirmation and temperament also add to the future potential of the bull as a sire."

The Shanns argue that semen tests only capture a bull's fertility on a specific day, and they believe that these tests do not fully reflect a bull's long-term fertility potential.

"With large numbers of bulls, it's not possible for them to be tested on the job," Ms Shann said.

"We test for both motility and morphology, but that's just one snapshot in time, and it's not always an accurate reflection of a bull's true fertility.

"Our vet also believes it is very tough on young bulls to determine their future on one test that day.

"Therefore, some vendors are reluctant to go ahead with the morphology testing at National Sales as it can wipe out numerous bulls when the issues are not inherent or dire, and the particular problems are issues that will rectify themselves."

The Shanns believe better quality bulls could be sold if guarantees were offered with their lower morphology results.

"We have conducted a few trials ourselves with changing environmental factors and what they do to their morphology result, and it's quite incredible," Ms Shann said.

"So when you consider weather, seasons, a bout of three-day sickness, any stress or infection in the body, these things can all send the morphology reading south until they have recovered from the cause.

"I would also like to see unsound bulls withdraw for structural issues such as skeletal structure, loose sheathes and testicular issues as it gives the breed a bad name when these attributes are presented in sires."

Ms White doesn't believe in basing a bull's fertility on only one test and backs morphology semen tests as a much more thorough measure of fertility than motility alone.

According to Ms White, while motility tests can indicate whether sperm is moving, they don't necessarily guarantee fertility.

"You can't definitively say a bull is fertile based on one test," she said.

Ms White said if seedstock producers were more committed to the integrity of their bulls, they would have no hesitation in doing fertility testing.

"The biggest cost for seedstock producers isn't the semen test itself - it's the loss of bulls from the sale team if they fail," she said.

"That's why many breeders shy away from pre-sale testing-they don't want to pull bulls out of their sale draft."

Ms White said the current state of semen testing had led to a lack of consistency in the industry, with buyers often paying a premium for bulls that might not be fully proven.

"If you're buying a bull at a sale, you should expect that it has a high probability of being fertile," Ms White said.

"The vendor should be shouldering the majority of the risk, not the buyer."

She supports more rigorous testing and transparency in the industry and for more widespread use of accredited testing services such as Bullcheck.