Are empty second-calvers the most costly animal on your property?

on 28th August 2025

Reproductive performance remains the single most important driver of profitability in commercial breeding herds, according to veterinarian Ian Croft, who addressed the topic at the Gyranda open day ‘all about the cow’ session.

Mr Croft, who works extensively with commercial and stud operations across Queensland, outlined the critical performance indicators that determine whether a herd is operating efficiently: conception rates, branding rates, weaning rates, and age structure.

He stressed that empty females, particularly empty second-calvers, are the most costly animals on a property.

“They’ve had every input cost put into them… all the vaccinations, management, and feed, and yet they aren’t producing a calf,” he said.

He warned they also “miss the best sale windows”, making them even more expensive to keep.

Mr Croft encouraged producers to “keep a young cow herd and constantly improve your genetics”, noting that “older cows, especially in harder country, have a significant drop in performance after about 10 years of age.”

When it came to replacements, he said the key decision was when to start them breeding – and that depends on hitting critical weight targets.

“You’ve got to know your mature cow weight,” he said.

“In Bos indicus and composite herds, you need heifers to be 65 per cent of that [mature cow] weight before joining.

“If they’re too light, your conception rate goes down, and the ones that do get in calf often take longer to get back in calf.”

Mr Croft presented joining comparisons from commercial herds.

“When we join at two years of age, conception rates are generally above 90pc,” he said.

“With yearling joinings, in a good herd you might get 85pc in calf, but losses from pregnancy to calving and getting second-calvers back in calf are much higher.”

In one example, by six years of age, “only 43pc of the original yearling-joined cohort remained, producing around 251 calves”.

For the same herd joining at two years, “66pc of the original cows were still there at six years of age, producing about 265 calves, even though they’d had one fewer joining in their lifetime.”

“The moment a heifer or a cow drops out of the herd at a young age, that loss is magnified over the years,” he said.

“Extended joinings create a long tail of late-calving heifers, many of which will end up empty as second-calvers.”

His advice: join more than you need, join for a short period, and sell the empties early while they’re still in good condition.

“There’s no problem with an empty heifer at the end of joining… there’s a big problem with an empty second-calver,” Mr Croft said.

Mr Croft stressed preg-testing, early bull checks, and reproductive disease testing.

“Pestivirus and vibrio can cost you a lot if you’re not monitoring for them,” he said.

Body condition was another major factor.

“Early weaning is a low-cost way to get more cows back in calf – it lifts their condition through winter and into joining,” he said.

In phosphorus-deficient country, he said supplementation was non-negotiable.

“Without phosphorus, lactating cows lose too much weight, and your heifers won’t grow out to joining weight,” he said.

He also recognised that some producers can successfully join yearlings.

“They’ve got to have the feedbase, genetics, and management to make it work,” he said.

“For others, you’re better off waiting until those heifers are heavier and more mature.

“The long-term productivity is often better.”

He urged producers to “run the numbers on your own herd” rather than relying on assumptions.

“If you think you’re getting more calves out of joining younger, put it in a spreadsheet and see what you’re really averaging,” he said.

Gyranda stud principal Peter Mahony said it was a fantastic informative session with a great presentation on the long-term implications of when you decide to join your females.

“The key is getting those first-calfers back in calf, and sometimes holding them til they’re of weight is what you have to do,” he said.

For young Brangus breeder and Dawson Catchment Coordination Association employee, Abigail Johnson from Dululu, she said it was eye-opening and somewhat contradictory to what she had heard previously.

“It was really interesting to see the data that he had showing that yearling mating can actually cost you in the long run,” she said.

“Ian did say that yearling mating was still optimal, but he also highlighted how that head start can be detrimental to your herd in the long run.”

(article by Bella Hanson p.14 Queensland Country Life, 22 Aug 2025)