The value of focusing on joining weights for first calf cows has been well proven in the Girl Power Project, which is winding up in central and western Queensland after four years of collecting data.
The project has been a Meat & Livestock Australia Producer Demonstration Site, part of a program to improve livestock production across the nation through on-property trials.
Getting young female cattle to joining weights of 350 kilograms in the northern rangelands is one of the outcomes it worked towards.
It began with 12 participants and concluded with seven operations collecting data.
Project officer Ed Wood, with the Central Highlands Regional Resource Group, said that in the majority of cases, they had achieved the conception rates they'd aimed for.
He was presenting at a field day at Stratford Station situated at the bottom end of the Desert Uplands, north of Blackall, whose owner, Robyn Adams has been one of the driving forces of the project.
One question the project asked was whether joining could take place at 15 months, which in many of the land types involved in the project would mean boosting nutrition.
"It's easy to get a well-grown maiden heifer in calf if you understand the critical mating weight for your property, and know what to do to get to that weight," Mr Wood said.
"The rule of thumb is that unless you're doing 150 kilogram liveweight gain a year in your steers, you can't join at 15 months, consistently.
"Some in the project were close to doing it - we had people with 350-400kg joining weights, but there is a flag - if you're dropping back with your rolling (rainfall) averages, what will happen then."
Most participants experienced a good run of seasons throughout the trial, and so the project didn't identify how they'd address that, but Mr Wood said production feeding would be a consideration.
Outcomes emphasised the importance of supporting heifers from weaning to having their second calf, to set them up well enough to become strong, consistent breeders.
In drier times in the northern rangelands, weight loss through mothering on an already smaller frame can eventuate in failure to reconceive, and death.
Because the land types mean energy and protein can be inadequate for young females with high demands on under-developed physiologies, conversation among the 40 field day attendees looked at options such as having more waters, supplementation, resting paddocks and pasture improvement over time.
"During the post-field day barbecue, participants were still talking about what the GPP data showed regarding significant weight loss in maiden cows, then again having that second calf, and not getting to mature weights until near five years of age, if they are successful in conceiving and raising those first two calves, with that initial join at two years," Ms Adams said.
"They realised that these younger girls are a large percentage of their herd.
"So the discussion followed through to early weaning options to save these novice mothers from slipping too far, and ways to work on improving native pastures all year round rather than just waiting for the good seasons, so there's better nutrition in some pastures for these young breeders to go onto.
"Then came the conversations on what lick/supplementation would be best for these windows of opportunity, to arrest and to further rebuild and grow."
Mr Wood said forage budgets were an important part of the project, and monitoring sites set up 20 years ago on Stratford as part of a Long Term Carrying Capacity project were visited.
Department of Agriculture senior scientist Paul Jones, based in Emerald, was on hand with land condition reports that gave insights into how pastures at Stratford had changed.
It was this that most impressed Blackall producer Liz Allen, also a member of the western Queensland committee of the Northern Australia Beef Research Council, from which Girl Power was conceived.
"A key learning for me is to go back to the Long Paddock internet site to look at its latest forage data and download maps," she said. "The day reinforced the need to set up pasture monitoring sites."
Ms Allen said the way the project had continued to raise awareness of the importance of looking after second calf cows was invaluable.
Fellow NABRC committee member Sue George came up from Jundah for the day, saying it showed the Girl Power aims of improving calving rates of first calf cows had definitely been fulfilled.
"Take homes for me were reinforcing basics such as supplementation, bull selection, vaccination and the like," she said.
"There's such a struggle with adoption for all these things but the day showed how important they were.
"The day also showed you can never have too much data."
Mr Wood said that as the data was crunched, it was looking like there would be a number of unexpected outcomes, for example, not having any production or health issues to contend with.
"There were no real seasonal issues to contend with - everyone could match carrying capacity to grass availability," he said.
One of the findings was that the producers that stayed in the trial generally had more labour at their disposal, highlighting staffing issues.
"It's not easy to collect crushside data while you're preg testing, with minimal staff," Mr Wood said.