When faced with rapidly deteriorating seasonal conditions from 2017 to 2018 - and then another dry year in 2019 - the pair implemented a process involving raw data scans of all females to determine which breeders to retain.

This included collecting and analysing data at 12 months of age from weighing animals and ultrasounds of eye muscle area and intramuscular, rib and rump fat scores.

"This guided our heifer selection, along with a thorough review of structural soundness," Mr Thompson said.

"We have now been using this process for four years in an effort to best protect the investments made into improving our cattle genetics across many years."

Typically, the Thompsons run a pure Angus herd with 650 to 800 breeders on their 2500-hectare property, Belang. They undertake opportunity cropping in conducive seasons, but cattle are the main enterprise.

Mr Thompson said the prolonged drought was unprecedented in the 40 years his family had farmed in the area.

"It started in 2017, when rainfall was well below average and the timing of the rain that we did get just didn't stack-up," he said.

"We battled through and decided we would use the drought that year as a selection and culling opportunity.

"We sold all of our oldest cows."

Mr Thompson said the season in 2018 was just as bad and they culled more heavily all of their under-performing females.

"This was based on whether they were pregnant after a seven-week joining period, or if they had any conformation issues or visible defects," he said.

"We were then able to have lower stock numbers, and be in a position of being able to feed and keep the best quality breeders we had in the herd. We also wanted a shorter joining period so we would have a tight calving."

The female culling continued in 2019, based on the heifer raw data scan and progeny assessment process devised by the Thompsons.

So, to the start of 2020, the pair had cut female numbers from 800 head joined in 2016 to 350 head joined.

Sales of cull stock were used to fund the cost of buying-in feed during the drought.

This was mostly hay, pellets and grain, which needed to be trucked-in from as far afield as Western Australia and South Australia as the drought's bite deepened and east coast fodder supplies tightened.

"Throughout this horrendous period, we were always committed to keeping our cattle enterprise going because we didn't want to lose all our long-term efforts in making genetic gains," he said.

"By funding supplementary feed with sales of cull stock, we were able to keep the herd base in good condition."

The Thompson's beef operation is set-up for the long-fed grain market, with all steers and cull heifers raised on pasture, backgrounded on oats and then turned-off to feedlots at about 12 to 15 months old - when at liveweights of about 480 kilograms.

Joining occurs from October to December, calving starts in July and progeny are weaned in March-April.

A long-term focus on improving the female breeding stock has resulted in average pregnancy rates of 95 to 98 per cent and calving rates of 98pc.

Aside from calving ease and birthweight, other key genetic selection traits include Estimated Breeding Values for 600-day growth, positive fat and positive intramuscular fat.

"We want our steers to be achieving winter and spring growth rates of about 1.6kg per head per day," Mr Thompson said.

"These are sold directly to a range of major east coast feedlots, including Caroona (JBS), Rangers Valley (at Glen Innes) and Whyalla (at Texas), and we typically get an Angus premium through all of them."

The Thompsons have been using the Brazier family's Choice Angus stud, based at Molong, for about 10 years and their herd is tracking at similar rates of genetic improvement in key profit-driving traits.

Mr Thompson said while they were now in a herd re-building phase, they would continue to focus on strict selection of females to avoid undoing all the work done and investments made during the drought years.

He said this would likely mean continuing to cull the lowest performing 2-5pc of breeders, despite already being at a low stock numbers.

"Our aims are to keep lifting the productivity of the overall cattle enterprise, produce a highly valuable and saleable carcase and enticing buyers back time-after-time," he said.

"We don't get rewarded on our carcase traits at the moment, but I have a strong feeling there will be premiums for carcase values in the near future.

"We are also starting to breed some bulls for our own use as part of a strategy to contain costs and boost profits per hectare.

"The three drought years have prompted us to take a much closer look at our whole business and how we can best move it forward."

Part of this strategic planning is continuing to improve pastures on their medium rainfall zone property, using tropical species such as Bambatsi.

About 70ha of land typically used for forage crop production for background feeding was this year put down to a mix of oats and vetch to replenish empty silage pits for drought feed.

Another 53ha was sown to an opportunity canola crop because the seasonal conditions had turned around so remarkably. This yielded 3.8 tonnes/ha at harvest.

On the further forecast of a higher than average rainfall for summer, the Thompsons decided to sow 70ha of sorghum for an opportunity cash crop.

"We have been able to go down this path because we had such welcome rainfall in February and March 2020 and a good winter, with great pasture growth," he said.

"This year has been a real relief-valve after such a shocking dry period, although, we are well aware there are still a lot of dry pockets in many parts of Australia."