There is no such thing as a roundup. When there is no natural water available, the bulk of the cattle in any one of the large paddocks served by the water yard can be gathered within 24 hours. There are 30 of these water yard and trap systems on the 700-square mile station. The largest one has 120 square miles of grazing area feeding into it. Like most of the cattle operations in this part of Australia, there is no set breeding season.
Bulls stay with the cows year around.
In good years cows will calve every 10 months or so, but in dry years when feed is in short supply, cows won't recycle and breed nearly so quickly. It's better to let the cattle work it out themselves. Approximately four bulls are run per 100 cows. They stay with the herd until they die from injury or are culled because of age or infirmity. Maybe 90 or 100.