Wanted: Males, ready to work

Before you go and visit a stud or pick up a bid card, I recommend you start your bull buying process at home. Take a moment to look at how your herd is performing.

What bull joining percentage have you been using? The larger your paddocks and the less reliable your bulls, the more you may need. Conversely, with smaller paddocks, controlled waters and using tested bulls, you can get away with fewer. Do you have paddocks suitable for joining you can select?

How have your preg test, branding and weaning percentages been trending? Where possible, look at these numbers separately for maidens, rebreeds and breeders. This will give you a nice breakdown of your reproductive indicators.

I'm probably going to upset some readers, however, biggest isn't best in a breeder operation. An unbalanced focus on size has had two major costs to the industry, particularly throughout northern Australia.

Firstly, as mature weight of breeders has increased, so has age of puberty. This has decreased conception and re-conception rates in heifers. There are a lot of heifers not turning grass into weaners for a few years.

Secondly, bigger cows eat more food. They require more nutrients to maintain their bigger bodies. Production comes from nutrient intake above maintenance. Bigger cows need a lot more food to put the same amount of nutrient into production (where you make money). Because they eat more, you then need more hectares to run the same number of cows. You can run 17 per cent more 500kg cows than you could 600kg cows. That is pretty significant when the research I've found indicates that the 600kg cow does not produce a bigger weaner ... mainly because the necessary nutrition isn't available most years.

What is happening to your mature cow body weight over time?

You don't optimise profit by having the biggest cows; you make money from converting available grass into the most kgs weaned.

My advice is match breeder size to land type. Better country can support a bigger cow. In lighter country, a moderate-sized cow will make you more money. Select for fertility first, growth second. Growth only matters when they are on the ground.