INCREASING cow size can be a double-edged sword. The trick is to understand where the sweet spot lies between the size that suits your feed availability and your target markets.
The prices of the day can also shift the best size up or down, depending on the ratio of return, versus cost per unit of input required to get them to market.
Right now, the strong prices are in favour of larger females, says Dr John Webb-Ware. The consultant for the University of Melbourne faculty of agricultural science run McKinnon Project, at Werribee in Victoria, conducted the modelling for this project in the program GrassGro, a tool developed by CSIRO Plant Industry to assist decision making in sheep and beef enterprises.
He used a typical self-replacing August-calving Angus herd modelled across 30 years, using a range of commodity prices.
“With the higher commodity prices, you can certainly chase the bigger cow size a bit harder at a slightly higher stocking rate,” he said.
However, the stocking rate was still key, because the harder it was pushed, especially as cow size increased, the more risk the producer carried.
Keeping this in mind, Dr Webb-Ware said there were two sides to the cow size equation.
“Firstly, larger cows will generally produce larger progeny so you would expect progeny would generally meet market specifications a bit earlier and also reach heavier weights, so potentially be more valuable,” he said.
Along with reaching markets earlier, he said providing those larger calves had the ability to finish at any age, they would also be able to meet a larger range of markets.
Meanwhile, the larger cows (be they dry, cast for age or just surplus to requirements) would be more valuable when sold.
This was important because cows contributed to as much as 40 per cent of the average beef operation’s income, he said, referring to Meat and Livestock Australia figures.
“On the other side of the argument, you’ve got the issue that these animals consume more feed,” he said.
“So unless they’re more efficient at converting feed, which they’re not necessarily – as you increase mature cow size, you’re increasing the feed demands of the animals.”
This was okay if the farm consistently produced surplus feed.
“There is no doubt the bigger cows can produce more beef per hectare, but that extra beef is (often) negated by the extra costs of supplementary feeding,” he said.
On properties which were already well stocked, an increase in cow size generally meant an increase in risk.
Therefore, Dr Webb-Ware’s tip for those who were chasing growth (especially 600-day growth), was to keep a cap on mature cow size.
“If you are increasing cow size, it’s particularly important not to chase animals which are too lean,” he added, due the negative effects this could have on fertility.
Cow size was the focus of Dr Webb-Ware’s seminar “Which is more profitable? Big or small cows” at the recent Border Beef Conference in Albury.
Building the most efficient herd
BIG or small cows? This was the focus of a recent talk at the Border Beef Conference at Albury for MacKinnon Project consultant, Dr John Webb-Ware.
He concluded small mature cows best suited a terminal system where the cows were crossed with a large-framed, high growth terminal sire, especially under current market conditions where higher prices helped balance the cost of larger cows in a self-replacing herd.
By using smaller cows in this way, more could be run, and if joined to a larger bull, such as typical for a European breed, they could still breed large calves.
He said the larger-framed terminal sire got around the challenges of meeting a range of markets that were otherwise typical when using smaller cows in a self-replacing herd.