AN Agriculture Department study comparing the economics of autumn and winter calving at Alcoa Farmlands shows that winter calving, while increasing operating profit, was also not without challenges.
The aim of the trial, now in its third year, was to test the hypothesis that economic and environmental sustainability could be improved by calving in winter when feed supply matched feed demand.
Another aim was to validate different growth paths to meet market requirements and increase the proportion of cattle meeting specifications.
All cattle in the trial, being conducted at Alcoa's Wagerup and Pinjarra properties, are sold in January.
The Department recently found that the lower cost of production gained through less supplementary feeding and higher stocking rates in winter outweighed the higher returns from autumn calves.
Winter calving progeny put through fast, slow and compensatory growth paths also confirmed their potential at the processing end of the food chain.
Beef research officer Donna Read, in an outline of the winter calving project at the beef information day, said there was also no detrimental effect on cow or calf performance from winter calving.
She said calving time was an important consideration in trying to increase a year-round supply of cattle.
Alcoa Farmlands manager Tony Hiscock said his region was without rainfall for seven months of the year, and the cost of supplementary feeding was often lost.
He knew some farmers who did not think about how much supplementary feed they needed and simply followed the previous year's consumption.
"I am not saying we were particularly different in that," he said.
"But when you make less money you start to look into your business and find out what these things are," he said.
"There is potential for higher stocking rates in winter calving, there is no doubt about that."
Mr Hiscock said rotational grazing had so far increased autumn calving stocking rates by 0.2 breeding units a hectare over set stocking rates, while winter stocking rates exceeded autumn stocking rates by 0.2 breeding units again.
He said winter calving meant there was less need for supplementary feeding, for a cow without a calf, but extra calving management was needed to ensure cows did not become over-conditioned, which could lead to calving problems.
He said winter calving cows should ideally be of condition score 3, especially for first and second calvers.
"The weight or condition of your animals is absolutely vital," he said.
Milk scours was yet to be quantified and calving conditions in winter was more difficult than in autumn in his region.
Mr Hiscock said while winter calves weaned lighter, the compensatory growth path results showed winter calves could catch up on autumn calves.
"I am amazed at the compensatory growth path results," he said.
He said future work in the trial, which had another two years to run, would include finding out the cost of growth of lighter weaners to market weight.