ABS said the reduction in quality was a result of the poor season and difficult harvest conditions.
Stocks of milling grade wheat grain were 5.1 million tonnes at the end of August 2011, a decrease of 996,000 tonnes from the previous month. Stocks of feed grade wheat grain were at 4.7 million tonnes at the end of August, a decrease of 657,000 tonnes, or 12% from the end of July 2011.
At the end of August 2011 Australia's bulk storage of wheat grain was estimated at 9.8 million tonnes, which was a decrease of 14% compared to July 2011. Stocks were up 3.1 million tonnes or 46% compared to July 2010.
All states reported decreases in stocks of wheat grain compared to July 2011, following the expected pattern of post-harvest decline.
New South Wales and Australian Capital Territory stored the largest amount of grain at 3.8 million tonnes despite a fall of 15% from July 2011.