An estimated 487,200 tonnes of genetically modified material, by weight, was used in animal feed in Australia in 2006-07, according to an Australian report.
This represented about 5% of all feed grains by weight used in that year, with proportions varying across the livestock industries, depending on the feed mix used.
It is estimated the chicken-meat industry on average used the largest volume of GM feed grain in 2006-07, followed by the egg and dairy industries.
The report, entitled "GM stockfeed in Australia: Economic issues for producers and consumers", was produced by the Australian Bureau of Agricultural and Resource Economics (ABARE).
The report commented on the situation in other countries, including New Zealand.
"New Zealand does not produce GM crops, making imports the only possible inclusion of GM ingredients in stockfeed. Imports of soybean and canola meal may be included in feed rations.
In 2006, around 96% of New Zealand's soybeans and meal imports came from GM soybean-producing countries.
"Accounting for the proportion of GM soybean plantings in these countries, it is estimated that around 68% of soybean meal imports were GM.
"All imports of canola meal were from Australia, making all canola imports in 2007 non-GM.
"As New Zealand does not produce soybeans, the reliance on imports means there is a high likelihood GM varieties are imported and included in stockfeed."
The report said that there is no reliable data on total stockfeed usage across the New Zealand livestock industry.
The New Zealand feed manufacturer's association (NZFMA) - a body representing around 85% of the total feed industry - indicates that more than 800,000 tonnes of stockfeed was produced in New Zealand in 2007.
The report pointed out that there are no import regulations specifically for products from animals fed with GM feed in any of Australia's major livestock product export markets, nor is there evidence of mandatory labelling requirements either in Australia or its major export markets.
Limited available evidence suggests consumer awareness of the current use of GM ingredients in stockfeed appears to be low both in Australia and its major export markets for meat, egg and dairy products.
"The few studies conducted on consumer acceptance in Australia and the United States indicate some consumer aversion to consuming products from animals fed GM feed.
"However, there is no evidence to suggest this is lowering demand for products from animals fed with GM stockfeed. Of Australia's major export markets, only some sections of the dairy and pig meat markets in Japan have required that only non-GM stockfeed be used in livestock product production.
"There are no reports of animal products being rejected by importers because of the use of GM feed.
"Given current GM regulations, and degrees of consumer acceptance and awareness in Australia and its major livestock product export markets, it seems unlikely Australian livestock producers who choose to use GM feed will be disadvantaged.
"Market developments require ongoing monitoring from producers and suppliers as demand for products from animals fed GM feed may change as consumer awareness and acceptance evolves, and as more GM crops and pastures are introduced to livestock feeding systems."