Making useful new products from waste

Recycling and upcycling (reusing materials or waste to create higher value products) have become common practice in some industries. As technology improves, it becomes more common for manufacturers in other industries to turn their waste into useful products. Industrial amounts of farm waste are available across Australia and can contribute to farm income if converted into saleable products. Australian scientists are working to produce improved quality, lower-cost feed for farm animals such as cattle, pigs, and chickens by using a molasses-like syrup from the left over material on sugar cane farms. Using chemical processes, it is possible to upcycle large amounts of sugar cane leaves and the dry residue left after the extraction of juice from sugar cane stalk, called bagasse, into quality feed ingredients for farm animals. Australian agriculture is set to benefit from the development of new technologies to enhance the nutritional value of low value crop residues. This will increase the availability and reduce the cost of feed ingredients for animal producers.

The demand for Australian animal products (such as meat, cheese, and milk powder) in Asian countries continues to increase as regional population dynamics change and Asia’s middle class grows. Our agricultural sector is responding by increasing animal production to meet this demand. This means we need to produce more animal feed and the sector is actively looking for new feed ingredients that cost less, are more widely available, and have comparable or enhanced nutritional quality relative to existing feed ingredients.

Chemistry for future global impact

Animal feed containing lower cost but more widely available and nutritious ingredients like dietary fibre, sugar syrups, and protein will contribute to ‘future proofing’ the livestock industry in times of drought or flood. The lower cost of these feed ingredients will help ensure that grazing, pig, and chicken production businesses continue to thrive.

A team of scientists at Queensland University of Technology’s Centre for Agriculture and Bioeconomy (CAB) is developing enhanced chemical processes to produce valuable animal feeds from agricultural by-products including sugar cane bagasse and trash.

The key by-product from sugar mills, bagasse, is already used to produce heat, steam, and electricity to run the sugar mills. Sugar cane trash, on the other hand, remains unutilised on the paddock. In Australia, graziers do not fed these by-products to animals directly because they are not very nutritious. The structure and chemistry of the crop residues needs to change to turn sugar cane bagasse and trash into something that can help an animal grow.

Bagasse, a by-product of sugar production

Microbial production of high-quality feed protein using sugar cane by-products has significant implications for sugar cane producing countries, including Australia. The development of chemical technology to improve fibre digestibility will also benefit industry via production of a potential sugar syrup substitute for molasses.

To produce animal feed, biorefineries will need large quantities of crop residues such as sugar cane bagasse and trash. Sugar cane farmers and millers will benefit by being the sources of these raw ingredients. In turn, this will increase employment opportunities as well as stimulate regional economic development by providing a new income stream for crop producers and processors.

This project is supported by Sugar Research Australia through funding from the Australian Government Department of Agriculture and Water Resources as part of its Rural R&D for Profit program.