Benchmark set for protein production

Beefed up numbers: Net protein contribution scores typical Australian beef production systems make to human nutrition. Source: CSIRO

New research by CSIRO has for the first time quantified the contribution Australian beef makes to the protein supply for human nutrition, paving the way to better understand efficiencies across production of other proteins.

The team measured the quality and quantity of protein created by cattle compared to the protein they ate, looking at both grain-fed cattle and grass-fed cattle that may eat small amounts of grain.

The research found typical Australian grain-fed beef production systems contribute almost twice the human-edible protein they consume, while grass-fed systems produce almost 1600 times.

It means the beef sector now has benchmark figures for the protein it contributes to the food supply, which will help track improvements and compare efficiency to other protein production systems when they are assessed using the method.

Red meat is often criticised as having a large footprint, taking up land that could be used to grow crops for human food, or eating grain that humans could be eating instead, otherwise known as the ‘feed versus food debate’.

However, CSIRO livestock systems scientist Dean Thomas said Australian beef production was efficient at converting both low quality protein in grains that humans can eat, as well as protein in grass that humans can’t eat, into high quality protein for human nutrition.

“Cattle are efficient up-cyclers of grass and other feedstuffs not just in terms of the quality of protein they create,” Dr Thomas said.

“They contribute a greater amount of protein to our food system than is used in their production as well.”

The study, published in the journal Animal, is the first time the net protein contribution concept has been applied in Australia.

It rated Australian grain-fed beef a score of 1.96 and grass-fed with a very small amount of grain a score of 1597, where a number greater than one means it has a positive contribution to meeting human nutritional requirements.

To test the assumption that grain-fed beef competes with humans for protein, the team modelled real world data in typical Australian beef production systems including methane emissions, historical climate records and commercial feedlot diets.

Dr Thomas said the rations now fed to cattle in Australian feedlots could be quite low in human-edible protein sources.

“The feedlot sector increasingly uses locally available by-products such as spent grain from bio-alcohol, feed-grade grain and cottonseed, while still meeting nutritional requirements for cattle,” he said.