In an Australian first, the national science agency CSIRO has measured the 'net protein contribution' of beef to human nutrition. It means the quality and quantity of protein created by cattle can be measured in comparison to the protein they eat.
This research was undertaken as part of CSIRO’s Future Protein Mission, which aims to improve the productivity and sustainability of new and existing Australian protein industries through science, innovation and technology.
Future Protein Mission lead Professor Michelle Colgrave said that it was critical for Australia to obtain these benchmark figures for the beef supply chain.
“Research like this could help consumers assess their options in terms of what protein foods they choose in relation to sustainability,” Colgrave said.
The study looked at grain-fed and grass-fed cattle that may eat small amounts of grain. It found typical grain-fed beef production systems contributed close to twice the human-edible protein they consumer, while grass-fed systems produced almost 1600 times.
CSIRO said it meant the sector now had benchmark figures for how much protein it contributes to the food supply.
CSIRO livestock systems scientist Dr Dean Thomas said red meat is often criticised as having a very 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, Australian beef production is 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 upcyclers of grass and other feedstuffs not just in terms of the quality of protein they create. They contribute a greater amount of protein to our food system than is used in their production as well,” Thomas said.
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.
The net protein contribution concept rates beef where a number greater than one means it has a positive contribution to meeting human nutritional needs. Australian grain-fed beef scored 1.96 and grass-fed with a very small amount of grain scored 1597.
Thomas said the rations now fed to cattle in Australian feedlots can 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,” Thomas said.
The study was published in the journal Animal.
