Great progress has been made in reducing human starvation. This has been achieved through increased use of arable land and adoption of new technologies. Future increases in food production will depend on adoption of new technologies and must be more rapidly achieved to meet the increased demand for food. Technologies that are safe for people, reduce environmental impacts of production, increase profits, and improve animal well-being will be needed. The EU precedent in banning hormonal growth promotants (HGP) was a response to the illegal abuse of diethyl stilboestrol in the EU and provides a non-tariff trade barrier. The banning of some antibiotics in the EU reflects the unwise application of a ‘precautionary principle’ through which risks were not soundly assessed. However, the unilateral ban established by Coles on HGPs in Australia represented a more dangerous development in which marketing ploys were accorded a higher value than the care of animals, the environment or the profit made by producers. Decisions such as these have reduced the viability of animal production in the UK and pose a threat to sustainable agricultural production in Australia.
Marked increases in atmospheric CO2 concentrations are largely associated with the release of sequestered carbon in fossil fuels. While emissions of green-house gasses (GHG) from cattle have significant global warming potential (GWP), these are biogenic sources and substantially involve carbon in natural cycles, rather than fossil fuel. Cattle utilise human inedible feeds and by-products of human food production to produce nutrient dense foods of great value to humans.
There are marked differences in the chemistry of GHG, with methane having greater radiative forcing effect (34 times) greater than CO2, but a much shorter half-life than CO2 having effect for 12 years v tens of thousands of years. Estimates of the effects of ruminants on global warming have been focussed on the emissions produced, but have not considered the benefits in terms of maintenance of grassland and forest environments, nor considered implications for the food chain or social structures in some regions. These considerations are complex and require deep considerations of sustainability. Fortunately, there is much that can be done to reduce the impacts of cattle production on GHG intensity and overall production. There is potential for the profession to play a positive role in this area of responsibility.
There is potential for the veterinary profession to play a positive role in reducing the intensity and overall production of green-house gasses (GHG) from cattle.
Interventions to reduce GHG production include reductions in land clearing and burning of grasslands and increased carbon sequestration in soils and trees. Increased efficiencies of production through intensified feeding and enteric modification have markedly reduced intensity of GHG emissions for cattle. Improved reproductive performance reduces intensity of GHG emissions, especially in beef production. Feeds and technologies that reduce GHG production and intensity include improved pastures, grain feeding, dietary lipids, nitrates, ionophores, seaweed, 3-NOP, hormonal growth promotants in beef, and improved diets for peri-parturient dairy cattle.
There is a need to provide better environments for cattle. Cattle are susceptible to heat stress and ameliorating interventions include tree and shelter belts, shade, housing, cooling with fans and water and dietary manipulations.
Conclusion: Numerous interventions can reduce GHG emissions and intensity from cattle. There are opportunities to increase carbon capture and maintain biodiversity in Australia’s extensive rangelands, but these require quantification and application. We can reduce the intensity of CH4 emissions for cattle in Australia and simultaneously improve their well-being.