Sustainable Livestock Management

Fig.1 Cows wearing backpacks to measure their methane output, at the Ellinbank Dairy Research Centre in Victoria, Australia (Source: ScienceNews)

The name Allen Savory kept coming up during my research into sustainable livestock management, who holds some intriguing claims such as ''livestock is the only hope for a dying planet''; ''only livestock can reverse desertification''. In his TED Talk, ''How to green the world's deserts and reverse climate change'', he challenged the conventional wisdom of regarding livestock as the reason of land degradation from grassland into deserts. 

Savory's hypothesis is based on the holistic management and planned grazing of livestock, which mimics the role of wild herds in nature, which he argues would increase the carbon sequestration in grassland, and counteract the methane production of cattle and even reverse climate change. Savory claimed that his experiments with livestock in Zimbabwe, Mexico, Argentina have successfully reversed degraded dry lands by increasing the stocking density, which is the number of animal grazing at a specific area of land, by as high as 400%. 

Although I am not fully convinced with his statements, I do think his claims are somewhat advisable. It is reasonable to research on a possible more sustainable management of livestock, especially considering that it is a major GHG emission source while a rise in the demand of animal protein is inevitable with the growing world population. Research has shown that the mitigation potential for GHG emission is huge. The new FAO report concluded that the existing livestock production system could cut emission by around 30%. 

Efficiency is key

According to the FAO, reducing GHG emission and improving efficiency measures, especially concerning the use of natural resources, are directly linked. This is based on sustainable intensification, i.e. producing more livestock protein with fewer input of resources, which reduces both the emission and the cost of farmers. Therefore, possible interventions to reduce emissions are largely based on measures to improve production efficiency. 

Enhancing efficiency measures include using better feeds and feeding techniques for ruminants. This can reduce GHGs generated during digestion as well as the released by decomposing manure. First and foremost, we need to feed animal with less human food. 
Livestock consumes about 1/3 or more of the world's cereal grain production, with 40% fed to ruminants, mainly cattle. It is said that cows produce more methane when they eat corn or soy-based feed or over-grown grass as they are harder to digest. A study from the National Trust found that grass-based beef production can reduce the agricultural carbon footprint, considering grassland carbon sequestration potentials. Although some papers hold the opinion of feeding livestock energy-dense feed such as cereal grain to improve production. 

Interventions aiming to improve breeding and animal health that would also help to reduce GHG emission. This can be achieved by adopting measure to improve the genetics of cattle. It would lead to a reduction in herd size, but an increase in production rate which increases the feed availability and productivity of individual animals as well as the total herd. Thus lowering the GHG emissions per unit product. 

Emissions can be reduced by manure management practices that ensure the recovery and recycling of nutrients in manure. For example, by storing manure appropriately to minimise the loss of nitrogen by volatilization and run-off.