Livestock production in a world with less grass

TitleLivestock production in a world with less grass
Publication TypeConference Proceedings
Year of Publication2012
AuthorsHavstad K, Estell RE, Anderson D.M., Schrader ST, James D.K, Cibils AF
Conference Name17th Wildland Shrub Symposium
Volumep. 19-20
Date Published05/2012
PublisherWildland Shrub Symposium
Conference LocationLas Cruces, NM
ARIS Log Number286350

The world’s ice-free land surface is ~147.3x106 km2. Rangelands comprise 54% of this area, ~80x106 km2. Only 16%, 12.8x106 km2, of this rangeland type is classified as grassland. The predominant vegetation type is simply categorized as “woody”, and currently covers 37.9x106 km2. Though grass dominated rangelands occur on all continents, it is wholly inaccurate to think of rangelands as characteristically “grasslands”. In fact, the grasslands that exist are commonly in decline for a variety of reasons, though two dominant factors are the continued conversion of native landscapes to cropland and the encroachment of existing native landscapes by woody plants. Given that global cereal production is anticipated to increase by approximately 1 billion tons over the next 2 decades, the conversion of rangeland to cropland will likely continue unabated. Concurrently, continued land degradation, reduction or elimination of prescribed burning, and increased atmospheric CO2, as well as continuation of other drivers, will further promote expansion of woody plants. In parallel with these trends is the continued, stunningly rapid increase in global numbers of livestock over the past 5 decades. In 1960, global numbers of cattle, sheep and goats were ~2.4 B head. Today, global numbers of livestock are in excess of 3.0 B head. Given the escalating demands for red meat by the world’s 7 B human inhabitants, especially driven by growing economies in Asia, this demand will likely not lessen. The Food and Agriculture Organization has estimated that by 2030 there will be 4.2 B head of livestock around the world. Though reliance on intensive livestock production systems has grown in recent decades, about 1/3rd of livestock worldwide are raised within extensive, grazing-based production systems. About 70% of these animals are within rangeland systems in developing countries, a situation that contributes to the fact that 1 in 10 people around the world are engaged in animal husbandry. It should be evident that we are faced with the need to produce livestock in a world with less grass not only today, but for the decades ahead in the 21st century. This will require employing a number of management strategies that will utilize the predominately woody components of the worldwide forage base within our rangeland environments.