Agriculture: Steps to sustainable livestock

The need for efficient food production has never been greater. One in seven humans is undernourished. Urbanization and biofuel production are reducing land availability, and climate change, lack of water and soil degradation are decreasing harvests. Over the past decade, cereal yields per hectare have fallen in one-quarter of countries. Meanwhile, developing nations and the growing world population are demanding more animal protein….  Adopt smart supplements. The productivity of ruminant animals can often be boosted with supplements, some of which encourage microbes in the rumen to grow quickly and to provide better nutrition. In India, a water fern (Azolla caroliniana) cultivated in local ponds provides extra protein to cattle and goats fed on protein-deficient elephant grass (Pennisetum purpureum). Other plant extracts can alter the rumen microbial population to use nitrogen and energy more efficiently. This means producing more meat and milk with proportionally less by-product greenhouse gas and ammonia. An enzyme in red clover (Trifolium pratense), widely grown in temperate countries, increases ruminants' ability to utilize dietary protein. In field trials, dairy cows with more clover in their diets ate more feed and produced more milk. In Australia, sheep nibble on the deep-rooted perennial tar bush (Eremophila glabra) during dry autumns when most other pasture plants offer poor food value. Tar bush combats gastrointestinal nematodes and acidosis, and reduces emissions of methane, a greenhouse gas 25 times more potent than carbon dioxide….  There will be no one-size-fits-all solutions. Changing farming practices is difficult, but farm platforms can evaluate potential for increased profits and other benefits, act as examples to follow, and provide information for policy-makers. We hope to identify better practices to optimize the use of livestock in different regions, using local resources, breeds and feedstuffs — and produce tangible evidence to convince local farmers.

Eisler, M. C., M. R. F. Lee, J. F. Tarlton, G. B. Martin, J. Beddington, J. A. J. Dungait, H. Greathead, J. Liu, S. Mathew, H. Miller, T. Misselbrook, P. Murray, V. K. Vinod, R. Van Saun, & M. Winter (2014) Agriculture: Steps to sustainable livestock, Nature 507(7490):32-34.