Livestock nutrition – a perspective on future needs in a resource-challenged planet

Global agriculture will be challenged by future population growth in the developing nations in Africa and Asia, concurrent with regional changes in climate that will adversely affect local crop and fodder production. The uncoupling of animal production from land area by global trade in high energy grains and protein meals, which has underpinned industrialised livestock production in the developed world, is forecast to continue in some population growth hotspots of the developing world. However, the projected rise in fossil fuel costs and the greenhouse gas emissions associated with their use will increasingly favour use of non-cereal energy sources, and the extent of feeding cereal grains to livestock in the developing world into the middle of this century is uncertain. Meeting the developing world’s growing demand for meat, milk and eggs in the face of the 3-fold challenge of population growth, climate change and fossil energy decline, demands a fresh vision, and the development of fresh technologies for animal nutrition in coming decades. How can high efficiency production be achieved from feeds of low metabolisability? This question is as critical for aquaculture as it is for land-based production. Enhancing ruminant capacity to generate animal product from crop by-products is fundamental in this achievement, but livestock access to crop residues will be in competition with the emerging second-generation (cellulosic) biofuels industry. Industrial technologies that treat crop residues to improve their nutritive value at source, not just as end-user treatments, will be required. There is scope to boost animal production and also reduce enteric greenhouse gas emissions (e.g. nitrate supplements) and the expanded capability in rumen microbiology may deliver targeted tools to mitigate emissions and increase energy yield from cellulosic feedstuffs. The greatest challenge of tomorrow’s nutritionist, however, is to provide local feed energy resources and enhanced nutrient utilisation, allowing a high yield of animal product without reliance on imported cereal grains and oilseed meals.