Feed resources vis-à-vis livestock and fish productivity in a changing climate

Globally, livestock contributes 40% to agricultural gross domestic product (GDP), employs more than 1 billion people and creates livelihoods for more than 1 billion poor. From a nutritional standpoint, livestock contributes about 30% of the protein in human diets globally and more than 50% in developed countries. Aqua culture accounts for nearly 50% of global seafood production and employs more than 100 million people. As outlined in the livestock revolution scenario, consumption of animal-sourced food (ASF) will increase substantially, particularly in the so-called developing countries in response to urbanization and rising incomes, offering opportunities and income for smallholder producers and even the landless, thereby providing pathways out of poverty. It is important to recognize that the increasing demand for ASF pertains to ruminants (meat and milk), monogastrics (broilers, eggs and pork) and aquatic animals such as fish. To put it differently, much more animal feed will be needed for all domestic livestock and farmed aquatic animals in the future. Competition for feed among livestock and fish species will increase, in addition to competition with human food production and biomass needs for biofuels and soil health, unless we see significant levels of intensification of ASF production, and in ways that are environmentally sustainable. Animal source food production globally already faces increasing pressure because of negative environmental implications, particularly because of greenhouse gas emissions. As livestock and aquaculture are important sources of livelihood, it is necessary to find suitable solutions to convert these industries into economically viable enterprises, while reducing the ill effects of global warming. In relation to climate change, ASFs will have to play a dual role: one of mitigation and the other of adaptation. The most evident and important effects of climate change on livestock production will be mediated through changes in feed resources. The main pathways in which climate change can affect the availability of feed resources for livestock - land-use and -systems changes, changes in the primary productivity of crops, forages and rangelands, changes in species composition and changes in the quality of plant material - will be discussed in the chapter. The chapter will propose an environmentally friendly development of livestock production systems, where increased production will be met by increased efficiency of production and not through increased animal numbers. For aquaculture, the focus will be on better sourcing of feedstuffs and on-farm feed management. Feeding strategies that increase the efficiency of production by producing more from fewer livestock animals and less feed will result in reduced greenhouse gas emissions. This will be demonstrated by analysing livestock populations in India and their respective level of productivity. Thus, in India in 2005/06, the daily milk yield of cross-bred, local cows and buffalo averaged 3.61 l, resulting in a ratio of feed metabolizable energy (ME) for maintenance and production of 2.2 to 1. By increasing daily milk production in a herd model (of a mixed cross-bred, local cow, buffalo population) from 3.61 to 15 l day-1, energy expended for maintenance becomes 1:1.91. As a result, the same amount of milk can be produced by fewer livestock, leading to a reduction in emissions of methane of more than 1 million tonne (Mt) year-1.