Water Resources and Livestock: An increasing constraint
Water is essential for life. More than half of all potable water is from rivers and lakes and more than one-sixth of the Earth’s population rely on glaciers and seasonal snowfall for their water supply. However, the increase in surface temperatures is causing profound alterations in the hydrological cycle, particularly in regions where water supply is currently dominated by melting snow or ice.
Vanishing glaciers will negatively affect water supply in the next few decades in many parts of the world, for example in the Hindu Kush-Himalaya region covering parts of China, India, Afghanistan, Pakistan, and Myanmar, and in the South American Andes where Peru alone has lost 25% of its glacier-covered regions in the last 30 years. On the other hand, rivers currently fed by rainfall and snowmelt might instead pass to a rainfall-dominated regime resulting in an increase of water discharge in winter and a decrease in summer. This will have serious socioeconomic implications due to a reduction in water supply for industry, agriculture, and domestic use, as well as reduction of hydropower generation in summer.
Global warming is causing serious deleterious effects to the environment. The maintenance of stable water temperature in oceans, lakes, and rivers is extremely important for aquatic animals as small temperature variations can affect feed availability, egg hatchability, and survival; furthermore, elevated ambient temperatures prompt higher water consumption in humans and all terrestrial animals.
Changes in the hydrological cycle may cause more water to be deposited in the oceans at some periods of the year and an increased scarcity of water in others, while accelerated melting of glaciers and increasing use of fossil water will lead to severe shortages of water that will affect millions of people in the mid-term future unless governments jointly agree on and implement appropriate measures to reduce greenhouse gas emissions into the atmosphere.
The world is facing alarming food insecurity due to the adverse effects of climatic changes on crop and livestock productivity, increased demands from emerging markets in Asia and Latin America, use of grains in the production of biofuels, and reduction of arable land due to increasing urbanization. The Food and Agriculture Organization of the United Nations (FAO) has indicated that one billion of the world’s 6.5 billion people face hunger and are “food insecure”.
Humans, animals, and plants compete for water and it is by far the most important limiting factor in livestock production however, fresh water resources are not evenly distributed in the world and these resources are being increasingly depleted. Although much research is being done, it needs to be focussed on overcoming the significant obstacles to sustainable food production in order to create the means to double the worlds’ food production using less land, less water, fewer nutrients, and less technology to satisfy the expected demand.
There is increasing competition for irrigation water for both human consumption and the production of cereal crops that is likely to force a reduction in usage of irrigated pastures for livestock and a movement of livestock production into rainfall based grazing systems probably with the creation of feedlot finishing systems close to large cities.
- - Global warming is causing severe alterations in the hydrological cycle.
- - There is an uneven distribution of water resources around the world.
- - Humans, animals, and plants compete for water resources.
- - Livestock produced within rainfall grazing systems or fed with crop residues and agro-industrial by-products provide high quality animal protein for the human being without significantly affecting demand on water resources.
The major area for improvement in water use efficiency and productivity for livestock is through improvements in livestock and feed base management to maximize production efficiency and ensure better livelihood to the rural population.
The International Atomic Energy Agency (IAEA) through the Animal Production and Health Section has continued to support research and developmental work in developing countries over the last 30 years for improving quality and availability of local feeds and in the formulation of improved quality rations, and to genetically improve the local species and breeds for higher production while conserving their characteristics for adaptation to harsh environments and prevailing diseases. Large numbers of grasses and leguminous pasture species has been evaluated and proved to be resistant to high humidity or prolonged periods of dryness, to acid or saline soils, and to high altitude environments, and are currently being used for feeding livestock ruminants by farmers in developing countries.