Pigs and Environment
In the context of the intensification of pig production and consequent higher animal densities, the environmental effects have to be considered. Global issues such as greenhouse gas emissions from livestock production are becoming internationally recognized.
The main direct environmental impact of pig production is related to the manure produced. Appropriate storage can reduce the amount of greenhouse gases released, and the production of combustibles through bio-digestion can help to make optimum use of the natural resources involved in the production cycle.
The level of manure utilization defines the amount of nutrients released into the environment. Such nutrients can contribute significantly to increased soil fertility when used appropriately, but an overload of nutrients and other substances can lead to soil and water degradation. High-density pig production can release excessive amounts of nitrogen and phosphorus into the environment, and the high doses of copper and zinc fed to pigs to promote growth eventually accumulate in the soil.
The Life Cycle Assessment (LCA) approach to measuring greenhouse gas emissions related to pork production indicates that it tends to have lower emissions than ruminant production systems.
More attention needs to be given to the positive environmental impacts of sustainable pig farming, especially when pig production is part of agro-silvo-pastoral systems or organic farming systems where outdoor production is integrated with crop rotation.