World demand of animal products (milk, meat, eggs) is growing rapidly, especially in developing Countries, as population and income increase.
Livestock productions, however, imply some environmental issues: for example, they contribute to the production of greenhouse gases, release nitrogen and antibiotic residues into soil, water and air. Moreover, they use soil, a non-renewable and limited resource, for the production of animal feeds. Some animal productions have a higher impact than others; for example, the production of beef has a high environmental cost, whereas other kinds of meat (e.g. pork, chicken) have lower costs. Intensive farming systems, that concentrate many animals in a small area and make extensive use of production factors (tractors and machinery, fertilizers, herbicides, feeds, etc.), are generally accused of having a greater environmental impact than the extensive farms that use meadows and pastures and few production factors. This is true at local level when the evaluation concerns the effects on the environment (soil, water, etc.) where the farms are located.
Conversely, intensive farms use the production factors in a much more efficient way than the extensive ones, thus reducing the production of greenhouse gases, nitrogen excretions and soil use per kg food (milk, meat, eggs) with an advantage from a global point of view.
To protect the environment it is not necessary to definitely ban animal products from our tables but it is advisable that in western Countries the consumption of animal products are reduced and partially moved towards animal productions with a lower environmental impact.
From the point of view of production it is necessary to continue the efforts to mitigate the environmental impact of livestock farms, especially the intensive ones, through the adoption of production techniques more environmentally friendly.