The contribution of breeding to reducing environmental impact of animal production

Animal production is responsible for 14.5% of total anthropogenic greenhouse gas (GHG) emissions. Approximately half of these emissions originate directly from animal production, whereas the other half comes from feed production. Animal breeding aims at improving animal production and efficient use of resources, which results in a reduction of environmental impacts. The objective of this study was to quantify the contribution of animal breeding to reducing the environmental impact of the four major livestock species in the Netherlands (with their animal product), namely broilers (meat), laying hens (eggs), pigs (meat) and dairy cattle (milk). This study comprised of a literature review and a quantitative assessment of the current environmental impact and the result of recent genetic improvements. For broiler meat, chicken eggs and pig meat the focus was laid on GHG emissions and nitrogen and phosphorus efficiency, whereas for dairy the focus was laid on enteric methane emissions, an important contributor to GHG emissions. Results show that breeding reduces environmental impacts of animal products by about 1% per year. This is achieved without specific selection on environmental traits, but as an indirect response through selection on increased (feed) efficiency.