Ask Dairy - Environmental Impact

"There is a lot of confusion surrounding the best way to measure environmental impact of the dairy industry. Which way do think best reflects the real impact?"

The dairy industry exists to produce milk, cheese, butter and other dairy products in addition to by-and co-products such as beef and leather - it does not exist to produce cows, heifers or other animals. The environmental impact is best and most accurately served and compared between systems by expressing on a “per unit of dairy” basis, e.g. per litre, kg or tonne of product. Although it’s tempting to express per head of cattle, this leads to considerable confusion – nobody would suggest that a 400 kg Jersey cow would eat as much or emit as much greenhouse gas as a 680 kg Holstein cow, and nor would they produce the same amount of milk, yet they would be counted as the same animal on a “per head” accounting system. The question then becomes whether the “per unit” metric is sufficient, or whether account should be taken of the nutrient content of differing products so that, for example, fluid milk could be compared to cheese or to soy-based beverages. It seems likely that an environmental impact per nutrient supply unit may be used in future.

Expert Answer by: Judith Capper