“Using 1944 as the base year of comparison, and also the year of the largest number of dairy cows in the United States, the number of dairy cows has dropped from 25.6 million to 9.2 million cows, while milk production has increased from 117 billion pounds to 186 billion pounds,” U of I’s Mike Hutjens said, as reported at CattleNetwork.com. “Using pounds of carbon dioxide per gallon of milk as the carbon footprint value, the dairy industry’s footprint has dropped from 31 pounds in 1944 to 12 pounds per gallon in 2007.”
Dairy cattle’s environmental impact continues in the news as global warming concerns are raised due to methane production and carbon dioxide relationships involved in the industry, Hutjens said. “Dairy cows produce methane when digesting feed in the rumen. Methane has 25 times the impact of carbon dioxide,” he said. “While a wide range of claims have been made, 6 percent of the total carbon footprint is from agriculture with dairy responsible for 11 percent of the total 6 percent, or 0.7 percent of the total.”