PU measures carbon footprint of dairy

WEST LAFAYETTE, Ind. - A Purdue University study is trying to determine the carbon footprint caused by producing a gallon of milk.

Calculating the carbon footprint made by producing a gallon of milk involves measuring everything from the fuel used by trucks and tractors to the electricity used by machines. The cows themselves also contribute. The Purdue study involves measuring and analyzing carbon dioxide, methane, and nitrous oxide released from cows at dairy farms.

Agriculture and Biological Engineering professor Albert Heber said the study could not only help the dairy industry lower green house gas emissions, but also find more efficient ways to recycle gases produced.

He said this type of study is difficult because of the environment it's conducted in.

"We have to come out to the farm and they're not set up for emission measurements and so that's why we have to bring a trailer, have some lab space, and try to assess the airflow. One of the biggest problems is to measure the barn airflow in a naturally ventilated building like this. That is not trivial," said Heber.

Heber says dairy farms account for less than 2 percent of total U.S. greenhouse gases.