May we use the "typical cow" as a source of green energy?

In the article about grain fed vs grass fed you stated, “The typical cow produces 200 to 400 quarts of methane a day.” Now, by no means am I trying to dispute said statement by the world’s smartest man; rather, can this be contained, collected, stored and/or harnessed for a positive use, with no further harm to the cows(aside from the electrical shock and spike or however it dies).
50-100gallons of methane a day X cows used for farming = a lot of methane?
p.s. - if my logic will benefit the world in a great way quickly, please bump it =)

Sincerely,
manonthemoon from tx

Closed as a duplicate of one posted to GQ and moved to CCC.

Colibri
General Questions Moderator