Harvard students who enjoy hard-boiled or fried eggs in the dining hall will soon be munching with a cleaner conscience. Harvard University Dining Services (HUDS) announced yesterday that it will start serving cage-free shell eggs, which come from free-roaming hens, on May 7.

But students who prefer their eggs in omelette or scrambled form will have to wait, since the liquid eggs HUDS uses will continue to come from caged hens. The cage-free shell eggs will represent about a quarter of HUDS’ total egg use.

The move came a day after Law School Dean Elena Kagan announced that the school’s food company, Sodexho, is also “moving toward using cage-free eggs.”

HUDS’ decision comes on the heels of a campaign begun last November by Harvard students urging the University to stop purchasing eggs from caged hens. A core group of about 10 to 15 spearheaded the effort and circulated an anti-caged eggs petition signed by over 1,000 students, according to Annalise S. Hoopes, a student at the Graduate School of Education and a leader in the campaign.

HUDS Director for Marketing and Communications Crista Martin said that the switch had been in discussion for years, and was not a direct result of the petition.

“HUDS is making the switch after a careful review of vendors, cost implications, sourcing options, and a review of other college programs,” HUDS Executive Director Ted A. Mayer said in a statement. “I am very pleased that we are able to take this next step in our continuing effort to provide great local products that offer the quality and freshness that are so vital to us.”

HUDS called the humane aspect of going cage-free an “added benefit.”

The switch will cost Harvard $20,000 a year, according to Martin.

“We’ll have to spend some time this summer for ways to find efficiencies that make up for that,” Martin said. “The board rate is what it is.”

Martha Nussbaum, a visiting scholar at the Radcliffe Institute who has advocated a switch to cage-free eggs, called HUDS’ decision a start.

“Hens in factory farms are forced to live their entire lives in barren batterycages—unable to stand upright, walk, or spread their wings—each given only 67 square inches of space,” Nussbaum wrote in an e-mailed statement. “Many battery-caged hens are already crippled with broken wings and legs, if not already dead, at the time of slaughter.”

Nussbaum, who declined to be interviewed, added that HUDS should offer more humane food options, such as free-range beef.

“It would be quite interesting to offer options from humane farms, and see whether students would be willing to pay a little more,” she said. “The time has come to offer humane alternatives.

—Staff writer Margot E. Edelman can be reached at medelman@fas.harvard.edu.