Washington ? The government is easing rules intended to prevent the spread of mad cow disease among people, allowing part of a cow’s small intestine to be used as casing for some sausages.

Rules in effect after discovery of the first U.S. case of mad cow disease in 2003 required the removal of the small intestine when a cow was slaughtered.

The Agriculture Department and Food and Drug Administration cleared the way on Wednesday for a portion of the small intestine to be used as a casing for specialty sausage.

The rules still prohibit use of the lower end section of the small intestine, called the distal ileum. Studies have shown the distal ileum can contain the infectious protein that causes mad cow disease.

The Agriculture Department now knows more about effectively separating the distal ileum from the small intestine, said Daniel Engeljohn, an official of the department’s Food Safety and Inspection Service.

Prohibiting the distal ileum provides the same level of protection as prohibiting the entire small intestine, he said.

The department is aware of the financial hardship on businesses that make ethnic sausages, Engeljohn said.

The nation’s first case of mad cow disease, confirmed in December 2003, was in a Canadian-born cow in Washington state. The second case, a Texas-born cow, tested positive in June.

Mad cow disease is the common name for a brain-wasting disease called bovine spongiform encephalopathy, or BSE. In people, eating meat products contaminated with BSE has been linked to about 150 deaths from a rare but fatal degenerative disease called variant Creutzfeldt-Jakob disease.