Kenneth M. Birkhead, 64, a former Agriculture Department official, Senate aide and Democratic Party campaign executive, died of cancer Saturday in Durham, N.C., where he moved after retiring in 1978.

In his last position he had been special assistant to former senator Thomas J. McIntyre (D-N.H.), whose staff he had joined in 1969.

From 1961 to 1966, Mr. Birkhead was special assistant to secretary of Agriculture Orville L. Freeman. He then spent two years as administrator of the Agriculture Department's Rural Community Development Service. He received the department's Distinguished Service Award.

Mr. Birkhead was born in St. Louis, Mo. He graduated from Missouri Valley College and earned a master's degree from the University of Missouri. He served with the Army Air Forces Air Transport Command in World War II.

At one time, he was an assistant to his father, the late Rev. L. M. Birkhead, founder and director of Friends of Democracy.

Kenneth Birkhead came to Washington in 1948 to participate in President Truman's campaign for re-election. He was assistant to the chairman of the Democratic National Committee that year and again during 1950-52. He was finance director for the committee during 1957-59.

He was staff director for the Democratic Senate Campaign Committee in 1952-53 and assistant to the Senate majority whip during 1953-55.

In 1964, Mr. Birkhead was national director of Rural Americans for Johnson-Humphrey. Four years later, he was national executive director of the Citizens for Humphrey-Muskie campaign committee.

He had served as national director of the American Veterans Committee.

He is survived by his wife, Barbara, of the home in Durham; two sons, Scott, of Falls Church, and David, of Durham; his mother, Agnes Birkhead, of Falls Church, and two grandchildren. CAPTION: Picture, KENNETH M. BIRKHEAD