Paul B. Zumbro, 75, a retired Agriculture Department official and an authority in poultry science, died of a brain tumor Monday at Fairfax Nursing Center.

He had worked for the Agriculture Department for 46 years. From 1961 until retiring in 1972, he was assistant chief of the poultry research branch of the Agricultural Research Services' Animal Husbandry Research Division.

Mr. Zumbro came to Washington in 1935 as senior coordinator of the Agriculture Department's poultry improvement plan. In this position he helped to tighten disease and breeding controls in poultry hatcheries and wrote technical works on the project.

He was a member of the U.S. delegation to the World Poultry Congress held in Denmark in 1946, was a consultant to the congress in Mexico in 1958, and was elected a fellow of the Poultry Science Association in 1969.

His government awards included the Agriculture Department's Superior Service Award in 1948 and its Outstanding Performance Award in 1960.

Mr. Zumbro was a native of Washington County, Ohio, and a 1926 graduate of Ohio State University. He received a Distinguished Alumni Award from Ohio State's College of Agriculture in 1972.

Before coming to this area, he worked as an Agriculture extension specialist in Ohio for nine years. He had lived in Hyattsville for the past 34 years.

His wife, Katharine S., died in 1978.

Survivors include three sons, Air Force Lt. Col. Paul E., of Highland, Calif., Navy Cmdr. S. B. Zumbro of Springfield, and Val. E., of Burlington, N.C.; two sisters, Mildred Morin of Newark, Ohio, and Pauline Harris of Chesterhill, Ohio, and six grandchildren.