Farmers' net cash income this year probably will be greater than predicted a month ago despite the drought, and it may exceed last year's record, the Agriculture Department said Friday.

"Although some crop farmers have suffered severe losses, others with irrigation or normal rainfall have benefited from the higher prices," the department's Economic Research Service said."Higher feed costs and poor range and pasture conditions are hurting livestock incomes," it said.

The higher prices and reduced harvests this year will cut deeply into U.S. farm exports in 1988-89, the report showed.

No dollar estimates were included, but the report said the higher prices and "generally adequate supplies abroad" will likely reduce the 1988-89 volume of wheat exports by 12 percent, corn by 4 percent and soybeans by 29 percent.

Farmers suffering severe losses will get some relief from the recently enacted $3.9 billion disaster assistance legislation, the report said.

Nationally, net cash income - the difference between gross cash income and cash expenses - was forecast to be in a range of $55 billion to $60 billion, compared with the rec-ord of $57.1 billion in 1987.

Catle disease?

An estimated 14,000 catle in North Dalota are being tested for bovine tuberculosis, and authorities are tracing cattle sold in Iowa, Minnesota, South Dakota and Texas that might have been exposed to the infectious desease, the Agriculture Department said Friday, James Glosser, administrator of the deparment's Animal and Plant Health Inspection Service, said federal and state officials traced the suspected cattle to a herd in Wyndmere, N.D.