The campaign to curb bird flu on the nation’s farms has been slowed by the chaotic transition to a new administration that is determined to cut costs, reduce the federal work force and limit communications, according to interviews with more than a dozen scientists and federal officials.

On poultry farms, more than 168 million birds have been killed in an effort to curtail outbreaks. Since the virus first appeared on American dairy cattle about a year ago, it has spread to 17 states and infected more than 1,000 herds.

In its first months, the Trump administration has fired teams of scientists crucial to detecting the spread of the virus, canceled important meetings, and limited access to data even for federal scientists.

The Department of Health and Human Services has not held a public news briefing on bird flu since January, and did not respond to requests for comment.

Robert F. Kennedy Jr., the health secretary, has suggested allowing the virus to spread uncontrolled through poultry flocks to identify birds that might be immune, an idea that scientists called reckless and dangerous. His comments prompted Democratic lawmakers to open an investigation into the federal response.

The Trump administration has also eliminated funding for programs at the Food and Agriculture Organization, an agency at the United Nations, that monitor and contain bird flu in 49 countries.