MADISON — Half of a Manitowoc County elk herd exposed to chronic wasting disease was killed for testing Tuesday, May 6, agriculture officials announced.

About 90 elk from Eugene Sperber’s 180-head herd were put down beginning at about 8 a.m. The remainder of the herd will be destroyed when storage space is available for the carcasses, which must be refrigerated until test results are available.

One elk from the herd tested positive for CWD in March. It was one of 20 animals that Sperber, of Valders, bought from a Minnesota farm later found to be infected with the fatal disease. None of the rest of the Minnesota animals tested positive. One had died previously and was not tested.

Veterinarians and technicians from the Wisconsin Department of Agriculture, Trade and Consumer Protection and the U.S. Department of Agriculture put the animals down. Elk were heavily sedated and shot with the same type of gun used for commercial cattle slaughter.

Brain stem samples were removed from each elk and shipped to the National Veterinary Services Laboratory in Ames, Iowa, for testing. The carcasses will be stored until test results are back. Carcasses from CWD-positive animals, if any, will be incinerated at Midwest Cremation Service of Wisconsin, Poynette. Carcasses of negative animals will be landfilled. Test results are expected within three weeks.

Sperber will be required to burn or bury all feed, bedding, manure and wooden feed troughs used by the deer. He also must clean all organic material from metal, concrete or plastic items that came in contact with the animals. DATCP staff will then disinfect those articles with a strong chlorine bleach solution. In areas or heavy animal traffic, the owner will need to scrape off and bury 2 inches of topsoil and replace it.

If no more animals from Sperber’s farm test positive, he could re-introduce elk or other cervids such as deer after a year. He may use the property for other species in the meantime.

Sperber will receive both federal and state indemnity payments for the animals. The federal indemnity totals 95 percent of the appraised value of the animals. The state indemnity will pay two-thirds of the remainder or $1,500, whichever is less. The U.S. Department of Agriculture will pay disposal costs, which will depend on how many, if any, of the animals test positive.

The test results will also help determine the fate of four other elk herds quarantined because they contain animals that came from Sperber’s herd.