N. Idaho company checks large game for pregnancy

COEUR D'ALENE, Idaho — Adult female bison don't take kindly to traditional pregnancy tests.

The test, known as "rectal palpation," involves a veterinarian inserting a gloved arm to feel for thickening in the uterus wall. In hormonal beasts weighing nearly 1,200 pounds, the test can quickly become a recipe for injuries.

"Buffalo are tremendously fast and strong," said Dr. Kenneth Throlson, a retired vet who owns a North Dakota bison ranch. "They go from docile to crazy in about two snaps of the finger."

About seven years ago — after two hip replacements, back injuries and shoulder troubles — Throlson switched from manual pregnancy testing to blood tests for the ranch's 300 bison cows. Blood samples are sent to BioTracking LLC in Moscow, Idaho, for processing. Within 27 hours, ranch hands know which bison are pregnant.

"If we get the samples today we can tell the farmer tomorrow in the afternoon," said Dr. Garth Sasser, BioTracking's president. "Our tests are 99 percent sure if we say she's not pregnant and 93 to 95 percent correct if we say she is pregnant."

Sasser and colleagues at the University of Idaho originally developed the test for cattle in the 1980s. While domestic livestock accounts for the bulk of the company's sales, pregnancy tests for wildlife and farm-raised game are on the rise.

Last year, BioTracking processed about 3,200 pregnancy tests for bison, elk, moose, deer, big horn sheep and exotic deer animals known as "ruminants" because of their multichambered stomachs. The tests cost about $20 per animal.

In Oregon, Wyoming and Idaho, the blood tests are being used in research to determine whether wolf packs and ATVs are affecting pregnancy rates in wild elk herds. At ranches such as Throlson's bison farm, the tests play an important role in herd management.

Producers need to know as quickly as possible if their animals are pregnant, Throlson said. Expectant mothers are put out to pasture, while infertile bison are fattened up for slaughter.

"There's no free lunch," Throlson said. "If a cow is not going to have a calf, you turn her into cash in the form of meat."