"Yellowstone National Park managers have rejected a plan to use air rifles to shoot the nation's last herd of purebred bison with so-called biobullets containing a vaccine against a cattle disease, in a decision that has riled the U.S. livestock industry."
"Roughly half of Yellowstone's 4,600 bison are estimated to have been exposed to brucellosis, a bacterial infection that can sometimes cause cows and bison to miscarry.
Worries that infected bison may endanger cattle in states such as Montana that border Yellowstone had prompted the powerful ranching lobby to endorse biobullets - absorbable projectiles packed with vaccine. They would cut disease rates among bison by as much as 35 percent over 30 years."
Laura Zuckerman reports for Reuters January 22, 2014.
Advertisement 
