Colorado agriculture officials say four ranch quarantines that were prompted by an outbreak of anthrax in cattle in northeast Colorado have been released.

   Colorado Department of Agriculture officials initially estimated the outbreak killed 60 cattle in Logan County this summer, but they have since revised that to about 55 cattle on four ranches.

   Agriculture officials had said Aug. 8 that a cow from a ranch where about 50 cattle had died was determined to have had anthrax. The ranch was quarantined, surviving cattle were vaccinated, and a veterinarian and ranch workers were given antibiotics.

   The three surrounding ranches also were quarantined, and each lost one animal to anthrax.

   State veterinarian Keith Roehr said Friday there have been no deaths in the past 30 days, and the outbreak is likely over.