A study of 27 of the state's feed manufacturers shows about a quarter of them committed some major violations.
The Colorado Department of Agriculture says they violated rules designed to prevent Mad Cow disease.
The biggest problem?
Many of the companies failed to properly label animal feed containing meat and bone meal from slaughtered cows.
The feed could contain Mad Cw disease and be inadvertantly fed to animals.
The study also shows some companies did not keep records of who purchased feed containing meat.
Such records would help investigators track down the cow if it tested positive for the disease.