LAKEWOOD, Colo. (AP) — Colorado agriculture officials say they plan this week to release the quarantine on a dairy herd whose cows were diagnosed with bovine tuberculosis in April.

The cows were diagnosed in April.

The Colorado Department of Agriculture said Tuesday that tests showed a "significant level" of infection within the 500-cow southern Colorado herd, but that the premises have been disinfected.

Agriculture officials also have been tracing the movement of livestock that were at the operation before the quarantine.

The 500 cows were killed but officials say no meat from infected animals ever reached the human food chain, and there is no public health concern from pasteurized milk. Commercially sold milk is pasteurized.

Copyright 2010 The Associated Press.