Proper cleaning of calf-feeding equipment can't be stressed enough.
When it comes to calf bottle nipples, you should hand wash them with a brush, not in the dishwasher, advises Don Sockett, veterinary microbiologist at the Wisconsin Veterinary Diagnostic Laboratory. They will not get cleaned properly in the dishwasher, which can lead to high bacteria counts in the milk or milk replacer fed to calves. While manually washing nipples, check for any visible cracks and signs of wear and tear. Replace those that are worn. Cracked nipples can harbor bacteria.
For more information, read "Clean calf feeding equipment in six easy steps."