I Don't Have Brush For That
We are checking for a source of bacteria contamination of post-pasteurized milk from nursing bottles. Only the very youngest calves are fed with bottles with the remainder learning how to drink from buckets before they are a week old.
The milk coming out of the pasteurizer is clean - all the samples that we culture have no growth at 48 hours - none, zip.
When we collect and culture "as-fed" samples from nursing bottles they are alive with bacteria. This dairy has a history of doing a good job of cleaning milk feeding equipment. Thus, these culture results are puzzling.
Where is the contamination coming from? First, I thought that the contamination was coming from the sampling process - something like dirty hands, thumb on the inside of the sample bottle lid. Nope. Put on clean nitrile gloves when collecting samples.
Then we checked the inside surfaces of bottles - nope. Highest reading using the ATP luminometer was 6 RLU's. [For reference, the food industry standard for clean is <10 RLU's.]
I asked for a nipple to check the inside surface. I swabbed up inside the nipple part, not the cap. RLU reading was 580! Oops. When I asked about brushing bottles and nipples I found out that they had a good bottle brush but nothing with which to brush up inside the nipples.
The solution was pretty simple - I pulled a double-end brush out of my truck and the dairy was in the business of brushing the insides of the few nipples they use to feed the youngest calves.
Click HERE to see a picture of this brush.