A review of: Measuring effectiveness of teat preparation
Review of research regarding how teat cleanliness can be assessed quickly and objectively.
A review of a paper Presented at the 2003 National Mastitis Council Meeting
by A. Johnson, P. Rapnicki, R. Farnsworth, S. Stewart,
R. Salter, C. Sigurdson, L. Adkins and S. Burnell
Teat cleanliness at milking can impact bulk tank bacteria counts as well as mastitis. Dirty teats force milkers to spend more time cleaning which slows down the milking routine. Milking units should always be attached to clean, dry teats. The question is how can teat cleanliness be assessed quickly and objectively.
Researchers in Minnesota reported on their efforts to use ATP bioluminescence sensing as a method to determine teat and teat end cleanliness. The ATP bioluminescence technology is being used by the food processing and health care industries as a quick method to determine the cleanliness level of work surfaces. The meat processing industry is evaluating its use to evaluate carcass cleanliness and bacteria numbers.
The concept is based on the fact that all biological systems contain ATP as their energy source. This includes bacteria, somatic cells, and other biological systems. Therefore, if a surface is tested and shows high levels of ATP it is soiled and if the level is low it suggests less contamination. The question is always what is low and what is a normal background level for the surface being evaluated. The ATP test is not a true measure of bacteria levels but a measure of the total soil load on the surface being tested, which includes bacteria.
ATP testing works best when the conditions of use including location tested and type of surface are standardized as much as possible. Use on teat skin presents a challenge due to significant variation that is tough to control.
When the ATP technique was tested on cows and compared to traditional teat swabs and bacteriology methods the correlation was not strong between the results from the two methods. A swab that showed low bacteria counts might still show high ATP values. Therefore these two methods are not likely to be strongly correlated because they are measuring somewhat different things.
When used to determine teat cleanliness before and after cleaning the ATP test did register an appropriate reduction in ATP values and so may be able to reflect improved teat cleanliness.
The ATP test may have application in testing teat skin cleanliness but users must understand what represents acceptable values and what are normal background values. The large amounts of variation in this environment will require further evaluation and development of a standard test protocol before the method can be used reliably to produce meaningful results.
The National Mastitis Council