Calves with Sam

Real Numbers Help Guide Actions

Best management practices are not always easy to communicate to workers on dairy farms.

Two recent experiences suggest that getting real numbers (quantifying) to describe a situation may help get the need for improvement across to persons responsible for dairy calf care.

I am using the Hygiena SystemSure Plus unit to do adenosine triphosphate (ATP) monitoring. The ATP test is a process of rapidly measuring actively growing microorganisms through the detection of adenosine triphosphate. An ATP monitoring system can detect the amount of microbial contamination that remains after cleaning a surface (for example, calf feeding equipment). 

Thresholds used in the food processing industry are less than10 RLU for direct food contact surfaces and less than 50 RLU for environmental surfaces. I have been using a reading of 100 RLU as realistic on-farm upper threshold for calf feeding equipment

On Farm A we were concerned with post-pasteurization of unsaleable milk being fed to calves. The source of contamination was hard to pin down. Back in April we brainstormed for all the places where bacteria could be coming from. One place we checked was the underside of the top of a milk transport tank - the tank was filled with pasteurized milk to feed the calves. BINGO! RLU reading of 6443!  We agreed that this surface would continue to receive regular attention in the future. A matching test in June resulted in a RLU value of 39. 

On Farm B we were concerned with inoculation of colostrum with bacteria during the collection process. Attention to teat preparation did not appear to decrease inoculation levels. Testing the collection bucket did not turn up contamination - RLU value of 29. I picked up the stainless steel lid and swabbed at the edge and under the gasket. RLU value of 2209! We agreed that in the future the gasket would be removed and cleaned as well as all surfaces of the stainless steel lid being scrubbed after each use.