Assessment of the herd MAP bio-burden is a relatively new method of monitoring effectiveness of herd management practices, especially culling of the most infectious MAP positive cattle on the farm. Two primary methods are deemed appropriate; a) culture of environmental manure samples from high cow traffic areas such as walk ways, feeding areas and milking parlor entrance; b) culture of 1 to 5 pools of manure samples from all adult cows.

Objective

To compare the results of composite environmental manure samples from high cow traffic areas to composite manure sample of all adult cows in the herd.

Materials and methods

Individual fecal samples from several known MAP infected herds have been cultured and pools of 1:5, 1:10, 1:50, 1:100 and then the entire herd have been cultured for MAP. These larger pool sizes have been compared to composite environmental manure samples. Typically 4-6 manure samples from high cow traffic areas are mixed together for one composite sample. Then, the 6 to 8 composite samples environmental sample culture results are compared to the entire herd composite in addition to individual cows MAP cfu.

Results

To date composite herd fecal pool MAP cfu correlates well with MAP cfu from environmental fecal samples. Removal of super-shedders reduces both the herd composite MAP cfu and environmental MAP cfu. One herd had three composite environmental samples with 100 cfu/tube with a herd culture prevalence of 3.2% (4 pos/125). One super-shedder cow contributed to this massive environmental contamination.

Conclusion

Pools with all adult cattle in a herd offers quantitative assessment of MAP cfu from the entire adult herd that is not available when culturing individual cows. Composite environmental fecal samples offer a second method to verify the extent and to quantify the environmental MAP cfu bio-burden.

Sponsorship

This project was supported in-part by the USDA-ARS-RDQMA project.