Bovine Tuberculosis in Michigan Cattle

1. Bovine Tuberculosis in Michigan Cattle Michael VanderKlok DVM Michigan Department of Agriculture and Rural Development Animal Industry Division

2. 2013 Bovine TuberculosisSurveillance Summary for Michigan

3. TB in 2013 - MAZ • One small TB infected beef herd identified in Alcona county • Previously infected in 2000 • Herd depopulated • No evidence of TB being spread from the herd

4. Historic findings • Northern Lower Michigan • Highest incidence in and around DMU 452, Alcona County, and Alpena County • Transmission from surrounding TB infected wildlife populations

5. Prevalence of TB in Cattle And Deer1995 - 2013

6. 2014 MAAZ Circle Testing • Two TB infected wild deer • Presque Isle County • NW Montmorency County • Presque Isle/Cheboygan County circle areas • Approx. 38 herds to test • Testing includes 12mo age and older and all non-natural additions • Completed in next 6 months

7. 2013 Saginaw Co.TB positive dairy herd TB positive beef herds associated with the Saginaw herd TB

8. 2013 Infected Herds – TB Free Zone3 TB Infected Herds & 1 Infected Feedlot

9. 2014 Infected Herds – TB Free Zone1 tb infected feedlot • Was part of trace investigation from Saginaw TB investigation • Determined to have possibly purchased exposed cattle that would now be reaching slaughter weight • Identical TB genetic type as the Saginaw dairy herd • Will result in 3 mile circle designation as the likely source of disease is purchased cattle, not wildlife

10. Saginaw Dairy herd • February 2013 – Adult dairy cow with lesions of TB identified at Michigan slaughter plant • Early March 2013 – Source dairy herd tested. 18% of cattle responded to the test. Herd designated as TB infected. • March through June 2013– Massive effort to find animals sold from the herd, get them to the lab, and test exposed herds. Efforts hampered by lack of records and lack of use of RFID eartags. • *Investigation also includes herds that may have fed unpasterurized waste milk to non-associated calves. • May 2013 – One small beef herd in Midland county and one livestock dealer herd in Gratiot county designated as TB infected. Both purchased cattle from the Saginaw dairy herd. Investigation and response expands. • September 2013 – Medium size feedlot in Arenac County designated as TB infected. Purchased cattle from the Gratiot herd. • March 2014 – Finished steer with lesions of TB identified at Michigan slaughter plant. Traced to feedlot that had purchased cattle from the Gratiot herd.

11. 2013/2014 TB Free Zone Infected HerdsInvestigation results • Saginaw Dairy Herd • Same strain type as cattle and deer in NE Lower Michigan • According to owner the most recent purchase of cattle into the herd was in the 1990’s • Three source herds all tested negative for TB • To date, all wildlife testing in the area negative for TB • Potential that TB was dormant in the herd for many years, and then became infective • Stress of heat and drought • High concentration of cattle • Stress of calving • High volume of unpasteurized waste milk fed to calves

12. 2013/2014 TB Free Zone Infected HerdsInvestigation results • Gratiot Livestock Dealer Herd • Same strain type as Saginaw dairy herd, and cattle/deer in NE Lower Michigan • Purchased cattle from highly infected dairy herd • Some of these were TB infected • Lack of Identifying animals • Lack of Records • Fed unpasteurized raw milk to calves (from multiple sources) • Calves from other sources were TB infected • To date, all wildlife testing in the area negative for TB • Herd has been depopulated

13. Animal Traceability and Disease investigation involving TB in Lower Michigan • Exposed cattle investigations • Over 230 farms investigated • 83 farms TB tested • 15,000 cattle tested • Source cattle investigations • 3 herds/6,085 cattle tested • Circle testing • 166 farms investigated • Over 100 farms tested to date • Over 11,000 cattle tested to date

14. 2013/2014 TB Free Zone Infected HerdsInvestigation results • Midland Small Beef Herd • Same strain type as Saginaw dairy herd, and cattle/deer in NE Lower Michigan • Purchased cattle from highly infected dairy herd • To date, all wildlife testing in the area negative for TB • Herd has been depopulated

15. 2013/2014 TB Free Zone Infected HerdsInvestigation results • Arenac Medium Feedlot • Same strain type as Saginaw dairy herd, and cattle/deer in NE Lower Michigan • Potentially purchased cattle from the infected Gratiot livestock dealer herd • Upon inventory of animals on the farm, an RFID eartag from the Gratiot herd was scanned. The animal was removed for diagnostic testing and was TB infected. • Herd has been depopulated

16. 2013/2014 TB Free Zone Infected HerdsInvestigation results • Huron County Feedlot • Same strain type as Saginaw dairy herd, and cattle/deer in NE Lower Michigan • Was part of trace investigation from Saginaw TB investigation • Determined to have possibly purchased exposed cattle that would now be reaching slaughter weight • Identical TB genetic type as the Saginaw dairy herd • Herd is undergoing phased depopulation as animals reach slaughter weight Other TB infected animals may be in feedlots and would now be reaching slaughter weight.