1. Investigating Herd Mastitis Problems Dave Wolfgang Bhushan Jayarao Ernest Hovingh Department of Veterinary & Biomedical Sciences Penn State University Dave Wolfgang Bhushan Jayarao Ernest Hovingh Department of Veterinary & Biomedical Sciences Penn State University

2. 2 The plan  Defining the problem  Who?  When?  What?  Why?  Where?

3. 3 “Over-the-phone” questioning  Herd description  Size  Housing  Milking facilities  Herd veterinarian(s)?

4. 4  What is the problem - from the producer’s point of view?  High bulk tank SCC??  How high?  Too many cases of clinical mastitis?  How many?  Cows dying due to mastitis?  How many? “Over-the-phone” questioning

5. 5  What records/information do you have available?  DHI individual cow SCC?  Clinical mastitis / treatment records?  Culture results?  Milking equipment analysis?  What has been done to date? By whom?  Vet, equipment dealer, pharmaceutical company rep, consultants, etc. “Over-the-phone” questioning

6. 6 Can I get... ...your DHI herdcode & RAC? ...a copy of any other records & information (clinical mastitis/treatment records, etc.)? ...your vet’s (and other relevant peoples’) contact information? ...you to send in some bulk tank samples?

7. 7 DHI Records Analysis  Regarding SCC...  Cows with >200,000 somatic cells/ml – high probability of being infected  200,000 = LS 4  SCC of cows that have been successfully treated should return to <200,000 within ~1 to 4(+?) weeks  Not all high SCC will show up as clinical mastitis

8. 8 DHI Records Analysis  Summary information  eg. DHI 802

9. 9“Goals” Linear Score <5.0 Linear Score >7.0 1 st lactation > 90% < 2% 2 nd lactation > 85% < 4% 3 rd+ lactation >80% < 5% Whole herd > 85% < 4%

10. 10 How ‘clean’ are the heifers “on average” entering the herd? What is “on average” the change in SCS over the dry period? How many animals is this an average of? Are these the same animals?

11. 11 DHI Records Analysis  On-line course developed by PSU (http://onlinelearning.psu.edu/DHIA/)  SCC spreadsheet being developed by Dave Baver & Rob Goodling  Individual cow SCC

12. 12 DHI Records Analysis

13. 13

14. 14 Records analysis  Clinical mastitis cases per month  “Goal”: <3 cases per 100 cows per month  Records are usually of ‘tenuous quality’  Obviously depends on ‘case definition!’

15. 15 Records analysis  Treatment/therapy & ‘cure’ records  Non-existent on most farms, or unreliable

16. 16 Records analysis  Use/analysis of records prior to a herd visit will:  More clearly identify the problem  Help guide the farm investigation  Make it look as if you know what you’re doing

17. 17 QUESTIONS? COMMENTS?, eph1@psu.edu