Veterinarians can help dairy producers reduce costs associated with mastitis by using pathogen-based management decisions and potentially by treating for shorter intervals targeting actual bacterial infection rather than inflammation. In a webinar this week, sponsored by Boehringer-Ingelheim Vetmedica (BIVI) and hosted by Bovine Veterinarian and Dairy Herd Management, veterinarians Linda Tikofsky with BIVI and Daryl Nydam at Cornell University outlined some recent research influencing current thinking on mastitis treatment.
Tykofsky notes the difference between infection and inflammation in mastitis cases. Depending on the pathogen, the infection stage usually is short, lasting just a few days. Signs of inflammation resulting from the infection, including high somatic-cell counts, can persist for several days longer. Treatment protocols based on the time it takes for milk to return to normal, or on visible inflammation in the affected quarter, could last longer than necessary.
Nydam, who leads Cornell’s Quality Milk Production Services, says two Cornell studies, results of which are published in the Journal of Animal Science, indicated that a three-day treatment with Polymast (hetacillin potassium) provides results equal to a five-day treatment with ceftiofur hydrochloride. Both treatments used one tube every 24 hours for the duration of the treatment.
Nydam says Cornell research also has shown that pathogen-based therapy, using cultures to identify mastitis pathogens and guide treatment decisions, can provide up to $30,000 per 1,000 cows in annual savings while also addressing consumer concerns over antibiotic use. Pathogen-based therapy can allow managers to leave some cattle untreated and use lower-cost treatments on some cattle, with lower treatment costs and less waste milk contributing to the cost savings.
A pathogen-based approach can use on-farm cultures to characterize infections within 24 hours. If a dairy sends samples off-farm for culturing and analysis, Nydam says they could use shorter-duration therapy as the initial protocol, then review culture results for subsequent treatment decisions. Culturing samples also provides an ongoing record of pathogens most frequently present in the herd.
Tykofsky outlined another recent Cornell study, which will appear in the Journal of Dairy Science. This trial again compared treatments with Polymast for three days, one tube per day, with ceftiofur hydrochloride tubes once per day for five days. For the test, the team identified 627 cows from six herds exhibiting mild to moderate clinical mastitis, and randomly sorted them into treatment groups.
Trained workers evaluated the cattle daily and assigned clinical mastitis scores from day one through day four. They also collected milk samples for cultures at days 14 and 21, and followed the cattle for recurrence out to 60 days. Outcomes included bacteriological cure, meaning the initial pathogen is absent following treatment, pathogen cure, meaning no growth in the target pathogen and clinical cure, meaning milk and the affected quarter return to normal within five days.
Overall bacteriologic cure was 71% in the study, with no significant difference between the Polymast and ceftiofur hydrochloride treatments. Gram-positive cure risk was 63% for Polymast and 70% for ceftiofur hydrochloride, while cure risk for Gram-negative pathogens was 79% for Polymast and 82% for ceftiofur hydrochloride. Again, the differences were not significantly different. A higher percentage of the Polymast cows (70%) experienced a clinical cure in less than four days compared with ceftiofur hydrochloride cows at 59%. There was no significant difference in extended clinical cure.
In this trial, there were no significant differences between the two treatment groups for post-event milk yield, post event linear score, survival to 30 or 60 days or mastitis recurrence in the same quarter. Hospital days for the Polymast group, at an average of 6.2, were lower than those for the ceftiofur hydrochloride group at 8 days.
The Webinar now is available for on-demand viewing.