Antimicrobial resistance (AMR) is one of the biggest challenges we are facing in the dairy cattle. The new Veterinary Medicine Regulation will force dairy farmers from blanket dry cow therapy to selective dry cow therapy, which generally allows a prudent and reduced use of antimicrobials in dairy cows.
As discussed previously1, somatic cell count (SCC) is one of the key elements that drive the decision-making process for selective dry cow therapy at herd level. Specifically, are SCC and mastitis issues under control? At least, the followings have to occur:
- bulk tank SCC constantly below the reference value of 200,000 cell/ml in the current lactation;
- contagious mastitis pathogens (Staphylococcus aureus and Streptococcus agalactiae) under control;
- no infections (including subclinical issues) at the time of drying-off;
- no clinical mastitis events during current lactation.
Measuring the bulk tank SCC (BTSCC) gives an idea of the quality of the milk. It is generally recognized by the law as a specific parameter to comply with for milk delivery. If we want to know the prevalence and incidence of subclinical mastitis at cow level and, thus, to understand the udder health status and cow’s eligibility to a selective dry cow procedure, we also need to measure individual SCC.
However, BTSCC is also useful to understand globally the herd health status. Generally, BTSCC constantly below the threshold value (200,000 cell/ml) can indicate healthy herds. Regular monitoring and recording both of BTSCC and individual SCC allow an efficient mastitis control.
On the other hand, measuring individual cow SCC regularly over each lactation is the best practice to monitor the udder health in each cow. We can consider individual SCC an essential parameter for management decisions, allowing us to exclude those animals not eligible for selective dry cow therapy.
For an improved implementation of a selective dry cow procedure, we may also consider checking SCC at a single quarter level. When the cow shows SCC values higher than the threshold value (200,000 cells/ml) during the last 3 months before dry-off, we have to consider antibiotic treatment in all quarters with our vet. If not, and no clinical events have occured in this period, we will check each quarter for SCC.
It is possible that, during lactation, the cow has experienced udder issues in only one quarter. Using the information collected, considering also farm practices and with lab tests per individual quarter right before dry-off, we can understand which quarter needs to be treated with antibiotics.
In those quarters with no issues, we can use OZOLEA-MAST: where antibiotics are not needed, the advantage of OZOLEA-MAST lies in the maintenance of a contained SCC count at the third and fourth month after calving. For this specific application, OZOLEA implemented Protocol M9 (M9. Udder at dry-off: selective dry cow treatment quarter by quarter).
Dry-off and the dry period are very delicate moments in a cow’s life because, if something does not work, future lactations as well as the life of cow and calf are at risk. Accordingly, veterinary advice is required also for the application of this protocol and for the evaluation of the results. What local authorities suggest with regard to dry cow therapies is to be taken into account as well.
1 Blanket dry cow therapy, ban on prophylaxis from January 2022. Any alternative? Selective treatment.
