Selective dry cow therapy (SDCT) is a decision made at dry off about whether your cows receive antibiotic dry cow therapy (ADCT) in addition to a teat sealant such as OrbeSeal®.
Milk purchasers in mainland GB are starting to monitor the antibiotic usage in the herd, particularly at dry off, and therefore cows that do not need the antibiotic may only require the teat sealant. But how do you know which cows are suitable for OrbeSeal® alone?
The best person to advise you on this is your vet. They will take into account your farm situation such as bulk milk cell count, clinical mastitis rate and any milk sample bacteriology results that you have. They will then create a list of cows that are uninfected and cows that are infected which you should use alongside the knowledge about your individual cows to make a final decision for each animal. Cows that receive OrbeSeal® alone should be free from infection at the time of dry off and at low risk of acquiring infection over the dry period.
It is more straightforward to explain which cows are likely to be infected at dry off:
High SCC cows
Cows that have had a case or multiple cases of mastitis during lactation
Cows with a positive California Mastitis Test (CMT) at dry off
This means that cows that have not had a case of mastitis during lactation, are low cell count towards the end of the dry period (for example the last three readings prior to dry off) and are CMT negative at dry off may be suitable for drying off with OrbeSeal® alone. The rest of the cows could be infected at the time of dry off and should receive antibiotic in addition to OrbeSeal® at dry off.
Cows that are at higher risk of acquiring mastitis during the dry period include:
Cows that leak milk after dry off
Cows with a higher yield at the time of dry off (> 15 L)
Cows with teat end damage
Cows that will go to a wet or dirty environment, for example if they will be outside and the weather has been poor
Cows that have dirty udders and teats at the time of dry off
Older animals that have had multiple lactations or very high yielding animals
The cows that are at higher risk of acquiring infection should receive an antibiotic in addition to OrbeSeal® at the time of dry off.
When faced with the prospect of selective dry cow therapy talk to your vet about how to make the decision and take into account your farm situation when deciding which cows should receive OrbeSeal® alone and which antibiotic should be used alongside OrbeSeal® for the rest of your animals. The more information you have the more accurate you will be with ensuring the right cows receive the right drying off therapy and the less risk you will be taking. Remember, when using any dry cow therapy that following the optimum infusion technique is essential for the best results.
Whilst Selective Dry Cow Therapy has not been imposed as yet in Northern Ireland, there is no doubt that changes will come in the future in this part of the world as well.