Internal teat sealants

Internal teat sealants (ITS) have the ability to prevent mastitis in heifers and in cows, and is a well proven and widespread practice on many dairy farms.

The decision if to use ITS is one worth taking time to consider. Many cows are dried off with combination therapy - insertion of both an antibiotic dry cow therapy (DCT) combined with use of an ITS. The antibiotic DCT cures existing infections and the ITS stops new ones from establishing over the dry period. But what about those cows that are not infected at drying off? Do they need that antibiotic? The short answer is, if there is no infection to treat, all we need to do is prevent new infections from establishing, and using an ITS is the most effective way of achieving that.

Firstly, what is an "uninfected" cow? We actually don't know if a cow is infected or not unless we run a milk culture on every cow at drying off. Therefore we use the cow's mastitis and somatic cell count (SCC) history. Combined, those two pieces of information are very accurate at sorting infected cows that should be treated with antibiotic DCT from uninfected cows that don't need antibiotic DCT. So by "uninfected" cows, we mean cows that did not have clinical mastitis and whose SCC did not exceed a threshold (typically 150,000 cells/ml) during the season.

Numerous trials from New Zealand (NZ) and overseas have demonstrated that using an ITS alone in uninfected cows roughly halves their mastitis rate next spring, compared to no treatment. Use of an ITS was also shown to be as effective as long acting antibiotic DCTs in uninfected cows.

ITS prevents mastitis until it is removed by suckling or stripping at first milking. Most NZ cows are dry for much longer than the length of cover offered by the longest acting antibiotic DCT. Relying on antibiotic DCT alone means your cows are most likely unprotected during the period of highest risk for mastitis infections establishing - as they bag up and calve.

So should you use an ITS alone in your uninfected cows? It depends on your farm's mastitis pattern. You should consider it if:

  • You want to protect your cows for the entire dry period
  • You have little contagious mastitis circulating through your herd
  • You want to minimise antibiotic use
  • You want to minimise inhibitory substance risk
  • You want to save money on unnecessary combination therapy
  • You have herd test results (ideally at least two) and good mastitis records

Don't hesitate to discuss the options with your vet and whether using an ITS is appropriate in your herd. Lastly, whether it is in cows or heifers, you're using antibiotic DCT or an ITS, hygiene is paramount! We have a great team of technicians that, if required, can provide expert advice and additional hands on support during the drying off process so give the clinic a call today to book your herd in!