Teat sealant

What is a teat sealant?

A teat sealant closes the teat canal during the dry period. There are two types:

• Internal teat sealants are a paste, usually based on bismuth subnitrate, inserted into the teat canal and teat cistern after the last milking. The paste stays there until calving.
• External teat sealants form a film on the teat end, similar to a teat dip. They only last a few days.

Internal teat sealants are veterinary medicines and you get them through your vet. They contain no antibiotic, but work purely mechanically.

Why does the teat need protection?

After drying off, a natural keratin plug normally forms in the teat canal. In many cows, though, it closes late or not completely. In the first weeks of the dry period and shortly before calving, the udder is therefore especially vulnerable to new infections, mainly with environmental pathogens such as E. coli and Streptococcus uberis. Infections from this period often only show up as mastitis in the next lactation.

The internal sealant replaces this plug. It stops pathogens from entering through the teat canal.

Teat sealant and selective dry cow therapy

In the past, many cows were dried off with antibiotics as a matter of routine. Today the choice is made cow by cow. In the Netherlands, preventive dry cow therapy with antibiotics has been banned since 2014, and EU rules only allow preventive use of antibiotics in exceptional cases. A common approach:

• Cows with a cell count below 150,000 at the last milk recording, heifers below 100,000, with no clinical case during the lactation: internal teat sealant only.
• Cows above that or with mastitis during the lactation: dry cow antibiotic plus teat sealant, agreed with your vet.

This way only infected cows get an antibiotic, and the healthy ones are still protected.

Hygiene when inserting

A sealant locks in whatever is in the teat canal. If you insert it without proper hygiene, it carries the pathogens into the udder itself. That is why hygiene at drying off matters more than at any other milking:

• Milk the udder out and clean the teats thoroughly.
• Disinfect each teat end with its own alcohol swab until the swab comes away clean. Do the far teats first, then the near ones.
• Wear clean disposable gloves.
• Insert only the tip of the tube nozzle briefly into the teat canal.
• Do not massage the sealant up into the udder. It should stay in the teat. Pinch the base of the teat with your thumb and forefinger to keep it there.
• Dip afterwards.

Keep the cows standing after drying off and move them to a clean, dry environment.

After calving

The sealant is not absorbed by the body. It is stripped out during foremilking at the first milkings after calving. Remnants can appear as grey strands in the milk. Strip the teats thoroughly for the first few days. On a milking robot, separation of this first milk should be set up.

Checks during the dry period

Look at the udders every day in the first week after drying off. A hot, hard quarter or a cow with a fever needs the vet. Provide a dry, clean lying area, in the calving pen too.

Frequently asked questions

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