Drying Off Your Dairy Cows: A Guide to Dry Cow Therapy and Teat Sealing 

Drying off is one of the most important management events in the dairy calendar. Done well, it protects udder health, sets cows up for a successful calving, and pays dividends in milk quality and production right through the following season. Done poorly, it is one of the most common causes of mastitis and elevated somatic cell counts (SCC). 

For Canterbury dairy farmers, the dry period typically falls across winter – which means the decisions you make at dry-off are happening right now, and the outcomes will show up at calving in spring. 

This guide covers what you need to know: when to dry off, which approach suits your cows, and how dry cow therapy and teat sealing work together to protect your herd. 

Why the Dry Period Matters for Udder Health 

The dry period serves two purposes. First, it gives the cow’s body a chance to recover, rebuild body condition, and prepare for calving. Second, it is a critical window for the udder – existing infections can be treated, and new infections can be prevented before the cow returns to the milking herd. 

Research consistently shows that the majority of new intramammary infections that affect the following lactation are acquired either at dry-off or in the lead-up to calving. Getting dry-off right is therefore not just about this season – it directly influences how the next season starts. 

When Should You Dry Off? 

Most Canterbury dairy herds dry off cows six to eight weeks before their expected calving date. This window allows enough time for: 

• The udder to fully involute and clear any existing low-grade infections 
• Body condition to be restored, particularly in thin cows 
• The immune system to be well-supported ahead of the metabolic demands of calving 

Cows that are dried off too close to calving have a shorter recovery window and are at greater risk of transition disease and mastitis at calving. If you have cows that are still producing significant volumes of milk at the time of dry-off, discuss a managed dry-off approach with your vet – abrupt dry-off in high-producing cows carries a higher risk of new infections. 

Dry Cow Therapy: Blanket vs Selective 

Dry cow therapy (DCT) involves treating cows at dry-off with an intramammary antibiotic product, a teat sealant, or both. There are two main approaches used in New Zealand dairy herds. 

Blanket Dry Cow Therapy 

Blanket DCT means every cow receives an antibiotic dry cow tube at dry-off, regardless of her SCC or mastitis history. This approach has been used for many years and remains appropriate for some herds with high bulk milk SCC, or a history of severe clinical mastitis. Using blanket dry cow therapy does not lower bulk milk SCC in subsequent seasons. 

Moving forward, an important consideration is responsible antibiotic use – New Zealand’s veterinary guidelines increasingly emphasise using antibiotics only where they are clinically indicated, which is why selective DCT is becoming more common in well-managed herds. 

Selective Dry Cow Therapy 

Selective DCT means making individual cow decisions based on data – SCC history, mastitis records, milk testing results, and your lead vet’s assessment. Cows identified as low risk receive a teat sealant only, while those with a history of mastitis or elevated SCC receive antibiotic treatment as well. 

This approach requires reliable herd records and a good working relationship with your dairy vet. When done well, it maintains strong udder health outcomes while reducing antibiotic use across the herd. Your Aorangi Vets lead vet can help you assess whether selective DCT is appropriate for your herd and how to implement it. 

Teat Sealing at Dry-Off 

Teat sealing is now a well-established part of dry cow management in New Zealand, used both at dry-off and in pre-calving heifers. 

At dry-off, a teat sealant – most commonly Teatseal – is inserted into each teat canal immediately after the final milking. It forms a physical barrier that mimics the natural keratin plug, blocking environmental bacteria from entering the udder during the dry period. 

Teat sealants are used: 

• Alone in low-risk cows in a selective DCT programme 
• In combination with antibiotic DCT in higher-risk cows, to protect both against existing infections (antibiotic) and new infections during the dry period (sealant) 

NZ research has shown that teat sealing at dry-off significantly reduces new intramammary infections acquired during the dry period. For herds that have already benefited from heifer teat sealing before calving, the approach is the same – a physical barrier against environmental pathogens during a vulnerable period. 

It is important that teat sealants are inserted correctly and hygienically. Aorangi Vets offers on-farm dry-off support and can assist with teat sealing as part of your dry-off programme. 

Managing Somatic Cell Count Around Dry-Off 

Somatic cell count (SCC) is one of the most useful indicators of udder health in your herd. Cows with persistently elevated SCC heading into dry-off are carrying infections that, if untreated, are unlikely to resolve on their own during the dry period. 

Key considerations for SCC management at dry-off: 

• Identify high-SCC cows early – ideally several weeks before dry-off so you have time to plan treatment 
• Consider culling decisions – cows with chronic high SCC and repeated mastitis history may not be worth carrying through another dry period 
• Discuss antibiotic selection with your vet – the right DCT product depends on the bugs causing problems in your herd, which can vary between properties and seasons 

Herd testing data is invaluable here. If your herd is not on a regular testing programme, talk to your Aorangi Vets dairy vet about getting a baseline picture of udder health before dry-off. 

Practical Tips for Dry-Off in Canterbury 

Winter dry-off conditions in Canterbury add an extra layer of management consideration. Wet paddocks, muddy laneways, and cold conditions increase environmental bacterial pressure on freshly dried-off teats in the hours and days after their last milking. 

A few practical steps that make a real difference: 

• Teat spray thoroughly at the final milking and for the first few days after dry-off to reduce bacterial load on teat skin
• Move dried-off cows to clean, dry areas away from high-traffic muddy paddocks where possible 
• Monitor for signs of discomfort in the first week after dry-off – swelling, heat, and hardness in quarters can indicate a problem developing 
• Do not milk out cows after dry-off unless there is a welfare concern – this disrupts the natural involution process and removes the protection offered by teat sealants 
• Keep detailed records – note which cows received antibiotic DCT, teat sealant, or both, and ensure withholding periods are recorded and observed 

Working with Your Aorangi Vets Dairy Team 

Getting dry-off right is not a one-size-fits-all exercise. The best outcomes come from a planned, individual herd approach – one that takes into account your SCC history, mastitis records, calving pattern, and farm system. 

Your Aorangi Vets lead vet can help you: 

• Review herd SCC data and mastitis records ahead of dry-off 
• Decide between blanket and selective dry cow therapy 
• Select the right antibiotic and teat sealant products for your herd 
• Plan heifer teat sealing ahead of calving 
• Set up a dry period monitoring programme to catch problems early 

Get in touch with your nearest clinic before dry-off begins – the earlier you plan, the better the outcomes at calving.  

Ready to plan your dry-off programme? 

Talk to your Aorangi Vets dairy team before the season gets away on you. 

Timaru: 03 687 9378 | Geraldine: 03 693 1163 | Fairlie: 03 685 8407 

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