Using a teat sealant at drying off could help farmers take control of the udder, improve cure rates and reduce the number of new infections picked up in the dry period, as Aly Balsom reports.
How confident are you every cow in your herd is forming an effective teat plug immediately after drying off?
This keratin plug is part of a cow’s natural defence against bugs taking hold in the udder, yet 50% of cows fail to develop this essential seal at the start of the dry period. About 20% of cows also fail to form a plug at all, leaving them wide open to infection.
Vet Dave Coombes, from Cedar Farm Practice, says this ineffective plug formation is one of the fundamental reasons why mastitis develops in the first month after calving and explains why using a teat sealant is so important.
He says: “Forty per cent of clinical mastitis in the first 60 days of calving is picked up in the dry period. If you look at the natural risk of mastitis in the dry period, it’s the highest in the first 10-14 days after drying off and the last seven to 10 days prior to calving.”
It is this period at the start and end of the dry period where the keratin plug really comes into play. However, it can take the plug several days to form after drying off and it can naturally start to disappear as the cow approaches calving.
“That means even if the plug forms it may take too long to form and will be most effective 10-14 days after drying off, which provides time for an infection to develop,” explains Mr Coombes.
Along with providing the cow with a metabolic and physical rest from milking, the dry period represents a golden opportunity to clear up existing chronic udder infections, so preventing any exposure to bacterial infection is vital to ensure an effective cure.
“It’s much more effective to cure infection in the dry period than during lactation, and a teat sealant acts to prevent the ingress of new infection,” says Mr Coombes.
A teat sealant has the consistency of toothpaste and acts ‘like a stopper in a bottle’. When applied correctly and hygienically into the teat canal at drying off it can form an effective barrier to infection. Mr Coombes says it also provides assurance a teat barrier will remain throughout the dry period.
Dr Martin Behr, technical manager for MSD Animal Health, says sealants significantly reduce mastitis risk.
“Using an internal teat sealant alone, across all cows at drying off, reduces the risk of mastitis post calving by 29% and when used alongside an (intramammary) antibiotic it can reduce the risk by 48%,” he says.
Using a sealant alone also reduces the risk of new intramammary infections developing in the dry period by 73%. Dr Behr says sealants indirectly help dry period cure rates when used in combination with an intramammary antibiotic.
“If you give cows an intramammary antibiotic at drying off it can cure existing infection, but you could cure and then get a new infection developing. So if you use a sealant on top you can cure and prevent new infections,” he explains.
As a result, using a sealant in the dry period could help reduce antibiotic use in lactation – something which will help meet growing global demand for responsible use of antibiotics. Using sealant alone on cows with low SCC could also be an option on farms looking to reduce antibiotic use. However, Dr Behr says antibiotics should always be used when necessary and targeted use should be considered on a farm by farm basis in discussion with a vet.
Dr Behr says results from the 2014 National Mastitis Survey show a significant proportion of farmers are missing out on the benefits of using a sealant, with 30% of 400 farmers surveyed never using a sealant, and 58% using them across all cows.
However, Mr Coombes stresses farmers should not 'lean on’ sealants. “You need dry cows to be well bedded and fed. However, even if you manage the environment well, you can still face problems and that’s linked to the formation of the keratin plug which is linked to yield. Higher yielders will be more at risk of poor plug formation,” he says.
Mr Coombes also recognises old buildings and labour pressures can mean sometimes dry cows are managed in less than ideal situations, resulting in bacterial challenge. Equally, at grass control over the environment can be lost, leading to increased risk. In such situations teats sealants help add an extra layer of protection.
“I believe teat sealants are relevant to all dairy farmers and there’s a case for all clients to use them on all cows at drying off,” he says.
Using a teat sealant across all cows at drying off has helped Mark Bradford reduce the number of cows recording a high somatic cell count (SCC) at their first reading, and reduce mastitis rates in early lactation.
About three years ago, more than 34% of cows at Avington Manor Farm were recording high SCC at their first milk recording, something Mr Bradford attributes to poor keratin plug formation.
“I didn’t think the keratin plug was there for long enough so we decided to use a teat sealant. It has helped the udder to be a lot healthier. Before, we were also getting a few calving with mastitis or developing mastitis later on,” says Mr Bradford, who manages the 350 cow Jersey herd.
An intramammary antibiotic and sealant are now used on all cows at drying off with close attention paid to cleanliness.
The farm has always focused on good environmental management during the dry period, however they are continuously striving to improve. As a result the team now clean and disinfect straw yards more regularly. A monthly SCC action list has also been drawn up with vet, Dave Coombes.
Now, fewer than 20% of cows have a SCC of more than 200,000cells/ml at their first reading, and clinical mastitis levels in the first month of calving are down. Mr Bradford says, as a result, costs have come down because he is using fewer intramammary tubes in lactation and more milk is going in the tank.
Sealants have also helped staff identify whether a calf has drunk colostrum due to the presence or absence of the sealant at first milking. This has ensured calves receive the colostrum they require and has been reflected in better calf health.