As the weather is particularly mild and has turned damp in the last number of days, fly control to prevent summer mastitis needs to be prioritised.
Summer mastitis is an acute disease of the non-lactating mammary gland and is mainly caused by the bacterium Trueperella pyogenes.
Flies thrive in these conditions, especially in the aftermath of heavy rain when temperatures are warm and can support fly populations, as the insects can multiply in those conditions.
This is not good news for in-calf heifers down the other side of the farm as their teat ends become a target for the flies to feed off.
Quite often, heifers will be on the wetter paddocks of the farm – paddocks that are possibly not suitable for intensive grazing on the milking platform. This swampy, damp ground can attract a lot of flies and cause issues for these heifers.
Summer mastitis often hits the same herds each year and quite often the source of the problem comes from certain fields.
The disease mainly occurs in the June to September period affecting dry cows and in-calf heifers when fly numbers are highest, but can really occur at any time of the year and especially in mild and damp conditions.
Summer mastitis
The disease can severely damage the udder, cause high temperatures and toxaemia, and the infected quarters are generally lost. Treatment is focused at saving the animal and preventing pregnancy loss.
The quarter becomes hard and and swollen and when it is stripped, it will be foul-smelling and the cruds that come out may appear clear or soft to cheesy. As the infection progresses, blood may be drawn.
If the condition is not as advanced, the infected quarter should be treated with intramammary tubes and the cow placed on a course of antibiotics.
In more severe cases, the cow or heifers should be placed on a course of anti-inflammatory drugs and in some cases, the vet will opt to amputate the teat to allow it to drain freely.
In all cases, the cows’ affected quarter should be frequently stripped out to reduce toxin build-up and the cow isolated from the group.
Prevention
Using dry cow tubes for more susceptible heifers might be an option but severe care and hygiene is needed so that dirt is not introduced to the teat canal or the teat end is not damaged.
The use of teat sealers are also brilliant to minimise the disease, as the teat seal plugs the teat, preventing bacterial transfer from the environment and flies, Teat sealers should be considered on heifers, even though you may need to organise a turn-over crate to get them done.
Using pour-on or other products to control flies near or around stock and to prevent summer mastitis is important. These products should be used as instructed to ensure maximum effectiveness.
Apply these along the back of the animal but no harm to direct some around the udder area as well. A number of these products will give cover for four weeks but may need to be applied more often if fly control proves difficult.
Ear tags containing Cypermethrin are also available for fly control, such as Flectron tags, which come in boxes of 10. Once one tag is put into the cow’s or heifer’s ear, they are immediately effective and have a duration of four months.
Using Stockholm tar around the teats and udder at least once a week will help prevent flies, but in order for it to be effective, it has to be applied regularly.
Fields that are well-kept, with tight residuals and topping reduce habitat where flies can thrive, therefore reducing the risk.
Also, it is important to avoid letting dry cows and in-calf heifers in fields that have a history of summer mastitis, typically where there is marshy ground, near a river, or has large quantity of trees and hedges.
