Successful drying off is much more than just treating cows
The method used to dry-off cows
can significantly influence how many udder infections
establish during the dry period. The aim is to shut
down milk secretion and seal the teat canal as rapidly as possible – this
usually takes about two weeks. Most new infections occur in quarters where the
teat canal has not sealed.
The
Countdown Downunder Farm Guidelines for Mastitis Control (Guideline No. 16)
gives practical recommendations for successfully drying off milking cows with
the minimum risk of infection. These recommendations are summarised below.
1. Dry-off cows as soon as their production reaches 5 litres or less per day.
A cow
producing less than 7 litres/day is trying to dry herself off. Continued milking
of these cows prevents teat plug formation and makes them more prone to new
quarter infections. Cows producing less than 5 litres/day may significantly
increase bulk milk cell counts (BMCC), even when they do not have mastitis, due
to cells concentrating in the reduced volume of milk.
2. Cease milking cows producing 12
litres or less per day at drying-off
3. Take steps for cows producing
more than 12 litres to reduce production to 12 litres or less by the drying-off
date. These steps involve reducing food intake and changing routine
Farmers should plan for drying-off – generally allow at least
one week’s lead-time before the drying-off date.
Cows that are still producing more than 12 litres of milk
near drying-off time require special management if they are to spend 6-8 weeks
dry and attain their production potential in the following lactation. Countdown
recommends the following procedure to reduce yields for drying off –
One week
prior to the final milking
·
Take high-producing cows off concentrate feed
Three days
prior to the final milking
·
Move to a paddock with very little feed
·
Reduce feed intake to maintenance level (about 7-8 kg of hay for a 500 kg cow)
·
Separate the cows from the main herd if practical
·
Change the routine of milking for cows to be dried off – eg. graze in different
mobs, and bring to the dairy via an alternative route if possible.
Remember that
animal welfare codes require water to be always available.
4. Dry-off abruptly; do not skip days and preferably do not skip milkings.
Cows should be
milked as usual at each milking until drying-off (do not deliberately leave milk
in the udder). Intermittent milking provides a stimulus to produce milk and
impedes sealing of the teat canal. The risk of mastitis is greatly increased if
cows are milked every second day.
5. Don’t
leave cows in laneways or yards immediately after drying-off.
6. Put
the cows in a dry, clean paddock (not heavily soiled with manure, no bare
ground, no exposure to dairy effluent) for 3-4 days after drying-off.
It is important
to minimise the number of bacteria on teats by teat dipping after the last
milking and not allowing cows to lie down on bare ground or areas that are
soiled with manure in the two hours immediately after Dry Cow Treatment is
given. Cows are particularly susceptible to infection until the teat plug forms.
7. Continue the ‘maintenance only’
diet for another 3-4 days for cows that were producing 12 or more litres/day in
the week before drying-off.
Milk leaking from
the udder, particularly under pressure, will impede the development of the
keratin plug and increase the chances of infection. It is often useful if
recently dried off cows are kept in a paddock well away from the milking herd
and milking area to reduce the possibility of triggering milk ejection.
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