Drying Off
As cows near the end of lactation their milk quality changes. Milk from low-producing cows may cause processing problems for some dairy products. Cows producing less than five litres per day may have an elevated cell count even if uninfected. They may contribute to a higher Bulk Milk Cell Count, even though their milk volume is low. Udder infections during the dry period can be minimised by events at drying-off.The aim is to shut down milk secretion and seal the teat canal as rapidly as possible - this sealing usually takes about two weeks. Studies in New Zealand have shown that virtually all new infections occur in quarters where the teat canal has not sealed. Intermittent milking provides an on-going stimulus to produce milk and impedes teat sealing. If 'skip-a-day' milking is practised, mastitis risk is greatly increased.
During the first two weeks after drying-off, it is also important to minimise the number of bacteria that contaminate the teats. Teat dipping after the last milking ensures complete coverage of the teat by disinfectant and reduces the number of cow-associated mastitis bacteria present on the skin. To reduce the number of environmental mastitis bacteria, areas where cows lie should be as clean as possible, with no bare ground or heavy manure soiling. Outbreaks of Pseudomonas mastitis have been recorded in situations where cows lie in wet conditions in the first few days immediately after drying-off. These infections may be very severe (often fatal) and are virtually impossible to treat.
- Reducing yields
- One week prior to the final milking date:
- Stop feeding all concentrates.
- Three days prior to the final milking date:
- Move to a paddock with very little feed.
- Reduce feed intake to maintenance level eg. approx. 7-8 kg hay for a cow weighing 500 kg.
- Separate the cows from the main herd if practical.
- Change routine for milking if practical eg. bring the cows to the milking area through a different entry.
- How should you dry cows off?
- Dry-off cows if their production reaches 5 litres or less per day.
Cows producing 10-12 litres per day can be dried off abruptly.Take steps for cows producing more than 12 litres/day, to reduce production to 12 litres or less by the drying-off date.
These steps involve reducing food intake and changing routine.- Decide the date of the final milking for target cows.
- Start preparation for drying-off at least a week before date of final milking. Ideally cows should be dried off abruptly, do not skip days and preferably do not skip milkings. Once a day milking may be necessary in for cows.
- Milk out as usual at each milking until drying-off. Do not deliberately leave some milk in the udder (under milk). It is not necessary to leave milk in the udder at the last milking to improve the action of Dry Cow Treatment.
- At the last milking: Milk out as usual.
- If Dry Cow Treatment is to be used, administer it as recommended by Countdown Downunder.
- Cover whole surface of teat in freshly prepared teat disinfectant (dip is preferable to spray). Don't leave cows in laneways, yards, feed pads or calving pads immediately after drying-off.
- Avoid allowing them to lie down on bare ground or areas that are soiled with manure in the two hours immediately after you give Dry Cow Treatment.
- Put the cows in a dry, clean paddock (not heavily soiled with manure, no bare ground and no exposure to dairy effluent) for 3-4 days after drying-off.
This paddock should be well away from the milking herd and the milking area, so cows don't have the stimulus to let down milk. - 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.
- Check the cows daily for a week. Look for swollen udders and sick cows. Treat all cows that develop mastitis.
- Avoid transporting cows during this period.
This article has been modified from the Countdown Downunder Farm Guidelines.
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