Two tools traditionally used to reduce milk volumes before dry-off are reducing the frequency of milking and/or reducing feed intakes.
For cows already producing low volumes of milk, say less than 10L/day, the process is straightforward – just stop milking them. Switching to less frequent milking won't help at this late stage. Instead, focus on reducing feed intakes for the first seven to 10 days after dry-off, then resume feeding to gain condition.
For those cows producing more than 10L/day and being milked twice a day (TAD), advice varies. Both of these common approaches have their upsides and downsides:
- Reducing milking frequency from TAD to once a day (OAD) immediately before dry-off can help reduce milk volumes somewhat, but it can also affect somatic cell counts (SCC) and cause udder swelling/pain.
- Altering nutrition may more effectively reduce cows’ milk volumes (by reducing feed intakes, e.g. metabolisable energy by up to 50 percent). However, this leads to hungry cows and welfare concerns.
What overseas researchers are exploring
The latest research from Europe may provide an alternative approach that better mimics natural weaning by a calf. It explored setting milking machines to remove cups early, once cows reached a predetermined milk volume at each milking.
Thresholds were reduced by five percent each day for the final 10 to 12 days before dry-off. Milk volumes for the trial cows declined from an average of 20kg/day to 14kg/day. Control cows remained on 20kg/day till dry-off. In Europe, the outcomes for udder health and teat condition were good, and slightly better than for cows milked to the conventional take-off point.
This approach is worth investigating in New Zealand systems and exploring how to apply it without relying on sophisticated milking systems. However, it also requires further investigation for higher SCC cows, i.e. those above 100,000 cells/ml.
What we recommend
For now, use a combined approach to reduce milk supply to below 10L/day (less than 0.8kg MS/day), by reducing milking frequency and feed intake in the last seven to 14 days of lactation. Cows can then remain on maintenance levels for a further seven to 10 days, depending on how bagged-up the udders remain.
For more information, see dairynz.co.nz/drying-off
This article was originally published in Inside Dairy April 2020