Abrupt or gradual cessation of milking at dry off; which method is best?
By Dr Peter Younis
For many years the recommendation from Countdown has been that abrupt cessation of milking should be practiced for cows giving less than 12 litres per day. For cows producing more than this, it is desirable to reduce production before drying off.
Abrupt Dry Off: Cows are milked at their normal frequency (In Australia usually twice daily) right up to their last milking.
Gradual Dry Off: Some milkings are missed in the period before drying off. Typically, cows will be milked once daily.
What is the science behind this and should we review our recommendations?
The dry period is necessary for the udder to repair itself and prepare for the next lactation. It is also an opportunity for us to use long acting antibiotic dry cow therapy (DCT) to remove existing intra-mammary infections (IMI’s) without having to discard milk or risk an antibiotic residue.
The dry period is also a period of increased risk for the cow to acquire new IMI’s.
We know that many, at least 50%, of the cases of clinical mastitis that occur in the first 100 days of lactation have been acquired during the dry period. We can reduce this risk considerably by using a teat sealant with or without an antibiotic immediately after the last milking.
Many studies have also shown that the method of drying off has an impact on the rate of new infections acquired during the dry period and the rate of mastitis in early lactation. Some of the findings include
Gradual cessation of milking reduced production and resulted in fewer IMI’s during the dry period
Gradual or abrupt cessation of milking resulted in similar IMI’s if DCT was used.
Every 5 litres increase in milk yield above 12.5 litres resulted in a 77% increased risk of an IMI at calving
Milk leakage during various stages of lactation resulted in an increased risk of clinical mastitis
Milk leakage during the first week of the dry period resulted in a 4 times increased risk of mastitis later in the dry period
Cows producing greater volumes of milk at dry off had higher ICCC’s in the following lactation.
Cows dried off using gradual cessation had significantly less milk leakage than abruptly dried off cows. (75 v 27%).
Reducing the plane of nutrition resulted in a 30% reduction in milk yield and had a greater effect than once daily milking alone.
Halving dry matter intake resulted in a greater drop in production and fewer leaking cows than once daily milking. However, cows with both reduced DMI and once daily milking had the lowest production level at dry off.
Gradual dry off, by milking once daily for 7 days, reduced milk yield from 19.8 to 13.2 litres as compared to abrupt dry off where cows had dropped to only 18.9 litres over the 7 days
These results are only a few of the many studies done around the world in variable production systems so how should we interpret them for our purposes?
The information above is of a general nature and we are very happy to discuss individual farm options at any time.
It is very likely that reducing milk yield in cows prior to drying off will result in reduced risk of IMI’s during the dry period as well as reduced ICCC’s and clinical mastitis rates in early lactation.
We can do this by;
- reducing feed intake to maintenance levels for at least 1 week prior to dry off
- milk once daily for a few days prior to dry off. Five to seven days is a current suggestion.
- We are currently not recommending skipping a full day between milkings.
- Change the cow’s routine so she is away from the sights and sounds of the dairy. This will lessen the likelihood of milk leakage.