Why farmers should do the calculations before drying off cows

Dairy farmers are beginning to focus on drying off their cows in advance of the winter, but at what point should you actually stop milking?

According to UCD’s Dr Finbar Mulligan, drying off cows early (12 weeks before calving) is not the only option available to farmers who have under-conditioned cows.

The Lecturer at the UCD School of Veterinary Medicine advised farmers to look at the economics and the potential income that could be generated before drying cows off early.

“I sometimes wonder is it completely appropriate to dry off cows early as it is not the only option available to farmers.

“Drying off early can be very touch and go and some farmers view milking on as an option when profitability or cash flow is an issue,” he said.

Under Irish conditions, he said, farmers may be able to milk cows on provided they introduce concentrates into the diet.

One element farmers need to examine is what level of yield will be lost by drying cows off early.

Mulligan said that in some cases the introduction of 100kg of concentrates or cereals in late lactation may provide a return on investment in the final weeks leading up to drying off.

The introduction of concentrates in late lactation, he said, and the extra days of milk may allow farmers to produce more income in the weeks leading up to drying off.


Further, he said the additional concentrates fed during the final weeks of lactation will allow cows to build up condition in the weeks leading up to drying off.

The value of the milk solids produced and the cost of the additional concentrates must be calculated to ensure that such a practice makes economic sense, he said.

However, Mulligan also said that farmers don’t want very short dry periods, as this could potentially lead to problems with antibiotic residues in milk in early lactation.

Have a good look at your cows at drying off

Mulligan also advised farmers to pay careful attention to the Body Condition Score (BCS) of their cows at drying off.

Farmers need to identify thin, ideal and over-conditioned cows at dry off, he said, as these cows will require differing degrees of management over the winter months.

Under-conditioned cows (BCS of 2.5-2.75) need to receive preferential treatment over the winter months to ensure that these cows are in the correct condition score at calving.

Furthermore, he added that excessively fat cows will need to be given restricted access to grass silage over the winter months to ensure that these cows do not become excessively fat at the point of calving.

But, no cows should be restricted during the final two weeks prior to calving, he said.

In an ideal scenario, he said that 90% of cows should have a BCS of 3 at drying off, but generally speaking this figure is closer to 70% at farm level.

Source: Finbar Mulligan UCD