DCAB: Stop Being Afraid of It!

The transition period is the twenty-one days either side of calving. Get it right and the rest of the lactation follows. Get it wrong and you could spend the next ten months firefighting. To kick off Year Five, we're joined by Vicky Ham, Ruminant Technical Services Manager, Europe for Arm & Hammer Animal Nutrition, to talk about DCAB — what it actually is, why it still strikes fear into people who should know better, and why the research keeps pointing in the same direction. The work goes back to Dr Elliot Block in the mid-1980s and is reinforced by meta-analyses from J.E.P. Santos: cows fed a negative DCAB diet calve with better calcium status, suffer fewer transition diseases, and eat more dry matter post-calving. The evidence is there. The question is why more people aren't using it.

We cover the basics of acidification and how urine pH testing tells you whether cows are actually where they need to be — and why there is no such thing as a partial DCAB diet. You are either acidified or you are not. On the practical side we talk forage mineral analysis, straw potassium surprises in drought years, protein source selection, palatability, mixing, and why consistency is everything. We also cover what happens post-calving, stocking density, feed space, and why cows need to come off the negative DCAB ration the moment they calve.

We also get into newer thinking on inflammation — the emerging evidence that hypocalcaemia may be less about calcium deficiency and more about an activated immune system demanding calcium and glucose at the expense of everything else. Studies suggest close to sixty per cent of cows at calving show inflammation with no clinical signs whatsoever. Managing that inflammatory load is not a separate conversation from transition nutrition. It is the same conversation. 

This episode was recorded in June 2026, and all information was correct at the time of recording.  Please note this transcript was generated using AI transcription software — despite best efforts to ensure accuracy, there may be some errors in the final piece. 

Are you running a DCAB diet, and if not, what's holding you back? We'd love to hear from you. Please share, subscribe, and leave us a review — it helps more dairy farmers find us.

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