UNDERSTANDING CALCIUM SUPPLEMENTATION OPTIONS

THE PROBLEM EVERY FARMER KNOWS: HER FIRST 2 NIGHTS

You know the routine. Your cow calves overnight or early morning. You collect her after the morning milking around 9AM, remove the calf, milk her, give her a bolus, and she goes into the colostrum mob. Job done. You head off to do the rest of the day's work.

But here's what's happening while you're not there - have a look at the graphic above, particularly those two blue shaded zones marked "Night 1" and "Night 2" (10PM-7AM).

The Real Timing Problem:

Most calcium boluses give you about 8-12 hours of protection. So if you dose her at say 9AM:

  • By later that evening, that calcium boost is wearing off

  • That first night (10PM-7AM) she's well below safe levels while you're asleep

  • Then she’s into the second night (10PM-7AM) with no extra support coming in.

  • And that second night? That's sitting smack in the middle of when 67% of milk fever cases actually happen

What the lines tell you:

  • Red line (1 bolus at 9AM): Watch what happens through both nights. Night 1 she's already dropping below the safe threshold. Night 2 (the darker red "PEAK RISK" zone) she's got nothing left and that's exactly when most cows go down. This is why you find down cows on that second or third morning.

  • Orange line (2 boluses): Even with a second dose at evening milking, the protection runs out well before that critical second night when 67% of cases occur.

  • Teal line (Cow Start Complete at 9AM): Stays well above the safe level through both Night 1 AND Night 2. One dose at morning milking on Wednesday keeps her protected through to Friday morning and beyond.

Why This Second Night Matters So Much:

The research is crystal clear: 31% of cases in the first 24 hours, but 67% on day two. Count it out from a 9AM bolus:

  • Day 1: Wednesday 9AM to Thursday 9AM (31% of cases)

  • Day 2: Thursday 9AM to Friday 9AM (67% of cases - Night 2 is right in the middle of this)

That second night is when you're most likely to have them go down so you need your calcium supplementation to still be working.

NOW LET’S TALK ABOUT YOUR FARM

The research is one thing. Not finding down cows on that second or third morning is another. That's what the calculator below is for.

Every down cow costs you time, money, and stress. Some don't get back up. The calculator helps you work out what that's actually costing your operation versus investing in protection that actually lasts through both critical nights. It also works out the hidden cost that subclinical hypocalcaemia is robbing from you.

Put in your numbers:

  • How many cows you're calving

  • What you're getting for milk

  • What you're currently spending on calcium supplements

Have a play with the numbers and see if there's a better way to get your at risk cows through those first 2 nights. Our presets are all based upon available published research regarding various calcium boluses/ supplementation strategies and Dairy NZ research around the costs of milk fever and subclinical hypocalcaemia (scaled to 2025 payout). However if you disagree with our numbers - simply change them!