📋 Before you start
Set this up before you record any treatments.
This is the smallest section in the app and the one with the best return on ten minutes of setup. You enter each product once, with the withholding periods printed on its label. From then on, selecting that product when you record a treatment fills the withholding dates in automatically.
⚠️ Why this matters more than it looks
Withholding mistakes are the ones with real consequences — meat or milk entering the food chain inside a stand-down period. They almost never happen through carelessness. They happen because someone was reading small print on the back of a bottle in poor light while holding a drench gun, six weeks before it mattered. Reading the label once, at the kitchen table, is a materially safer system.
Products & Chemicals is off by default for new accounts — find it in Settings → What do you track? if it isn't showing.
1️⃣ Adding a product
Bottle in one hand, phone in the other.
Use + Product. The fields:
- Product name — as it appears on the label, so you recognise it in a list in two years.
- Category — Drench, Lice treatment, Vaccine, Wormer, Fly strike treatment, Weed spray, Fertiliser, Disinfectant or Other.
- Supplier / brand.
- Active ingredients — worth filling in. See below.
- Notes.
Withholding periods, from the label
Then the part this exists for — five fields, each taken straight off the bottle:
- Meat (ESI) days
- Milk days
- Egg days
- Wool days
- Grazing / paddock days — for sprays and fertiliser, and what drives the "do not graze until" warning when you try to move stock in.
- Other withholding — a label and a number, for anything that doesn't fit the above.
Leave any that don't apply blank.
2️⃣ Using it
Where the setup pays off.
When you record a treatment — on an animal, through a job, or on a herd — there's a product picker at the top of the form. Choose the product and the withholding fields populate from your register.
You can still type amounts manually if you're using something that isn't in the register. The picker is a shortcut, not a gate.
⏰ Add the time as well as the date
Withholding is calculated to the hour when the treatment carries a time. Without one you get a whole-day estimate — safe, but it can cost you the best part of a day at the far end.
3️⃣ Active ingredients and resistance
Why that optional field is worth filling in.
Two different-looking drenches can share an active family. Rotating between them isn't rotating at all — and using the same active repeatedly is how drench resistance builds on a block, which is one of the more serious problems facing NZ small farms.
Recording the active ingredients means your treatment history shows what an animal has actually had, not just which bottles you bought. Combine that with the drench follow-up reminder — which appears about twelve days after a drench, prompting a condition check or faecal egg count — and you start getting a real answer to whether your drench is still working.
See the Animals guide for condition checks and FEC recording.
✅ What the app does vs what you do
The honest split.
My Block Hand handles: a register of products with categories, suppliers and active ingredients; stored withholding periods for meat, milk, eggs, wool, grazing and a custom category; auto-filling those into any treatment you record; calculating cut-off dates to the hour; and warning you when a move or a production record falls inside a stand-down.
You still have to: read the label and enter it correctly — everything downstream depends on those numbers being right; check whether the label has changed when you buy a new batch; and follow your vet's advice on what to use and when.
This guide describes My Block Hand as at July 2026. The app calculates withholding from the figures you enter — it holds no product database and cannot check them. Always use the current label for the product in your hand, and talk to your vet about treatment choices. For more on drench resistance, Beef + Lamb NZ's Wormwise programme is the NZ reference.