Lambing percentage: find where you lose lambs
Demand for lamb is running ahead of what Prairie flocks can supply, and the gap is not closing quickly. The national breeding flock grew about 2.2% over the past year, and market lamb numbers rose 5.1% — real growth, but slow against the demand sitting in front of it.
There are only three ways to put more lambs on the truck: keep more ewes, lose fewer lambs, or get more lambs weaned per ewe you already feed. Buying ewes is slow and expensive. The other two — your lambing percentage and your death loss — are the levers you actually control this year. And both of them are records problems before they are anything else.
What lambing percentage actually counts
"Lambing percentage" gets used loosely, which is part of the problem. Three different numbers hide under the same phrase, and the distance between them is where the money leaks:
| Number | What it measures | Where it's set |
|---|---|---|
| Scanning % | Fetuses per ewe exposed | Breeding and ewe condition |
| Lambs born % | Lambs born per ewe lambed | Lambing |
| Lambs weaned % | Lambs weaned per ewe exposed | Birth through weaning |
The number that pays your bills is the last one — lambs weaned per ewe exposed. A flock can scan at 175% and still wean 135%. That 40-point gap is not bad luck; it is a measurable loss happening at a specific point you can find.
The gap is bigger than it feels
Take a 200-ewe flock that scans 175% but weans 135%. On paper that is "a good year." In lambs, the gap is 40 points across 200 ewes — about 80 lambs that were carried but never weaned. At any realistic lamb value, that is a serious number walking off the place, and in a market that wants every lamb you can raise, it is the lowest-cost flock expansion available: you already fed those ewes.
The flock that knows where those 80 lambs went can do something about it next year. The flock running on memory and a feed-store calendar cannot, because by August nobody remembers which ewes slipped, which ones mismothered, or whether the losses were at birth or in the first three days.
What to record to find the leak
You do not need a research trial. You need four touch points written down against the ewe's ID, on paper, a spreadsheet, or an app — whatever survives the barn.
- Breeding: ewe ID, ram or breeding group, turn-in and turn-out dates. This sets the due dates and lets you tie a poor outcome back to a specific ewe and sire.
- Scanning: open, single, twin, triplet. Opens and repeat singles are your first cull signal.
- Lambing: for each ewe — lambs born alive, born dead, assisted or unassisted, and any mismothering or rejection. Note the date and the lamb IDs.
- Weaning: lambs weaned per ewe. Compared against scanning, this closes the loop.
That is enough to calculate all three percentages and, more importantly, to see which ewes and which stage are costing you.
Death loss has a time and a cause
"We lost some lambs" is not a record. "Lost 11 lambs, 8 of them in the first 48 hours, 5 of those to mismothering on first-time ewes" is a record — and it points straight at a decision.
Lamb death loss clusters. It clusters in the first days after birth, it clusters in certain ewes, and it clusters around a handful of causes: chilling, starvation and mismothering, scours, predation. When you write down the age at death, the likely cause, and the ewe's ID every time, the pattern shows up by the end of the season instead of staying a vague feeling that this year was rough.
That pattern is the difference between guessing and acting. If most of your loss is mismothering on first-time ewes, the fix is management — jugging, supervision, drafting ewe lambs into a closer-watched group. If it is concentrated in a few older ewes that fail every year, the fix is a cull list. If it is scours in week two, that is a conversation with your vet, grounded in dates and numbers instead of a hunch.
From records to decisions
Records do not raise your lambing percentage on their own — they show you where it is being lost, so you and your vet can decide what to change. Three decisions tend to fall out of one season of honest numbers:
- The cull list builds itself. The ewes that came up open, weaned a single off a twin, or mismothered two years running are on the list before you walk to the chute — by reason, not by who looks rough in the alley.
- Replacements get chosen on performance. Keeping ewe lambs out of your high-twinning, easy-lambing ewes tends to do more for next year's percentage than any input you can buy.
- You know where to spend. If the leak is at lambing, supervision and barn space pay back. If it is health, the vet visit is targeted. You stop spreading effort evenly across a problem that is concentrated in one place.
In a year when the market wants every lamb, the flock that can name where its lambs went has an advantage over the one that cannot — and it costs nothing but the discipline to write four things down per ewe.
Ranch.Bot turns plain-language notes like "ewe 412 twins, lost one to mismothering" into structured records you can sort by ewe, by reason, and by season — and you review every record before it saves. It is built and tested on a 200-ewe commercial operation in Northern Alberta. Start a 14-day free trial at ranch.bot.