Even on a good farm, birds sometimes die. An old hen, a weak chick, a random injury: that’s normal life. The real question is how to tell background loss from the start of trouble before it eats half the flock. What helps here is not intuition but a number you write down every day.
How to calculate it
Mortality, % = birds that died ÷ flock at the start of the period × 100
Watch two figures: daily mortality (to catch a sudden jump) and cumulative since the start of the batch or month (to compare against the norm). Count only birds that died. Culls and birds sold are not entered as mortality, or the picture blurs.
What counts as normal
Exact norms depend on the breed or cross, but these work as guidelines:
| Group | Guideline |
|---|---|
| Chicks, first week | up to 1% |
| Broilers, whole cycle (6 weeks) | 3–5% |
| Pullets until laying starts | 3–5% |
| Adult layers | 0.3–1% a month |
If three or four birds out of 1,000 die in a month, there is nothing to worry about. Six in one day is a reason to sit down and investigate.
Warning signs
- Losses rose two- or three-fold over the usual and stay that way for two days running.
- Young birds of one age die, or birds from one section.
- Deaths come with symptoms: rattling breath, diarrhea, swollen heads, bluish combs, a sharp fall in laying.
- Birds die suddenly though they looked healthy. This happens with heat, poisoning and acute infections.
If you suspect a contagious disease, isolate the sick birds, don’t move them between sections and don’t sell them. Call a vet the same day.
What to write down so the vet has an easier job
- Date, age and the section where the bird died.
- How many birds, and which symptoms you saw beforehand.
- What changed in recent days: feed, water, temperature, vaccinations, new birds.
- Feed and water use over the last 24 hours.
- The result of a necropsy, if one was done. Without it, the cause often stays a guess.
Causes to check first
Often it’s not disease but conditions. Check temperature and ventilation, water (not frozen, not run out), feed (a new batch, any mold) and the vaccination schedule. The last is covered in our vaccination article.
Mortality in the app
In EggPulse, mortality is recorded per house, the flock count updates itself, and the percentage and trend show right away. A spike is visible on the day it starts, not at month’s end. The same numbers feed the egg production calculation described in our article on hen-day.
