The incubator is set by the book, the eggs are fresh, turning works, and hatchability is 60%. Breaking open the unhatched eggs shows embryos dying on days 10–14, and the chicks that did hatch have short, matted down. The owner blames the machine, but the cause was in the hens’ feeder a month earlier. Everything an embryo grows from, the hen put into the egg from her own feed.
An egg is the embryo’s feed
For 21 days an embryo gets nothing from outside but warmth and air. Vitamins, trace minerals, fat and protein come only from the yolk and white. If a hen is short of something, she may still lay normally, but the embryo won’t have enough. A table egg and a hatching egg need different feed.
What layer feed lacks
Layer feeds are designed for eating eggs. Breeder feeds carry several times more of certain vitamins and trace minerals:
| Nutrient | If it’s short |
|---|---|
| Riboflavin (B₂) | Embryo deaths on days 10–14, chicks with matted “clubbed” down, curled toes |
| Biotin, pantothenic acid | Late embryo deaths, weak chicks, beak deformities |
| Vitamin B₁₂, folic acid | Embryo deaths in the second half of incubation |
| Vitamin D₃ | Thin shells, deaths mid- and late-incubation |
| Vitamin E, selenium | Lower fertility, weak chicks |
| Manganese, zinc | Shortened bones, abnormal leg and beak development |
Vitamins build up in the egg over 2–3 weeks. Switch the flock to breeder feed, or add a breeder premix, at least 3–4 weeks before you start collecting hatching eggs.
The rooster is half the hatch
An infertile egg won’t hatch under any incubator settings. And fertility depends on the rooster as much as on the hen.
- Don’t overfeed. A heavy rooster is lazy and mates less. This goes double for meat breeds and broiler breeders.
- Layer feed isn’t rooster feed. A rooster doesn’t need much calcium, and long-term it can hurt his kidneys. Offer the hens oyster shell in a separate feeder, so the rooster eats a general feed with less calcium.
- Vitamins E and A, zinc and selenium affect semen quality — exactly the ones breeder feeds have more of.
Weight and condition
Broiler breeder flocks must be feed-restricted: they’re fed by the breeder company’s program, or they quickly get fat and almost stop laying. Laying and dual-purpose breeds don’t need strict restriction, but a fat hen lays fewer eggs with good fertility. Weigh ten hens once a month.
Read the unhatched eggs
After each hatch, open the unhatched eggs and note at what stage the embryo died.
| What you see | Possible cause |
|---|---|
| No blood ring, “clear” egg | Infertile: rooster, mating ratio, egg storage |
| Death in the first days | Storage and temperature, less often nutrition |
| Death on days 10–14 | Often riboflavin and other B vitamins |
| Death just before hatch | Incubator humidity and temperature, vitamin D₃ and biotin |
How to set up the incubator is in the incubation settings and mistakes article.
The hatch in your records
In EggPulse incubator batches are logged with the date, number of eggs and hatch. If you note when the flock moved to breeder feed, you can compare the hatch before and after and see whether the pricier feed paid off.
