Ostrich Chicks, Breeding Density and Finishing

#Seventy-eight per cent, and what it does not mean

In one season at one intensive rearing unit, researchers followed 2 522 artificially incubated ostrich chicks. By 90 days, 78.4% of them were dead — 46.7% before 28 days and another 30.7% between 28 and 90 days (Cloete et al. 2001).

That is one severe season in one system, not the industry norm, and you should not carry it around as one. The only sourced working benchmark is the Western Cape department's: chick mortality "could be up to 30% with many variations between farmers and seasons" (WCDoA 2020). Take 30% as the benchmark, 78% as the documented worst case, and resist averaging them into something comfortable.

What makes the study valuable is not the headline. It is the three predictors of survival it identified, all of which you can measure with a scale and write in a book — before the losses happen, while doing something about them is still cheap.

#Three levers, one scale

Lever one: egg water loss to day 35. Weigh every egg when it goes into the incubator and weigh it again at day 35. Cumulative water loss above about 18% flags that chick as high-risk before it has hatched.

The response is the part farmers get wrong. High water loss is a message about the incubator's humidity and the egg's environment, not about the chick. You change the machine, not the bird.

Lever two: day-old mass. Weigh every chick at hatch. Below about 762.5 g is a flagged bird — separate management, not the general pen where it will be out-competed at the feeder. The industry average day-old mass is around 750 g (WCDoA 2020) — the threshold sits above the average, so expect to flag a fair share of a normal hatch, not a rare exception.

Lever three: 28-day mass. This is the one worth writing on the shed wall. In the Cloete data, chicks averaging 1 050 g at 28 days went on to exceed 80% mortality. Chicks at 1 950 g or more came in at 20–30%.

#Before the chick exists: eggs and incubation

Almost the whole industry incubates artificially, and every link in the chain from nest to hatcher is measurable. Collect daily and often — an egg left in a Klein Karoo afternoon or a Highveld thunderstorm is the first loss of the season. Clean, disinfect and store cool before setting. Set in batches against a control.

The national flow model gives the yardstick: about 25 000 breeder birds producing roughly 500 000 eggs and about 325 000 chicks, at a standard 65% hatchability and a day-old mass of about 750 g (WCDoA 2020). If your hatchability sits well below 65%, the fault is almost always upstream of the hatcher — breeder nutrition, breeder age, camp density, egg handling, storage. Chasing it inside the machine is chasing the wrong end. Budget the infertile eggs in rather than writing them off: they have a genuine second market in the baking trade, and the shells go to the craft trade.

One honest gap: there is no single authoritative South African table of incubation temperature, humidity, turning frequency and storage duration. Those set-points are machine- and altitude-specific. Get them from your incubator manufacturer and the Oudtshoorn Research Farm, then correct them against your own water-loss records.

#The density result that runs the wrong way

This is where the South African research gets uncomfortable.

At Oudtshoorn, Lambrechts and colleagues ran breeding flocks in one-hectare camps at 114, 130 and 141 birds per hectare (SAJAS 34(2), 2004). Per-bird fertility and hatchability both declined as density rose — fertility by about 0.062 ± 0.020 percentage points per additional bird, hatchability by about 0.106 ± 0.028 points per bird in the 2000/01 season. So far, so predictable.

But total egg output per camp rose with density. Of the three densities tested, 114 birds per hectare was the best on a per-bird basis; it was not shown to be an optimum, and no lower density was tested.

The small-camp results point the same way. Nine birds in a 0.13 ha camp produced 23.5 more chicks than nine birds in a 0.30 ha camp. Same nine birds, less than half the space, more chicks. Trios gave 68% higher egg production per female than nine-bird flocks. In quads, each additional female added 29.1 ± 2.3 eggs per camp, and raising the male-to-female ratio from 1:1 through 1:2 to 1:3 did not compromise fertility.

The authors' own conclusion is the sentence to carry out of the paper: breeding ostriches "could be maintained at stocking rates higher than what is currently recommended for intensive commercial ostrich breeding enterprises."

For budgeting, use 30 eggs per hen per year — the South African industry average (WCDoA 2020). International reviews collate 40–60 eggs in a mature season (Akram et al. 2025), but none of those figures are South African. Treat anything above 30 as an achievement to be proven on your own records.

#Finishing: two feed rules that do not mean the same thing

Ostriches are slaughtered young. Under research conditions at Oudtshoorn, birds went at 337 days at a live weight of 83.4–93.6 kg (Brand et al. 2020). Average daily gain ran 0.35–0.43 kg on starter, 0.41 kg on grower and dropped to 0.29 kg on finisher — growth slows as the bird nears slaughter weight, which is why holding birds longer is expensive rather than free. Feed conversion came in between 4.05 and 5.38, on dry matter intakes of 1.34, 1.89 and 2.65 kg per bird per day across the three phases, averaging about 2.02 kg.

DALRRD's rule of thumb for the same job is 10–14 months to slaughter and 2.5 kg of feed per bird per day (DALRRD 2023).

Both are correct. They are not the same measurement, and putting them in one spreadsheet is how feed budgets go wrong.

#Work it for 100 birds

You are budgeting feed for a batch of 100 slaughter birds to 337 days.

Using DALRRD's rule of thumb: 2.5 kg × 337 days × 100 birds = 84 250 kg, or 84.25 t as fed. That is the number to price against a pellet quote, because pellet quotes are per tonne as delivered.

Using Brand's dry matter intakes: 2.02 kg DM × 337 days × 100 birds = 68 074 kg, or 68.1 t of dry matter. That is the number to use in any nutritional calculation — protein supply, energy density, feed conversion.

The gap is about 16 t. It is not a disagreement about ostriches — it is water. You cannot close it without the dry matter percentage of your own feed, which is on your feed analysis and not in any course. Decide which basis your budget is on, write it at the top of the sheet, and never mix the two.

#Worms: monitor, then decide

Two internal parasites matter enough to name.

Libyostrongylus douglassii, the ostrich wireworm, lives in the crypts of the glandular stomach — the proventriculus — and is regarded internationally as the most economically important gastrointestinal parasite of the species. Diagnosis is by faecal examination (Merck Veterinary Manual). It is a classic dirty-camp, wet-ground, high-density parasite, and the levers are ones you already own: camp rotation and rest, dry lying areas, and not concentrating young birds on ground that has carried ostriches continuously.

Houttuynia struthionis, the ostrich tapeworm, is described as common in Africa. Its intermediate host is unknown, which limits any control strategy to hygiene and monitoring.

Note what this section does not contain.

The decision rule is not a product: monitor by faecal egg count and post-mortem, and treat on evidence rather than on the calendar. Current prevalence of either parasite on South African commercial units is not published, so manage by measurement rather than assumption.

Weigh the eggs. Weigh the chicks at hatch and at 28 days. Count the eggs before you treat. Every one of those is a decision made from a number you generated yourself, on a farm where almost every other number you will be quoted is somebody else's.