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Ratites 77

Figure­4.1­ Depressed young ostrich separating
from other chicks.

available. Careful record keeping and frequent assessment of incubation parameters and growth of
chicks is essential to maximize production and for early identification of management errors and
impending health problems.

­ Record­Keeping

Commercial ratite farms keep extensive records on breeding, egg laying, incubation parameters,
egg weight loss during incubation, hatch times, and chick growth and development.

­ Incubation­of Eggs

Ratites are seasonal breeders, with egg production linked to increasing daylight in ostrich, rhea,
and kiwi; decreasing daylight in emu; and availability of food sources in cassowary (Folch 1992a–e;
Biggs 2013). Eggs are laid in depressions in the ground; hence, environmental cleanliness is impor-
tant to reduce egg contamination and maximize hatching success. They should be collected and
given a specific identity as soon as possible after lay. Eggs are often stored after collection to syn-
chronize incubation of groups of eggs. Hatchability generally decreases with increased storage
time, i.e. after 7–10 days for ostrich eggs. Ostrich eggs are stored at 50–68 °F (10–20 °C) with twice‐
daily turning during this period. Emu eggs are stored at temperatures of 40–60 °F (4.5–15.5 °C) and
may be more tolerant of longer storage periods (Minaar 1998). Hatching rates of ratite eggs,
especially ostrich, are considerably less than those for commercial poultry.