This is similar to the pregnancy period of a woman, which is closer to around 9 months or ~260 days. However, actual gestation period of a cow can range from 270 days to 295 days, depending primarily on breed[s], age, body condition and nutritional health.Gestation period is also controlled by genetics, but not rate of maturity.his is similar to the pregnancy period of a woman,  which is closer to around 9 months o â¦ r ~260 days.    However, actual gestation period of a cow can range from 270 days  to 295 days, depending primarily on breed[s], age, body condition  and nutritional health.
Whereas fertilized chicken eggs usually take exactly 21 days to hatch, most duck eggs take 28 days, apart from Muscovy ducks. As a general rule of thumb, the eggs of Muscovy ducks take 35 days, but once again, it can vary slightly depending on conditions.
Incubation Period of Other Species. One of the miracles of nature is the transformation of the egg into the chick. In a brief three weeks of incubation, a fully developed chick grows from a single cell and emerges from a seemingly lifeless egg. Not every avian eggs hatch in 21 days.See the chart below for incubation periods for other fowl.The duckbill platypus is the only mammal that lays eggs and they have an incubation period of 12 days. Never incubate the eggs of wild birds; these chicks will not live without their mother's care if they do hatch.Incubation Periods (species and days required to hatch).n a brief three weeks of incubation, a fully developed chick grows from a single cell and emerges from a seemingly lifeless egg. Not every avian eggs hatch in 21 days. See the chart below for incubation periods for other fowl.