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.
Time Frame. You can incubate and hatch duck eggs yourself or you can allow a broody duck (or even a broody hen) to lay on them to incubate and hatch the eggs. Mallard duck eggs hatch after about 27 days of incubation.Muscovy duck eggs take 35 days to hatch.Pekin duck eggs and most other duck eggs hatch after 28 days of incubation.If the eggs are old or if the incubator is not warm enough, incubation may take longer. If the incubator is too warm, incubation happens more quickly. However, several hours of too high or too low of a temperature can be dangerous for the egg.ime Frame. You can incubate and hatch duck eggs yourself or you can allow a broody duck (or even a broody hen) to lay on them to incubate and hatch the eggs. Mallard duck eggs hatch after about 27 days of incubation.