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.
Hatching can take place over several days. For chickens, run the incubator for 24 days (3 days more than normal hatch time). For ducks and turkeys run the incubator for 32 days (4 days more than normal hatch time).atching can take place over several days. For chickens, run the incubator for 24 days (3 days more than normal hatch time). For ducks and turkeys run the incubator for 32 days (4 days more than normal hatch time).