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.
1 Incubation lasts 12-13 days. 2  It usually begins the day before the female lays the last egg, so that all eggs will hatch within 24 hours of each other. 3  If eggs are laid late in the season, incubation may start earlier. If eggs are laid late in the season, incubation may start earlier. 2  Incubation usually occurs for 20-25 minute time periods, interrupted by 7-8 minutes for feeding. 3  Apparently only the female incubates. 4  Hatching: for the first few days, the male brings almost all the food so the female can keep hatchlings warm.