Cattle Gestation Calculator

Enter the date a cow was bred and this returns the expected calving date, counted forward on the published average gestation of 283 days. Breeds differ, so the gestation length is an input rather than a fixed number: dairy breeds such as Jersey and Holstein average nearer 279 days, Angus around 281, Charolais and Simmental nearer 287, and Brahman influenced cattle can run past 290. Alongside the date you get a window of a week either side and the dates that fall 60 and 30 days before calving. A second tab runs the arithmetic backwards, giving the service date that would produce a calving date you pick. Gestation also varies with the sex of the calf and from cow to cow, so the result is a planning date, not a promise.