Cow Gestation Calculator (Calving Date)

Due date from the breeding or AI date for cattle by breed, sheep, goats, pigs, horses and alpacas.

Cow gestation averages about 283 days (roughly 9 months and 10 days), with a normal range of about 279–287 days. It varies by breed: Holsteins and Jerseys calve around day 279, Angus around 281, Herefords around 285 and Brahmans around 292. Bull calves are usually carried 1–2 days longer.

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How to use it

  1. Choose the animal (and breed for cattle).
  2. Enter the breeding or AI date.
  3. Read the expected calving date, the normal window and how far along she is today.

What you enter

What you get

Formula

Due date = breeding date + average gestation length (days) for the species or breed.

The normal window uses the usual range of gestation lengths for that species or breed.

Worked example

Input: Angus cow bred by AI on 1 June

Result: Expected calving 9 March the following year (day 281)

Start watching closely from late February.

Questions

How long is a cow pregnant?

About 283 days on average, a little over nine months. Normal calvings fall between roughly 279 and 287 days, and breed shifts the average by several days.

Is gestation shorter in dairy cattle?

Slightly. Holsteins and Jerseys average about 279 days, while beef breeds such as Hereford, Charolais and Simmental run 285 days or more, and Brahman-influenced cattle about 292 days.

When should I watch for calving?

From about two weeks before the due date. Udder filling, relaxed pelvic ligaments, a swollen vulva and separating from the herd are signs that calving is close.

Limitations

References

More Farm Planning

All free tools · By Dr. Zubair Khalid, DVM, MS, PhD.