Key facts
- Average length: 283 days
- Normal range: 279 to 290 days
- Heat cycle: about every 21 days
- Dry-off: about 60 days before the due date
Breed makes a difference: Jerseys tend to calve about 4 days earlier than average, Brown Swiss about 7 days later, and Bos indicus breeds (Brahman, Nelore, Gyr) up to 10–12 days later. First-calf heifers and cows carrying bull calves also tend to run a little long.
For management, mark three dates: the heat check at 21 days (if she comes back into heat, she did not settle), dry-off about 60 days before calving so the udder can regenerate, and the start of close observation one week before the due date.
Signs that calving is near: the udder fills and the teats become tight, the vulva swells and releases clear mucus, the ligaments on either side of the tailhead relax, and the cow isolates herself or becomes restless.
Frequently asked questions
How many months is a cow pregnant?
About 9 months and 10 days (283 days on average). The normal range is 279 to 290 days depending on breed and the individual cow.
How long is gestation in Brahman and other Bos indicus cattle?
Usually longer, around 290 to 295 days, which is 7 to 12 days more than European breeds.
When should I dry off a cow before calving?
Typically about 60 days before the expected calving date, so the mammary gland can regenerate before the next lactation.
How soon can a cow be bred back after calving?
Most producers wait 45 to 60 days after calving (the voluntary waiting period) before rebreeding, aiming for one calf per year.