Bovine Gestation Period
The bovine gestation period depends on which bovine you mean. The word covers every animal in the cattle family: European and zebu cattle, water buffalo, bison and yak. They’re close relatives, but their pregnancies aren’t the same length. A swamp buffalo carries her calf almost two months longer than a yak does.
Below is the bovine gestation period for each one, followed by three tools that go further: a calculator, a fetal development chart and a printable table.
Bovine gestation length at a glance
| Bovine species / type | Average gestation | Usual range (days) | Months | Bred Apr 1 → due |
|---|---|---|---|---|
| Domestic cattle, European typeBos taurus | 283 days | 279–287 | 9.3 | Jan 9 |
| Dairy cattle (Holstein, Jersey)Bos taurus | 279 days | 274–284 | 9.2 | Jan 5 |
| Zebu cattle (Brahman)Bos indicus | 292 days | 285–298 | 9.6 | Jan 18 |
| American bisonBison bison | 279 days | 270–293 | 9.2 | Jan 5 |
| YakBos grunniens | 262 days | 257–270 | 8.6 | Dec 19 |
| Water buffalo, river type (Murrah)Bubalus bubalis | 310 days | 305–315 | 10.2 | Feb 5 |
| Water buffalo, swamp typeBubalus bubalis | 330 days | 320–340 | 10.8 | Feb 25 |
For domestic cattle, the textbook number is 283 days, or about 9 months and 10 days. Breed moves it around more than most people expect. Holsteins average about 279 days, while Brahman cows often go past 290. If you are working with cattle, the cattle gestation calculator has all 21 breeds.
Bovine gestation tools
Why bovine species differ
Body size explains part of it, but not all. Water buffalo are big, slow-maturing animals with a long pregnancy. Yak live at high altitude with a short summer, and calves have to be born early enough in the year to grow before winter. Bison sit close to cattle, although wild herds calve over a fairly tight spring window.
Within one species, the same factors apply as in cattle. Male calves are usually carried a couple of days longer, twins come early, and the sire’s genetics shift the date. Nutrition matters too. Bison researchers in Nebraska note that gestation length depends on feed supply and the cow’s condition.
Bovine gestation in months
- Cattle: a little over 9 months (about 9.3)
- Zebu cattle: about 9.6 months
- Bison: roughly 9 to 9½ months
- Yak: about 8½ months
- Water buffalo: 10 to 11 months, depending on type
Bovine gestation FAQ
What is the bovine gestation period?
For domestic cattle it is about 283 days. Across the whole bovine family it runs from around 260 days in yak to about 330 days in swamp-type water buffalo.
How long is a water buffalo pregnant?
River buffalo such as the Murrah average roughly 305 to 315 days. Swamp buffalo are longer, often 320 to 340 days.
How long is a bison pregnant?
Usually 270 to 293 days, with most calves born around day 275 to 280. You will often see 285 days quoted as a round figure.
How long is a yak pregnant?
About 257 to 270 days, which is shorter than domestic cattle.