Cattle
| Kind | Days | Months | Spread, days |
|---|---|---|---|
| Angus | 279 | 9.2 | 274–2832 in 3 |
| Red Angus | 282 | 9.3 | 277–2872 in 3, our estimate |
| Hereford | 284 | 9.3 | 279–2892 in 3, our estimate |
| Charolais | 283 | 9.3 | 278–2882 in 3, our estimate |
| Simmental | 285 | 9.4 | 280–2902 in 3, our estimate |
| Gelbvieh | 284 | 9.3 | 279–2892 in 3, our estimate |
| Limousin | 286 | 9.4 | 281–2912 in 3, our estimate |
| Brahman | 292 | 9.6 | 287–2962 in 3, our estimate |
| Holstein | 280 | 9.2 | 275–2842 in 3, our estimate |
| Jersey | 280 | 9.2 | 275–2852 in 3, our estimate |
| Ayrshire | 282 | 9.3 | 277–2862 in 3, our estimate |
| Guernsey | 286 | 9.4 | 281–2902 in 3, our estimate |
| Brown Swiss | 288 | 9.4 | 283–2922 in 3, our estimate |
| Other or not sure | 283 | 9.3 | 278–2882 in 3, our estimate |
If she does not settle, she comes back into heat about every 21 days. Find the due date for your cow.
Horses and donkeys
| Kind | Days | Months | Spread, days |
|---|---|---|---|
| Horse | 338 | 11.1 | 320–370normal range |
| Donkey | 371 | 12.2 | 354–3872 in 3 |
If she does not settle, she comes back into heat about every 21 days. Find the due date for your mare.
Goats
| Kind | Days | Months | Spread, days |
|---|---|---|---|
| Standard goat | 150 | 4.9 | 144–155normal range |
| Nigerian Dwarf | 149 | 4.9 | 145–153normal range |
If she does not settle, she comes back into heat about every 21 days. Find the due date for your doe.
Sheep
| Animal | Days | Months | Spread, days |
|---|---|---|---|
| Sheep | 147 | 4.8 | 144–152normal range |
If she does not settle, she comes back into heat about every 17 days. Find the due date for your ewe.
Pigs
| Animal | Days | Months | Spread, days |
|---|---|---|---|
| Pig | 114 | 3.7 | – |
If she does not settle, she comes back into heat about every 21 days. Find the due date for your sow.
Rabbits
| Animal | Days | Months | Spread, days |
|---|---|---|---|
| Rabbit | 30 | 1.0 | 28–33normal range |
Alpacas and llamas
| Kind | Days | Months | Spread, days |
|---|---|---|---|
| Alpaca | 346 | 11.4 | 339–3531 in 2 |
| Llama | 349 | 11.4 | 342–355normal range |
How to read this chart
Days is the average days from breeding to birth. Months is the same, in months.
Spread is when most births come. "2 in 3" means about 2 of every 3 births fall in those days. "Normal range" is the range the source calls normal.
Some cattle spreads are our estimate. We borrow the spread from Angus, where the source gives only an average.
For birds, see the egg incubation calculator.
Questions
How long is a cow pregnant?
About 9 months. It depends on the breed: about 279 days for Angus, 284 for Hereford and 291.5 for Brahman. Many books say 283.
How long is a horse pregnant?
About 335 to 340 days, or 11 months. Anything from 320 to 370 days is normal.
Which farm animal is pregnant the longest?
Of the animals here, the donkey: about 371 days, a little over a year.
Which is pregnant the shortest?
The rabbit: about 30 days.
How long are goats and sheep pregnant?
About 5 months. Goats about 150 days, sheep about 147.
Sources
- K-State Beef Tips, When Is She Due?Jul 2026Angus gestation from 101,787 AI matings, and its spread; the 283-day textbook figure
- Virginia Cooperative Extension, Beef Breed Differences (U.S. Meat Animal Research Center data)undated, data 2001Gestation by breed of the bull
- Moore et al., Animal Production Science (Australian herds)Dec 2025Brahman gestation
- Hoard’s Dairyman, Why all gestations aren’t equal (USDA-ARS copy)2008Gestation by dairy breed, first and later calvings
- Nebraska Extension G1874, The Foaling MareJul 2008Mare gestation 335 to 340 days on average, 320 to 370 normal
- Theriogenology, gestation in jennies (PubMed)Mar 2019Donkey gestation, 28 jennies
- Tennessee State University and UT Extension, Reproduction Management for Healthy GoatsundatedGoat gestation 150 days (144 to 155)
- Miniature Goat Breeders Association, Nigerian DwarfundatedNigerian Dwarf gestation 145 to 153 days
- New Mexico State University, Reproduction in SheepundatedEwe gestation 147 days (144 to 152); heat every 17 days
- Purdue Animal Sciences, sow reproductionundatedSow gestation 114 days; heat every 21 days
- Utah State University Extension, Basic Rabbit Selection and BreedingJul 2025Rabbit gestation 30 days (28 to 33); no heat cycle
- Ponthier et al., Reproduction in Domestic Animals: Pregnancy Length in Alpaca2025Alpaca gestation from 7,049 pregnancies: 346 days, half within 339 to 353
- UC San Diego, Comparative Placentation: CamelidaeApr 2008Llama gestation 342 to 355 days