How to Use the Livestock Gestation Calculator
Select the species you’re breeding from the dropdown — the typical gestation length fills in automatically. You can adjust the number of days if needed. Enter the breeding or exposure date, then click Calculate to get the estimated due date.
Livestock Gestation Periods
| Species | Average Gestation (Days) | Estrous Cycle | Estrus Duration |
|---|---|---|---|
| Cattle | 283 (about 9 months) | 18–24 days (avg. 21 days) | 12–18 hours (avg. 15 hours) |
| Horse | 340 (about 11 months) | 19–25 days (avg. 21 days) | 4–7 days |
| Donkey | 365 (about 12 months) | 21–28 days (avg. 24 days) | 5–7 days |
| Mule | 365 (about 12 months) | Usually sterile (estrous cycle uncommon) | Not applicable |
| Zebra | 375 (about 12–13 months) | 22–28 days | 5–7 days |
| Llama | 350 | Induced ovulator (no regular estrous cycle) | Receptive for several days if not ovulated |
| Alpaca | 345 | Induced ovulator (no regular estrous cycle) | Receptive for several days if not ovulated |
| Goat | 150 (about 5 months) | 18–22 days (avg. 21 days) | 24–48 hours |
| Sheep | 150 (about 5 months) | 14–19 days (avg. 17 days) | 24–36 hours |
| Pig | 114 (about 3 months, 3 weeks, 3 days) | 18–24 days (avg. 21 days) | 2–3 days (48–72 hours) |
| Rabbit | 31 | Induced ovulator (no regular estrous cycle) | Receptive most of the time (about 12–14 days) |
| Cat | 63 | 14–21 days (seasonal, if not mated) | 4–10 days (avg. 7 days) |
| Dog | 63 | 5–8 months (avg. 7 months) | 7–10 days (standing estrus) |
Why Plan Around Gestation Dates?
- Prepare housing, bedding, and birthing space well before the due date.
- Schedule veterinary checks and monitor the animal more closely as the date approaches.
- Plan feed and nutrition adjustments for the later stages of pregnancy.
- Reduce the risk of being caught off guard by an early or unexpected birth.
FAQs
Why do gestation lengths vary so much between species?
Gestation length is tied to the animal’s size, biology, and reproductive strategy — larger animals like horses and donkeys generally carry their young far longer than smaller livestock like rabbits or pigs.
Is the due date exact?
No — it’s an estimate based on typical averages for the species. Actual birth dates can vary by several days depending on the individual animal, breed, and health.