Calculators

Health

What is Gestation?

Gestation is the period of fetal development from conception to birth in mammals. For birds, this period of development is called incubation. Incubation takes place in the egg, outside of the bird.

What influences the length of the gestation period across animals:

• Larger animals usually have longer pregnancies
• Animals born more able and independent have longer gestation periods
• Faster metabolism means faster fetal development
• Some breeding seasons time births with peak food availability

Using the Gestation Calculator

1. Choose your animal
2. Select Breeding Date to find due date, or select Due Date to find the breeding date
3. Enter your date
4. Adjust gestation period if needed
5. Click Calculate

Gestation for individual animals can vary. Veterinarian ultrasound measurements are most accurate to estimate gestational age, especially in early pregnancy.

For human pregnancies, use our Conception Calculator.

How to Calculate Due Dates and Breeding Dates

Calculate an Animal's Due Date

The formula for calculating due date is:

Due Date = Conception Date + Average Gestation Period

1. Find the average gestation period for the animal
2. Determine the breeding date, or date of service
3. Add the average gestation period to the breeding date to get the approximate due date

Example gestation calculation: Your dairy goats bred on October 22. Goat pregnancies typically last about 150 days.

• Due Date = Conception Date + Average Gestation Period
• Due Date = October 22 + 150 days = March 21

Breed an Animal for a Specific Due Date

If you want an animal to give birth on or around a specific date, calculate when to breed with this formula:

Breeding Date = Due Date − Average Gestation Period

1. Determine the target due date
2. Subtract the average gestation period for your animal to find the breeding date

Example breeding date calculation: You want to your rabbits to give birth on September 5. Rabbits have an average 32-day gestation period.

• Breeding Date = Due Date − Average Gestation Period
• Breeding Date = September 5 − 32 days = August 4

Note: Remember that some animals breed only during specific cycles or times of year, so you may need to adjust your dates accordingly.

The table below lists animals in this calculator, their gestation periods, and terms used to name their birthing process. To request another animal please contact us.

Why It's Important to Track Pregnancies in Herds and Flocks

Tracking pregnancy in farm animals helps farmers manage the health and care of both the mother and her offspring. Farmers need to provide proper nutrition, adjust living conditions, and monitor for complications. Pregnant animals often have different dietary and medical needs, and close observation can help prevent problems such as difficult births or illness. This improves the chances of healthy offspring and reduces the risk of loss.

Awareness of pregnancy timelines also helps farmers plan and run farm operations more efficiently. By knowing when animals are due to give birth, farmers can prepare space, arrange for assistance, and ensure they have resources like feed, labor, and medicine. Tracking pregnancies also allows for better record-keeping and breeding decisions, helping farmers maintain the strength of their herds over time.

Frequently Asked Questions