Bovine Pregnancy Diagnosis Calculator

Estimate calving date, fetal size, and gestational stage from breeding date, breed, and palpation findings.

Inputs

Days since breeding/AI

Breed

Palpation-estimated days (0 = skip)

Herd size

Tab to move between fields

Results

Days until calving

223

Current trimester1

Gestation progress (%)21.2%

Est. fetal length (cm)10

Est. fetal weight (kg)0.13

Expected birth weight (kg)35

Breed gestation length (days)283

How to Use This Calculator

Enter Days since breeding/AI, Breed, and Palpation-estimated days (0 = skip).
Set Herd size.
Review the Days until calving result.
Use Current trimester and Gestation progress (%) (%) to inform your decision.

How the result changes with Days since breeding/AI

Days since breeding/AI	Days until calving
30	253
105	178
195	88
270	13

What each input means

Days since breeding/AI: Number of days since natural service or artificial insemination.
Breed: 0 = Holstein (280d), 1 = Jersey (279d), 2 = Angus (283d), 3 = Hereford (285d), 4 = Brahman (292d).
Palpation-estimated days (0 = skip): If rectal palpation was performed, enter estimated gestation day. Enter 0 to use breeding date only.
Herd size: Number of cows in the herd (for reference).

What each result means

Days until calving: Estimated days remaining until expected calving date.
Current trimester: Gestational trimester: 1 (0-93d), 2 (94-186d), or 3 (187d+).
Gestation progress (%): Percentage of gestation completed.
Est. fetal length (cm): Estimated crown-rump fetal length based on gestational age.
Est. fetal weight (kg): Estimated current fetal weight.
Expected birth weight (kg): Typical birth weight for the selected breed.
Breed gestation length (days): Average gestation length for the selected breed.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Days since breeding/AI = 60, Breed = 2, Palpation-estimated days (0 = skip) = 0, Herd size = 100 = 4 input(s) provided
Calculate Days until calving
Days until calving
223 = 223
Calculate Current trimester
Current trimester = 1 (0-93d)
1 = 1
Calculate Gestation progress
Gestation progress = min(100, (estimatedGestationDay / gestationLength) * 100)
21.2 = 21.2%

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