Pregnancy Diagnosis in Cattle — When to Check and What to Expect

You inseminated your cow three weeks ago. She did not return to heat. Is she pregnant?

Maybe. Cows can have silent heats — cycling without showing obvious signs. A cow that appears settled might not be pregnant at all, and if you assume she is without confirmation, you waste months waiting for a calf that is not coming.

Pregnancy diagnosis is not optional. It is the checkpoint that prevents false assumptions from derailing your breeding programme.

Why confirm pregnancy

The cost of an undiagnosed open cow is significant:

She consumes feed without progressing toward her next calving
She is not being rebred because you think she is pregnant
By the time you realise she is open — often when she does not calve when expected — you have lost 2-4 months of potential breeding time
Your calving interval stretches to 450+ days for that cow

A pregnancy check costs KES 300-500. The cost of not checking is KES 10,000-20,000 in delayed production.

Method 1: Non-return to heat

The simplest method: if a cow does not show heat signs 18-24 days after insemination, she may be pregnant. If she does not return by day 42 (two full cycles), the likelihood increases.

Pros:

Free
No vet visit required
Works well for cows with strong heat signs

Cons:

Silent heats are common (10-20% of cycles)
Detection depends on your observation quality
Not definitive until very late

Reliability: About 70-80% accurate. One in five "non-return" cows may actually be open.

When to use: As a first screen. If a cow does not return by day 24, consider her a candidate for confirmation but do not assume pregnancy.

Method 2: Rectal palpation

A trained veterinarian or AI technician inserts a gloved arm into the rectum and feels the uterus through the rectal wall. They can detect pregnancy by feeling the amniotic vesicle, the calf, or changes in the uterine horns.

When to do it: Day 35-45 post-insemination is the earliest reliable window. Day 60-90 is more definitive and easier for the examiner.

What the vet can tell you:

Pregnant or open
Approximate stage of pregnancy (early, mid, late)
Which horn the pregnancy is in
General uterine health

Pros:

Available in most areas of Kenya (county vets, private practitioners)
Relatively inexpensive (KES 300-500 per cow)
Results immediately
No equipment beyond gloves and lubricant

Cons:

Requires a skilled practitioner — accuracy depends on experience
Small risk of pregnancy loss if done too roughly or too early
Cannot detect twins reliably

Reliability: 95-98% accurate with an experienced practitioner at day 45+.

Method 3: Ultrasound

A vet uses a portable ultrasound probe (inserted rectally) to visualise the uterus on a screen. They can see the embryo, heartbeat, and amniotic fluid.

When to do it: As early as day 28-30 post-insemination. Most accurate at day 30-45.

What ultrasound can tell you:

Pregnant or open (definitive)
Embryo viability (heartbeat visible)
Twins (detectable from day 35)
Approximate stage with high precision
Calf sex (from day 55-65)

Pros:

Earliest definitive diagnosis
Can confirm viability (heartbeat)
Detects twins
Can sex the calf

Cons:

More expensive (KES 500-1,000 per cow)
Requires specialised equipment — not all vets have portable units
Availability may be limited in rural areas

Reliability: 97-99% accurate.

Method 4: Blood or milk progesterone testing

Progesterone levels rise during pregnancy. A blood or milk sample taken 21-24 days post-insemination can indicate whether progesterone is elevated.

Pros:

Can be done earlier than palpation
Does not require rectal examination

Cons:

Tests availability is limited in Kenya
High progesterone does not guarantee pregnancy (other conditions can cause elevated progesterone)
A negative result (low progesterone) is more reliable than a positive one

Reliability: Good for ruling out pregnancy (95% negative predictive value), less reliable for confirming it (75-85% positive predictive value).

When to use: If available, use as a screen at day 21-24 to quickly identify open cows. Follow up positives with palpation or ultrasound.

The recommended protocol for Kenyan dairy farmers

Based on cost, availability, and reliability in the Kenyan context:

Day 18-24: Watch for return to heat. If she shows heat, record it and plan rebreeding. If no return, proceed to step 2.

Day 35-45: Schedule a vet visit for rectal palpation (or ultrasound if available in your area). If pregnant — confirmed. Calculate expected calving date. If open — she needs rebreeding. Watch for the next heat and AI again.

Day 60-90 (optional): Second confirmation, especially for high-value cows. Catches the rare early embryonic loss (embryo dies after day 45 confirmation).

What to record

When the pregnancy check is done, record:

Date of check
Cow ID
Days post-insemination
Method (palpation, ultrasound, non-return)
Result (pregnant, open, inconclusive)
Vet or technician name
If pregnant: calculated calving date

This record closes the breeding loop. From insemination to confirmed pregnancy, every step is documented.

Early embryonic loss

About 5-10% of pregnancies confirmed at day 30-45 will be lost before day 90. The embryo dies and is reabsorbed. The cow returns to cycling but may not show obvious heat signs for several weeks.

This is why some farmers do a second pregnancy check at day 60-90 — it catches these losses early so the cow can be rebred without losing additional months.

If you notice a cow that was confirmed pregnant at day 40 showing heat signs at day 70-80, she likely lost the pregnancy. Record it, mourn briefly, and breed her again.

The cost of not checking

A single cow left undiagnosed for three extra months costs:

3 months of feed at maintenance rate: KES 7,200 (KES 80/day × 90 days)
3 months of lost breeding opportunity: pushes calving interval by 90 days
Impact on next lactation: late peak, compressed production

Total: approximately KES 15,000-25,000 in direct and opportunity costs.

The pregnancy check cost: KES 300-500.

The math speaks for itself.

Track every pregnancy check at shira.farm.