الطب البيطري veterinary medicine

📢 Early Pregnancy Diagnosis in Cows - "Milk Ejection Test" 🐄🍼

✅ Objectives:
🔹 Confirm pregnancy 20-22 days after insemination.
🔹 Reduce the service period duration.

🧪 Principle:
📍 PGF₂α (Dinoprost - Lutalyse) in a non-luteolytic dose triggers oxytocin release from the corpus luteum (CL).
📍 Oxytocin stimulates contraction of myoepithelial cells, leading to alveolar milk let-down in pregnant cows.

🔬 Procedure:
🔹 Step 1: Perform the test 3 hours before evening milking (18-22 days post-insemination).
🔹 Step 2: Insert a teat cannula into the left fore-teat to drain milk from the teat cistern.
🔹 Step 3: Once milk stops, administer 2.5 mg (0.5 ml) Dinoprost (Lutalyse) IV via the ear vein.
🔹 Step 4: If the cow is pregnant, alveolar milk will start flowing in about 1 minute.

🧑‍⚕️ Mechanism:
1️⃣ PGF₂α Injection → Stimulates oxytocin release from the corpus luteum (if present).
2️⃣ Oxytocin enters the bloodstream → Travels to the mammary gland.
3️⃣ Myoepithelial cells contract → Milk is ejected from alveoli into the milk ducts.
4️⃣ Milk flows from alveoli to teat canal → Pregnancy confirmed! ✅

🟢 Pregnant Cow:
✔️ CL is active → Oxytocin released → Alveolar milk flows ✅
🔴 Non-Pregnant Cow:
❌ CL regressed → No oxytocin release → No alveolar milk flow 🚫

📌 Simple, Quick & Effective Pregnancy Diagnosis