[Detection of embryonic mortality in cattle using sonography]

Area of Science:

• Veterinary Medicine
• Reproductive Biology
• Embryology

Background:

• Early embryonic mortality is a significant concern in cattle reproduction.
• Accurate detection of pregnancy and viability is crucial for herd management.
• Ultrasound and progesterone monitoring are established methods in bovine reproduction.

Purpose of the Study:

• To evaluate ultrasound parameters for detecting embryonic mortality in early pregnant cattle.
• To correlate embryonic and conceptus measurements with progesterone levels.
• To characterize the ultrasound appearance of embryonic death and subsequent events.

Main Methods:

• Ultrasound examinations (5 MHz-linear array scanner) were performed on 70 pregnant cattle on days 22, 25, 28, 35, and 42 post-insemination.
• Measurements included conceptus diameter, embryo size, and corpus luteum diameter.
• Milk progesterone levels were determined concurrently.

Main Results:

• Embryonic mortality occurred in 7 out of 70 cases (10%), detected by lack of embryonic heartbeat.
• Cows with embryonic mortality showed significant differences in conceptus and embryo sizes compared to viable pregnancies.
• Membranous and bubble-like structures were observed within the conceptus post-mortem.
• The corpus luteum persisted, and conceptuses were detectable until the next estrus, correlating with progesterone levels.

Conclusions:

• Ultrasound is effective in identifying early embryonic death in cattle.
• Changes in conceptus morphology and size are key indicators of embryonic mortality.
• Corpus luteum persistence and progesterone levels reflect the pregnancy status even after embryonic demise.