Programs for fixed-time artificial insemination in South American beef cattle

Area of Science:

• Reproductive Biology
• Animal Science
• Veterinary Medicine

Background:

• Fixed-time artificial insemination (FTAI) is crucial for genetic improvement in South American beef herds.
• Traditional FTAI protocols utilize progesterone (P4) and estradiol for synchronization, achieving 40-60% pregnancies per AI (P/AI).

Purpose of the Study:

• To review advancements in FTAI protocols for beef cattle.
• To highlight the impact of extended follicular development intervals and sexed semen on P/AI.
• To discuss the role of Doppler ultrasonography in early pregnancy detection and re-synchronization.

Main Methods:

• Review of recent FTAI protocols in South American beef cattle.
• Analysis of strategies including extended intervals from device removal to FTAI.
• Incorporation of sexed-sorted semen and Doppler ultrasonography for pregnancy diagnosis.

Main Results:

• Modified FTAI protocols extending the ovulatory follicle growth period show improved P/AI.
• Sexed-sorted semen can be effectively used with FTAI protocols in beef cattle.
• Early pregnancy detection (Day 22) using Doppler ultrasonography enables efficient re-synchronization for a second FTAI.

Conclusions:

• FTAI protocols have revolutionized AI adoption in South American beef production.
• These protocols enable synchronized insemination and re-insemination, maximizing conception rates within a defined breeding season.
• FTAI eliminates the need for clean-up bulls, ensuring high pregnancy rates and efficient herd management.