Estrus Detection and Optimal Insemination Timing in Holstein Cattle Using a Neck-Mounted Accelerometer Sensor System.

Area of Science:

• Veterinary Science
• Animal Reproduction
• Dairy Management

Background:

• Estrus detection is crucial for efficient dairy herd reproductive management.
• Accurate timing of artificial insemination (AI) maximizes conception rates.
• Novel technologies like accelerometer-equipped collars can improve estrus detection accuracy.

Purpose of the Study:

• To evaluate the accuracy of the RUMI collar for estrus detection in dairy cows.
• To establish an optimal timing recommendation for AI using the RUMI collar.
• To characterize ovarian blood flow and luteal activity preceding ovulation.

Main Methods:

• Forty-seven cycling dairy cows were monitored using the RUMI collar for estrus detection.
• Ultrasound examinations assessed ovarian and uterine changes every 12 hours.
• Blood samples measured progesterone levels; ANOVA analyzed physiological parameters.

Main Results:

• The RUMI collar showed high accuracy (93.62%), specificity (100%), and sensitivity (90.90%) for estrus detection.
• The optimal AI window was determined to be 11.4 to 15.5 hours post-estrus onset.
• Increased follicular blood flow and decreased luteal activity were observed 48 hours before ovulation.

Conclusions:

• The RUMI collar is a reliable tool for estrus detection in dairy cows.
• The identified AI window can optimize insemination timing for improved reproductive efficiency.
• Further studies are needed to validate conception rates and external factor influences on the AI window.