Development of a Portable Device-Based Method for Predicting Follicle Number Using Vulvar Blood Flow Volume
Megumi Nagahara1, Takeshige Otoi1,2, Momo Nakagawa3
1Bio-Innovation Research Center, Tokushima University, Tokushima, Japan.
Animal Science Journal = Nihon Chikusan Gakkaiho
|January 6, 2026
Summary
Vulvar blood flow volume (BFV) can predict follicle numbers in cows. This non-invasive method correlates with estradiol levels, aiding superior cattle selection for beef and milk production.
Area of Science:
- Reproductive biology
- Veterinary science
- Animal breeding
Background:
- Embryo recovery and transfer are key for selecting superior cattle.
- Accurate prediction of follicle number is crucial for efficient breeding programs.
Purpose of the Study:
- To evaluate vulvar blood flow volume (BFV) using a portable meter.
- To determine if BFV can predict follicle number in cows.
- To explore the relationship between BFV, hormone dynamics, and follicle count.
Main Methods:
- Eleven Japanese Black cows were treated with superovulation.
- Vulvar BFV, serum estradiol (E2), progesterone, and follicle numbers were measured.
- Measurements were taken during the luteal phase, pre-estrus, and post-estrus.
Main Results:
- Vulvar BFV significantly increased one day before estrus compared to the luteal phase.
- BFV dynamics paralleled follicle number and serum E2 levels.
- Positive correlations were found between BFV and follicle number, E2 and follicle number, and BFV and E2.
Conclusions:
- Vulvar BFV measurement is a practical, non-invasive method for predicting follicle number.
- BFV offers a valuable tool for farmers in cattle selection.
- This technique supports efficient breeding for beef and milk production.
