1994 Volume 56 Issue 5 Pages 965-967
In order to determine relationships between the number of small follicles Prior to superovulatory treatment and superovulatory response, a total of 55 superovulations were induced in Holstein cows. The ovaries were examined ultrasonographically once 0-1.5 days before the initiation of superovulatory treatment. The number of small follicles 3-6mm in diameter on both ovaries before superovulatory treatment was found to be significantly correlated with the numbers of corpora lutea after superovulation (r=0.440, P < 0.001), total ova recovered (r=0.503, P < 0.001) and transferable embryos recovered (r=0.482, P < 0.001). These results indicate that a single ultrasonographic examination of follicles 3-6mm in diameter prior to superovulatory treatment can be utilized to Predict superovulatory response.