Fig. 5.

Biological events associated with AI timing of sorted sperm composed of subpopulations categorized on the basis of kinematic parameters and trajectory patterns. (A) Conception rates of cows related to AI timing after estrus onset. The categorical variables were compared using the χ² test. P < 0.05 were considered statistically significant. Bars without a common superscript differed (P < 0.05). (B) Correlation between PN and TS subpopulations and pregnancy with respect to AI timing. Nonreturn rates 40 and 60 d after AI were recorded. Red arrows indicate pregnancy with inseminate containing only 30% TS at later AI (24 and 27 h after estrus onset). Green arrows indicate pregnancy of Japanese Black heifers in natural estrus inseminated following the AM–PM rule. (C) A guide to time relationships among reproductive events and fertile lifespan of bovine spermatozoa and oocyte.