Abstract
The goals of this study are to use EIA kits to determine relations between changes in plasma LH concentration and plasma gestagen concentration and to investigate the usefulness of gestagen-concentration measurements by EIA kit in estimating optimal mating time. Blood samples were taken once daily from beagle bitches from the first day of proestrus to7 days after mating. The LH and gestagen concentrations of plasma samples were measured by RIA and EIA kit, respectively. Plasma gestagen concentrations began rising from basal levels at the start of the LH preovulatory surge and continued increasing until10 days after the LH surge. Relationships between the peak time of the LH preovulatory surge and changes in plasma gestagen concentration were determined, and an optimal mating-time guide indicating these relationships was drawn up. Reproductive performances in the experimental group (n=14) mated once in accordance with this guide and the control group (n=54) were similar. These results indicate that measurement of plasma gestagen concentration with an EIA kit is useful in estimating optimal mating time.
