Abstract: Manual techniques for monitoring animal ovulation cycle have been used commercially to determine the best time to breed animals. Techniques using heat as an indicator for ovulation do not always correspond to ovulation. The present invention provides methods, apparatus, and kits for monitoring and predicting ovulation using an automated hand-held device, incorporating a computer and probe for detecting physical changes in the animal body fluid. Changes in electrolyte levels are detected as alterations in resistance which corresponds to specific intervals in the ovulation cycle. The present invention provides a rapid, low cost means for monitoring mammalian ovulation cycles and a tool for use in artificial insemination, especially in assessing large populations of animals.