The Ovary data frame has 308 rows and 3 columns.
This data frame contains the following columns:
an ordered factor indicating the mare on which the measurement is made.
time in the estrus cycle. The data were recorded daily from 3 days before ovulation until 3 days after the next ovulation. The measurement times for each mare are scaled so that the ovulations for each mare occur at times 0 and 1.
the number of ovarian follicles greater than 10 mm in diameter.
Pierson and Ginther (1987) report on a study of the number of large ovarian follicles detected in different mares at several times in their estrus cycles.