The growth and retrogression of the corpus lutuem in the ewe

Abstract

Data obtained from 35 Peppin Merino ewes were used to describe the growth and retrogression of the corpus luteum. The growth period between one day and eight days after ovulation is described by the regression Y = 2.524 + 2.254x - 0.144x2 and the retrogressive period between 14 days and 25 days after ovulation by Y = 47.128 - 3.707x + 0.080x2 where Y = diameter of corpus luteum in millimeters and x = time in days. The possible use of this data is discussed.