Ultrasonogram of endometria in dairy cows. Diameters and areas of the endometria at the base of each uterine horn (approximately 5 cm anterior the uterine body) were measured and recorded by cross-sectional images. Note: If the structure of the scanned images was not spherical, the diameters of two 90° dimensions (a spot to b spot is the minor axis, c spot to d spot is the major axis) of uterine horns were averaged to obtain the values of diameters.