Cattle ultrasound can be used to estimate gestational age, monitor fetal growth, and diagnose pregnancy disorders. Various parts of the fetus such as the eyeball, stomach, ribs, etc. can be detected. To determine the development of each organ, the probe position should be adjusted to obtain the maximum scan section. The growth correlation coefficient of each tissue can also be calculated based on the gestational age. In short, the gestational age and its growth and development can be determined according to the size of each organ of the fetus, and the production period can be accurately predicted to facilitate production management.