The document discusses induction of parturition, or inducing labor, in animals. Induction of parturition may be recommended for reasons like unwanted pregnancy, fetal issues, or preventing difficulties during birth due to disproportion between the fetus and pelvis. The process is controlled by hormones in a feedback loop between the fetus, placenta, and mother. As gestation ends, cortisol from the fetal adrenal gland prepares the lungs, liver, and thyroid for birth. This affects the placenta to shift hormone production from progesterone to estrogen and prostaglandin F, which signals the corpus luteum to decrease progesterone. Once progesterone levels drop, contractions intensify, aided by oxytocin, to expel the fetus from