DELAYED OVULATION VS SILENT HEAT

Silent heat is characterized by ovulation occurring at the normal physiological time in the absence of overt estrus behavior [28]. Endocrine events, including the LH surge, are normal; the absence of behavioral signs such as mounting, vocalization, or vulvar edema is the distinguishing feature [4].

In contrast, delayed ovulation involves endocrine disruption with a postponed or attenuated LH surge, resulting in delayed oocyte release, even if estrus behavior may be present, prolonged, or irregular [2]. Thus, silent heat primarily reflects altered estrus expression, whereas delayed ovulation reflects impaired ovulatory physiology. Failure to differentiate these can lead to inappropriate interventions: silent heat benefits from improved estrus detection (e.g., activity sensors, progesterone monitoring), while delayed ovulation requires targeted hormonal or metabolic therapy to restore normal ovulatory timing [17].