“…Scaramuzzi et al, 1971;Foster et al, 1975;Hauger et al, 1977). The LH surge is accompanied by behavioral estrus which precedes ovulation by approximately 24 h (McKenzie and Terrill, 1937;Robertson, 1967;Hauger et al, 1977). The role of follicle stimulating hormone (FSH) will not be considered here because of methodological problems in measurement of serum FSH and a paucity of definitive information concerning its physiological control by gonadal steroids.…”