Testosterone-induced defeminization of behavior can occur from E18 up to 7 days postpartum.
The critical period for masculinization and/or defeminization in cattle may be between days 80 and 100 of the 284-day gestation period.
They apparently go through a defeminization process during adolescence.
Richard Pillard and James Weinrich suggest that there should be further differentiation of the neural influences on gender behavior because there are separate components of the nervous system that control masculinization and defeminization.
The remaining 2 per cent will be released from their jobs next fall when the final phase of the defeminization
legislation comes into effect.
Virilisation is a two phased process: first, there is defeminization
like development of oligomenorrhea or amenorrhea, regression of the breasts and external genitalia, atrophy of the uterus and adnexa, and loss of the female body contour; second, there is masculinization which includes hirsutism, acne, clitoral enlargement, increased libido, sterility, enlargement of the larynx, deepening of the voice, increased muscle mass and temporal alopecia.
The loss of feminine features during sexual differentiation.
The vaginal cytology of these animals confirmed that significantly more exposed females were acyclic by 6 months of age, an outcome that may be related to defeminization
of leutinizing hormone release (31).
Some of the effects reported include blocking of the effects of male hormones, resulting in the demasculinization of male offspring; antithyroid effects; alterations in the adrenal gland; decreased sperm count in male offspring; structural abnormalities in the external genitalia of female offspring and delayed puberty in the male; defeminization
and masculinization of female fish and birds; decreased hatching success in fish, birds, and turtles; decreased fertility in birds, fish, shellfish, and mammals; and gross birth deformities in birds, fish, and turtles (11-18).