the hormone that is responsible for female secondary sex characteristics is called

The hormone responsible for the development of female secondary sex characteristics in farm animals is oestrogen (also spelled estrogen). Oestrogen is produced mainly by the ovaries (specifically the Graafian follicles) and is responsible for:

• Development of the mammary glands (udder development)
• Widening of the pelvic region
• Fat deposition in characteristic female patterns
• Development of the female reproductive tract
• Expression of oestrus (heat) behaviour

The other hormones have different roles:

• Progesterone is produced by the corpus luteum after ovulation. Its primary function is to prepare and maintain the uterus for pregnancy, not to develop secondary sex characteristics.
• Testosterone is the male sex hormone responsible for male secondary sex characteristics such as muscular development, aggression, and libido in males.
• Relaxin is a hormone produced during late pregnancy that relaxes the pelvic ligaments and softens the cervix to facilitate parturition (birth).

Exam tip: Oestrogen = female secondary sex characteristics and heat behaviour. Progesterone = pregnancy maintenance. Testosterone = male traits. Relaxin = birth preparation.