Serum Estrogen Concentrations during Postnatal Development in Male Pigs

Abstract

Serum concentrations of estrone (E₁), estradiol (E₂), estrone sulfate (E,S), and testosterone (T) were quantified in male pigs at 10 ages from 2 weeks to 2 years. Changes in the concentrations of all four of these hormones were characterized by elevated amounts during neonatal development (1 to 3 weeks of age), a nadir for concentration of each hormone between 1 and 3 months of age, an increase during pubertal development with maximal concentrations at 8 months of age, and no further change by 2 years of age. E₁S was predominant of the three estrogens at all age groups with mean concentrations that ranged from 2 to 33 ng/ml. E₁ was present in higher concentrations during neonatal development than E₂, whereas the reverse situation was observed after 4 months of age. Observations from the present study indicate that early neonatal and pubertal development in male pigs are associated with elevated serum estrogen concentrations.