This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by SKINNER, J. D. Articles by KARG, H. Search for Related Content PubMed PubMed Citation Articles by SKINNER, J. D. Articles by KARG, H.

THE POST-NATAL DEVELOPMENT OF THE REPRODUCTIVE TRACT OF THE SUFFOLK RAM, AND CHANGES IN THE GONADOTROPHIN CONTENT OF THE PITUITARY

Summary.: The growth of the pituitary and of the reproductive tract of Suffolk rams from birth to 168 days of age has been studied. Pituitary ICSH and FSH concentrations were determined by bio-assay. The pattern of testicular androgen production has been examined using chemical and histological techniques and the relationship to spermatogenesis studied. Pituitary gonadotrophin content increased sharply from 42 days of age but was only weakly correlated with other parameters measured. The androstenedione : testosterone ratio was at its narrowest at birth; however, testosterone was the predominant androgen from birth onwards. Androgen concentration fluctuated but the total content increased with increase in testicular weight. Fructose was present in the seminal vesicles from birth and citric acid from 14 days; citric acid concentration was about one-tenth that of fructose. There was a significant correlation between testicular androgen content and the fructose and citric acid concentration and content of the seminal vesicles. Seminiferous tubule diameter was significantly correlated with most of the parameters measured. Testicular weight increased sharply from 42 days of age. Androgen production was present at birth and preceded spermatogenesis which began when testis weight exceeded 10 g, which was after 56 days of age. Spermatozoa were present in the seminiferous tubules at 112 days of age.