Temporal variations of LH and testosterone in arabian oryx (Oryx leucoryx) from birth to adulthood.

To determine the onset of puberty in Arabian oryx (Oryx leucoryx), a longitudinal study was conducted in 5 captive males at the National Wildlife Research Centre, Taif (Saudi Arabia). From birth to 20 months of age, twice weekly, animals were weighed and blood was assayed for LH and testosterone. Four periods were defined by analysis of the hormonal profile. During the first 5 months (corresponding to prepuberty), mean LH concentrations increased significantly while testosterone remained basal. Testosterone increased significantly during the second period (from 6 to 7 months) while LH decreased significantly. The testosterone pattern suggests that the animals reached puberty at around 7 months old. Mean LH concentrations remained at a similar level before and after puberty and increased significantly between the 12th and 13th months of life. This increment correspond to the transition between two further periods. The third period (8-12 months) was characterized by testosterone peaks of 2.4 +/- 0.1 ng ml-1 which irregularly occurred over a period of 26.6 +/- 2.7 days and was followed by a fourth period, during which peaks were seen at 24.1 +/- 1.6-day intervals and reached 4.7 +/- 0.2 ng ml-1. This last period probably corresponds to the mature stage of puberty. The testosterone cyclicity in oryx, coinciding with the estrous cycle length of the female, would permit the male to be fertile throughout the year and could be an adaptive response to the opportunistic and aseasonal reproductive cycle of the female.

[1]  M. Ancrenaz,et al.  The presence of the male stimulates puberty in captive female Arabian oryx (Oryx leucoryxPallas, 1777)☆ , 1997 .

[2]  M. Ancrenaz,et al.  Length of estrous cycle and gestation in the Arabian oryx (Oryx leucoryx) and the importance of the male presence for induction of postpartum estrus. , 1996, General and comparative endocrinology.

[3]  A. Greth,et al.  An outbreak of tuberculosis in a captive herd of Arabian oryx (Oryx leucoryx): management , 1994, Veterinary Record.

[4]  A. Burny,et al.  Changes in the hypophysial-gonadal axis during the onset of puberty in young bulls. , 1993, Journal of reproduction and fertility.

[5]  M. Ancrenaz,et al.  Hand‐rearing the Arabian oryx Oryx leucoryx: at the National Wildlife Research Center, Saudi Arabia , 1993 .

[6]  R. Mauget,et al.  Influence of photoperiod on the seasonal pattern of secretion of luteinizing hormone and testosterone and on the antler cycle in roe deer (Capreolus capreolus). , 1992, Journal of reproduction and fertility.

[7]  J. Brown,et al.  Seasonal variation in pituitary-gonadal function in free-ranging impala (Aepyceros melampus). , 1991, Journal of reproduction and fertility.

[8]  D. Kleiman Animal re-introductions: The Arabian oryx in Oman: Mark R. Stanley Price, Cambridge University Press (Cambridge Studies in Applied Ecology and Resource Management), 1989. £17.50 hbk (xix + 291 pages) ISBN 0 521 34411 5 , 1990 .

[9]  Daniel Portetelle,et al.  Evolution des concentrations plasmatiques de testostérone et d'insulin-like growth factor I en période péripubertaire chez le bovin cathétérisé au niveau hépatique. , 1990 .

[10]  N. Wayne,et al.  Regulation of the onset of the breeding season of the ewe: importance of long days and of an endogenous reproductive rhythm. , 1989, The Journal of endocrinology.

[11]  A. Dixon Conservation and Biology of Desert Antelopes , 1989 .

[12]  T. Petit,et al.  Croissance de l’oryx d’Arabie , 1989 .

[13]  J. Brown,et al.  Endocrine profiles, testicular gonadotropin receptors and sperm production in hemi-castrated ram lambs. , 1987, Journal of animal science.

[14]  J. Boissin,et al.  Seasonal changes in testis weight and testosterone concentration in the european wild boar (Sus scrofa L.) , 1987 .

[15]  B. Howland,et al.  Seasonal changes in the endocrine responsiveness of the pituitary and tests of male sheep in relation to their patterns of gonadotropic hormone and testosterone secretion. , 1984, Canadian journal of physiology and pharmacology.

[16]  A. Burny,et al.  Testosterone plasma profiles, as a function of age in young bulls from the bovine double-muscled Belgian white blue breed a preliminary report. , 1983, Theriogenology.

[17]  A. Lacroix,et al.  Temporal and seasonal relationships between LH, testosterone and antlers in fawn and adult male roe deer (Capreolus capreolus L.): a longitudinal study from birth to four years of age. , 1982, Acta endocrinologica.

[18]  M. Thibier,et al.  LH and testosterone responses to gonadoliberin (LRH) treatment in young bulls prior to and during puberty , 1979 .

[19]  A. Lacroix,et al.  Short-term variations in plasma LH and testosterone in bull calves from birth to 1 year of age. , 1979, Journal of reproduction and fertility.

[20]  D. Lunstra,et al.  Puberty in beef bulls: hormone concentrations, growth, testicular development, sperm production and sexual aggressiveness in bulls of different breeds. , 1978, Journal of animal science.

[21]  A. Lacroix,et al.  Temporal fluctuations of plasma LH and testosterone in Charolais bull calves during the first year of life , 1977 .

[22]  P. Secchiari,et al.  Variation of plasma testosterone in developing Friesian bulls. , 1976, Journal of animal science.

[23]  J. Findlay,et al.  Regulation of gonadotrophin secretion in rams from birth to sexual maturity. I. Plasma LH, FSH and testosterone levels. , 1976, Journal of reproduction and fertility.

[24]  J. Findlay,et al.  Regulation of gonadotrophin secretion in rams from birth to sexual maturity. II. Response of the pituitary-testicular axis to LH-RH infusion. , 1976, Journal of reproduction and fertility.

[25]  M. Thibier Peripheral plasma testosterone concentrations in bulls around puberty. , 1975, Journal of reproduction and fertility.

[26]  A. Caraty,et al.  VARIATIONS IN PITUITARY AND BLOOD LH DURING PUBERTY IN THE MALE LAMB. RELATION TO TIME OF BIRTH , 1975 .

[27]  D. Henderson Were They the Last Arabian Oryx? , 1974, Oryx.

[28]  B. W. Pickett,et al.  Regulation of blood levels of LH in bulls: influence of age, breed, sexual stimulation and temporal fluctuations. , 1973, Journal of reproduction and fertility.

[29]  L. Swanson,et al.  Testicular and blood plasma androgens in Holstein bulls from birth through puberty. , 1972, Journal of animal science.