title: Horn growth related to testosterone secretion in two wild Mediterranean ruminant species: the Spanish ibex (Capra pyrenaica hispanica) and European mouflon (Ovis orientalis musimon).
abstract: Seasonal variations in the horn development and testicular activity of the Spanish ibex (Capra pyrenaica hispanica) (n=6) and European mouflon (Ovis orientalis musimon) (n=5) were monitored to determine the role of increasing testosterone concentration on the arrest of horn growth during the rutting season. Marked seasonal variations in the rate of horn growth (P<0.01) and testicular activity (P<0.001) were seen in both species, although the magnitude and timing of these changes were different (P<0.01). Horn growth rate was inversely correlated to seasonal levels in testosterone plasma concentration in both species (ibex: R=-0.45, P<0.01; mouflon R=-0.51, P<0.01). In the mouflon, the increase in plasma testosterone concentration recorded in September (P<0.05 compared with the lowest concentration) coincided with a significant reduction in horn growth (P<0.05). In the ibex, the increase in plasma testosterone concentration in October (P<0.05 compared with the lowest concentration) was associated with a significant arrest of horn growth in November (P<0.05). These results appear to support the hypothesis that high peripheral plasma levels of testosterone are linked with the seasonal arrest of horn growth during the rutting period.
authors.affiliation: Dpto. Reproducción Animal, SGIT-INIA, Avda. Puerta de Hierro Km 5.9, 28040 Madrid, Spain. toledano@inia.es
authors.forename: A
authors.initials: A
authors.lastname: Toledano-Díaz
authors.forename: J
authors.initials: J
authors.lastname: Santiago-Moreno
authors.forename: A
authors.initials: A
authors.lastname: Gómez-Brunet
authors.forename: A
authors.initials: A
authors.lastname: Pulido-Pastor
authors.forename: A
authors.initials: A
authors.lastname: López-Sebastián
mesh_terms: D000818:Animals; D006041:Goats / Q000502:physiology*; D006733:Horns / Q000254:growth & development*; D008297:Male; D019083:Mediterranean Region; D012611:Scrotum / Q000033:anatomy & histology; D012621:Seasons; D012756:Sheep / Q000502:physiology*; D013739:Testosterone / Q000097:blood / Q000378:metabolism*
chemical_list: D013739:Testosterone