title: Testosterone concentrations, testes weight and morphology of mule drakes (Muscovy drake x Khaki Campbell).
abstract: 1. Mule ducks were produced by naturally mating Muscovy drakes and Khaki Campbell ducks. 2. Semen was collected from 6-month-old mule drakes via an artificial vagina. The fluid was clear without any spermatozoa or spermatids. 3. Testes from 27-week-old mule drakes were smaller in size than those of Khaki Campbell drakes but heavier than Muscovy males of the same age. Histological sections of these testes revealed that spermatogenesis was not complete. 4. Testosterone concentration in the mule drakes was higher than in Muscovy males but similar to Khaki Campbell drakes. 5. Mule drakes have strong sexual drives as a result of high concentrations of testosterone, but, because spermatogenesis is incomplete, their semen had no sperm.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Hebrew University of Jerusalem, Israel.
authors.forename: N
authors.initials: N
authors.lastname: Snapir
authors.forename: J
authors.initials: J
authors.lastname: Rulf
authors.forename: A
authors.initials: A
authors.lastname: Meltzer
authors.forename: G
authors.initials: G
authors.lastname: Gvaryahu
authors.forename: I
authors.initials: I
authors.lastname: Rozenboim
authors.forename: B
authors.initials: B
authors.lastname: Robinzon
mesh_terms: D000375:Aging; D000818:Animals; D003433:Crosses, Genetic; D004372:Ducks / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D007248:Infertility, Male / Q000235:genetics / Q000662:veterinary; D008297:Male; D009929:Organ Size; D012726:Sexual Behavior, Animal; D012741:Sexual Maturation; D013045:Species Specificity; D013091:Spermatogenesis; D013737:Testis / Q000033:anatomy & histology*; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone