title: Reproductive characteristics and semen quality in maiden Dutch Warmblood stallions.
abstract: The semen characteristics and testicular size of 398 3-year-old maiden Dutch Warmblood stallions were studied during February and March. Mean values (+/- SD) of age (1030 +/- 88 days) and testicular size (9.8 +/- 0.9 cm) of the maiden stallions were determined as well as the following semen characteristics (mean of two ejaculates, taken 1 h apart): volume (65 +/- 26 ml), sperm concentration (2.061 +/- 1.685 x 10(8) ml-1), total number of spermatozoa (1.129 +/- 0.71 x 10(10)), percentage of progressively motile spermatozoa (68 +/- 9%), percentage of live spermatozoa with normal morphology (66 +/- 15%), total number of progressively motile morphologically normal spermatozoa (5.307 +/- 3.833 x 10(9)) and pH (7.5 +/- 0.2). The morphology of the spermatozoa was studied and data on the most common abnormalities are presented. The first and second ejaculates show significant differences (P < 0.05) in volume, motility, number of spermatozoa, sperm morphology, total number of progressively motile morphologically normal spermatozoa and pH. The original breed has been split up into two different lines. There was a significant difference (P < 0.05) in semen characteristics between the types (riding and carriage horses). The semen quality and quantity of semi-siblings were compared and a significant sire effect (P < 0.05) was shown for the following characteristics: volume, motility (%) and sperm concentration. These results indicate that there are differences of heritability of those factors, which makes it possible to select on semen quality.
authors.affiliation: Department of Herd Health and Reproduction, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Parlevliet
authors.forename: B
authors.initials: B
authors.lastname: Kemp
authors.forename: B
authors.initials: B
authors.lastname: Colenbrander
mesh_terms: D000818:Animals; D001947:Breeding; D005298:Fertility / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D012661:Semen / Q000502:physiology*; D013076:Sperm Count; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000166:cytology; D013737:Testis / Q000033:anatomy & histology*