Semen production in two rabbit lines divergently selected for 63-d body weight.
Thirty-one bucks from two lines divergently selected for 63-d body weight (low, L and high, H) were solicited every week (twice at a 15min interval) during 18 weeks resulting in 482 ejaculates. While differing markedly on adult body weight (L: 4650g versus H: 5925g), both lines had the same testis weight. Libido did not differ between the lines. The proportion of ejaculates suitable for insemination was markedly higher in the L line (66.5% versus 44.2%). Mass motility and the volume of the ejaculates were higher in the L line while the sperm concentration was higher in the H line. Overall, the total number of spermatozoa per ejaculate was similar in both lines but the efficient number of spermatozoa per ejaculate, a synthetic criterion taking into account the ability of the ejaculate for insemination was higher in the L line (229 versus 170x10(6)). The L line had higher values of average path velocity, linearity and curvilinear velocity but a lower value of beat cross frequency. In the L line, both ejaculates had the same concentration, while in the H line, the first ejaculate was more concentrated than the second one. Some male reproductive traits are therefore genetically related to body weight.
Brun
Jean-Michel
JM
INRA, Station d'Amélioration Génétique des Animaux, BP 52627, 31326 Castanet Tolosan Cedex, France. Jean-Michel.Brun@toulouse.inra.fr
Theau-Clément
Michèle
M
Esparbié
Jean
J
Falières
Jacky
J
Saleil
Georges
G
Larzul
Catherine
C
D000818:Animals; D001835:Body Weight / Q000235:genetics* / Q000502:physiology; D001947:Breeding; D004542:Ejaculation; D008297:Male; D009929:Organ Size; D011817:Rabbits / Q000235:genetics / Q000502:physiology; D012661:Semen / Q000166:cytology / Q000502:physiology*; D013076:Sperm Count / Q000662:veterinary; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D013737:Testis / Q000033:anatomy & histology / Q000502:physiology