title: Temperatures from 4 to 15 °C are suitable for preserving the fertilizing capacity of stallion semen stored for 22 h or more in INRA96 extender.
abstract: This study tested whether variable temperatures (from -0.5 to 15 °C) and air exposure could be used under laboratory and under field conditions to store stallion sperm diluted in extender INRA96 without loss of fertility. Experiment 1 (laboratory conditions) measured the effects of two 72 h storage conditions (5 °C with air vs. 15 °C without air). Experiment 2 (fixed field conditions) measured the effects of 22 h of storage without air in disposable containers maintained at four ambient temperatures (7 °C, 17 °C, 27 °C, 39 °C with semen at -0.5 °C to 3 °C, 4 °C to 7 °C, 8 °C to 10 °C, 12 °C to 15 °C, respectively). Per cycle pregnancy rate (PC) was measured after one artificial insemination (AI) in uterine body of 200×10(6) total spermatozoa, 7 h (Experiment 1) or 17 h (Experiment 2) before ovulation. In Experiment 1, PC was similar for both conditions (60% (n=40 cycles) vs. 63% (n=40), respectively, 5 stallions×8 cycles). Only velocity VCL and ALH were slightly higher at 15 °C. In Experiment 2, PC was reduced when ambient temperature was low (semen at -0.5 °C to 3 °C; PC=25%) rather than intermediate (semen at 4 °C to 7 °C; PC=53%) or high (semen at 8 °C to 10 °C; PC=50%) (4 stallions×8 cycles) (P=0.002). Sperm stored at -0.5 °C to 3 °C had lower acrosome integrity/responsiveness, similar membrane integrity (HOS test) and motilities, and higher VCL and ALH, than semen stored between 4 and 15 °C. These results demonstrate a wide tolerance of equine sperm to variable positive temperatures and air exposure for 22 h storage and more. However, temperatures close to 0 °C are detrimental for fertility.
authors.affiliation: INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France. marianne.vidament@tours.inra.fr
authors.forename: Marianne
authors.initials: M
authors.lastname: Vidament
authors.forename: Michèle
authors.initials: M
authors.lastname: Magistrini
authors.forename: Yoann
authors.initials: Y
authors.lastname: Le Foll
authors.forename: Nicolas
authors.initials: N
authors.lastname: Levillain
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Yvon
authors.forename: Guy
authors.initials: G
authors.lastname: Duchamp
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Blesbois
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary; D003451:Cryoprotective Agents / Q000494:pharmacology*; D005260:Female; D005298:Fertility; D006736:Horses / Q000502:physiology*; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D012661:Semen / Q000187:drug effects*; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology; D013696:Temperature
chemical_list: D003451:Cryoprotective Agents