Effects of oxygen exposure and gentamicin on stallion semen stored at 5 and 15 degrees C.
This study was undertaken to investigate the effects of storage of stallion semen in a defined milk protein extender at 5 and 15 degrees C under either anaerobic or aerobic conditions, with or without addition of the antibiotic gentamicin. Semen samples were collected from eight fertile stallions and stored for 96 h (day 0-4) and assessed daily for motility, velocity and membrane integrity (viability) using a CASA system. Samples for bacteriology assessment were taken on day 2 of storage. No significant (p > 0.05) differences in motility, velocity or viability were observed between treatments on days 0-2. On days 3 and 4, semen stored without gentamicin at 5 degrees C had a significantly (p < 0.05) better semen quality compared with storage at 15 degrees C without gentamicin, irrespective of oxygen exposure. On days 3 and 4, motility and velocity were greater in samples stored at 15 degrees C with gentamicin, compared with the corresponding treatments without antibiotic (p < 0.05). This effect was also evident for viability on day 4. The decline in semen quality observed at 15 degrees C most likely resulted from the effect of bacterial growth. Bacterial growth was the greatest in samples stored at 15 degrees C without gentamicin, under both anaerobic and aerobic conditions (p < 0.05). Bacterial growth was inhibited by adding of gentamicin at 15 degrees C, which accordingly reduced the decline in semen quality. Addition of antibiotic to samples stored at 5 degrees C had no significant effect on any parameter analysed. In conclusion, storage at 15 degrees C can be achieved by using an extender containing the antibiotic gentamicin. Storage at 5 degrees C tended to maintain better semen quality irrespective of oxygen exposure, and did not necessitate an antibiotic treatment.
Centre for Artificial Insemination and Embryo Transfer, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, AustriaInstitute of Rural Sciences, University of Wales, Aberystwyth, UKClinic for Obstetrics, Gynaecology and Andrology, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, Austria.
S
S
Price
Centre for Artificial Insemination and Embryo Transfer, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, AustriaInstitute of Rural Sciences, University of Wales, Aberystwyth, UKClinic for Obstetrics, Gynaecology and Andrology, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, Austria.
J
J
Aurich
Centre for Artificial Insemination and Embryo Transfer, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, AustriaInstitute of Rural Sciences, University of Wales, Aberystwyth, UKClinic for Obstetrics, Gynaecology and Andrology, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, Austria.
M
M
Davies-Morel
Centre for Artificial Insemination and Embryo Transfer, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, AustriaInstitute of Rural Sciences, University of Wales, Aberystwyth, UKClinic for Obstetrics, Gynaecology and Andrology, Department of Animal Breeding and Reproduction, University of Veterinary Sciences, Vienna, Austria.
C
C
Aurich
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000254:growth & development*; D002470:Cell Survival; D015169:Colony Count, Microbial; D005839:Gentamicins / Q000494:pharmacology*; D006736:Horses; D008297:Male; D010100:Oxygen / Q000494:pharmacology*; D011897:Random Allocation; D012661:Semen / Q000187:drug effects* / Q000382:microbiology / Q000502:physiology; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility; D013696:Temperature; D013997:Time Factors
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D010100:Oxygen