The Master of Science Seminar and Examination of Nicole Sugai

Biography

Dr. Nicole Sugai received her bachelor’s degree in double majors of biology and evolutionary anthropology at the University of Michigan. She completed her veterinary degree, with honors, at the University of Illinois at Urbana-Champaign College of Veterinary Medicine. After two years in general practice, Dr. Sugai returned to academia for a small animal focused residency at Virginia-Maryland College of Veterinary medicine. She will complete her residency in July 2024.

Funded by

• Jo’Anne O’Brien Endowment
• American Kennel Club/Canine Health Foundation/Theriogenology Foundation residency program 
• Virginia-Maryland College of Veterinary Medicine Office of Research and Graduate Studies

Awards and Academic Achievements

• BMVS graduate student of the year 2022

Lay Language Abstract 

Artificial insemination is a growing industry for canine reproductive medicine.  Processing canine semen is necessary for preparation of cooled shipments or cryopreservation. However, the techniques are not well understood for canine andrology. Our goal was to define an acceptable range of centrifugation and concentration parameters (gravitational (g) force and time) without severe negative impact on semen quality. In the first experiment, we hypothesized that higher g force (900g vs. 400g or 720g) and longer treatment (10 min. vs. 5 min.) improves sperm recovery rates yet causes larger magnitude of decline in semen parameters over a 48-hour cooling period. Initial raw semen evaluations served as each dog’s own control. Sperm recovery rates post-centrifugation were similar between treatment groups. Sperm viability, motility and morphology was not different between centrifugation treatment groups but declined over time. In conclusion, a range of 400-900g for 5-10 minutes centrifugation provides clinically viable semen quality after up to 48 hours of cooled storage in dogs. 

In the second phase, we compared different sperm concentrations for cooled canine semen storage and hypothesized that lower concentrations would result in better semen quality. Individual ejaculates were divided into a control aliquot (CON) extended 1:3 vol:vol with a commercial extender. The remaining sample was centrifuged and extended to 200 x106 sperm/ml (C200), then serially diluted to 100, 50, and 25 x106 sperm/ml concentrations (C100-C25). Aliquots were cooled for 24h, then centrifuged and re-extended. Cooling resulted in significant declines in subjective total motility and normal morphology (NM, %) for all groups, and in decreased viability for CON and C25-50. After cooling, viability was significantly lower for C25 compared to all groups, and higher for CON compared to C25-100 (P≤0.038). For motility parameters and NM, C25 performed worse than all or most of the other groups. In conclusion, our results show that cooling canine semen for 24h at 200 x106 sperm/ml final concentration after processing, or extending 1:3 vol:vol without centrifugation is preferred based on highest PMI. If volume restrictions apply, processing raw semen and extending to the desired volume with higher sperm concentrations at the collection facility is superior to centrifugation and volume adjustment after 24h of cooled storage.

Publications

• Sugai, N., Werre, S., Cecere, J., & Balogh, O. Comparing different sperm concentrations for optimizing cooled semen use in the dog. Frontiers in Veterinary Science, 10, 1339840. doi: 10.3389/fvets.2023.1339840 
• Cecere J., & Sugai N. (2023). Canine semen processing for chilled shipment. Clinical Theriogenology, 15. https://doi.org/10.58292/ct.v15.10227
• Sugai, N., Cecere, J., and Balogh, O., “Oral Communications 1.6-Comparing different sperm concentrations for cooled semen shipment in dogs,” Reproduction of Domestic Animals Vol 58, Issue S2 (Special Issue: 1st European Symposium on Animal Reproduction, 21st-23rd September 2023, Nantes, France) September 2023. pg 184-198. https://doi.org/10.1111/rda.14440
• Sugai, N., Cecere, J., and Balogh, O., “Comparing semen concentration for cooled semen use in the dog,” Proceedings of Society for Theriogenology July 2023
• Sugai N, Werre S, Cecere J, Balogh O. Defining an Optimal Range of Centrifugation Parameters for Canine Semen Processing. Animals (Basel). 2023 Apr 21;13(8):1421. doi: 10.3390/ani13081421. PMID: 37106983; PMCID: PMC10135290.
• Sugai, N., Cecere, J., and Balogh, O., “Optimizing centrifugation for cooled canine semen processing: preliminary data,” Proceedings of Society for Theriogenology, July 2022. 

Presentations

• European Symposium on Animal Reproduction 2023
• Society for Theriogenology 2022 and 2023 
• Small Animal Intern/resident seminar in 2022 and 2023

Examination Graduate Committee

Major Advisor/Chair:

James Weger-Lucarelli, PhD
Assistant Professor
Department of Biomedical Sciences and Pathobiology VA-MD College of Veterinary Medicine 

Graduate Advising Committee Members:

Sally L. Paulson, PhD
Associate Professor
Veterinary and Medical Entomology

Nisha K. Duggal, PhD
Associate Professor
Department of Biomedical Sciences and Pathobiology VA-MD College of Veterinary Medicine

Tanya LeRoith, DVM, PhD, DACVP
Clinical Professor
Department of Biomedical Sciences and Pathobiology VA-MD College of Veterinary Medicine