His research interests are focused on the hormonal, cellular and molecular mechanisms regulating uterine development and uterine function during pregnancy using sheep, pigs and mice. These areas are funded by the USDA and NIH.

Spencer received a Bachelor's in Animal Science in 1989, and a Master's in Animal Science in 1992 from Auburn University. He received his Doctorate in Physiology of Reproduction in 1995 from Texas A&M University and completed postdoctoral studies at Baylor College of Medicine in molecular and cell biology in 1997.

Spencer is a member of the American Association for the Advancement of Science, Endocrine Society, Prenatal Research Society, Society for Reproduction and Fertility, Society for the Study of Reproduction, and Sigma Xi. He currently serves on the Editorial Boards of Biology of Reproduction, Reproduction, and Reproductive Biology and Endocrinology.

Spencer received a National Research Service Award from NIH in 1996, the Outstanding Young Animal Scientist Award-Research from the American Society of Animal Science in 2003, the New Investigator Award from the Society for the Study of Reproduction in 2004, the Sigma Xi Young Investigator Award in 2005, and the Texas A&M University Vice Chancellor's Awards in Excellence for Research On-campus and as a member of a research team in 2006.