Core A – Husbandry and Management Core: Project Summary ONPRC Expanded SPF (eSPF) rhesus macaques (Macaca mulatta) are defined as being negative for rhesus rhadinovirus, simian immunodeficiency virus, simian foamy virus, simian T-lymphotropic virus, simian retrovirus, macacine herpesvirus-1, measles, and rhesus cytomegalovirus. They are critical for the study of opportunistic viruses impacting HIV infected patients. eSPF macaques are a premier animal model for HIV/AIDS research, including studies on HIV pathogenesis, AIDS-related opportunistic infections, and the development of HIV treatments and vaccines. With the rapid expansion of infectious disease research programs, the national need for genetically characterized eSPF rhesus macaques for HIV/AIDS research continues to exceed current availability. It is imperative that the available eSPF rhesus macaque colonies continue to expand to support this research and the advancement of human health. The successful maintenance of eSPF colonies requires strict barrier management practices in order to remain specific pathogen free. With over 22 years' experience in maintaining a colony of eSPF animals, the ONPRC is a leader in managing eSPF rhesus macaques. The overall aims of the Husbandry and Management Core are to expand the ONPRC eSPF breeding colony to meet existing and future animal resource demands, continue to refine existing exemplary eSPF husbandry and veterinary care, and to diversify the eSPF resource by increasing successful recruitment of genetically valuable animals in our breeding colony. To ensure the continued success of this program, we will utilize a collaborative, team-based approach to management practices including further expansion of the colony into outdoor sheltered housing, diversification of the time- mated breeding program, stable male/female pairs, assisted reproductive techniques, growth of the foster dam program for abandoned infants, and rederivation of infants from the ONPRC SPF4 colony.