Project Summary/ Abstract The AIDS research portfolio at Yerkes National Primate Research Center (YNPRC) has continued to expand as demonstrated by a peak growth of approximately $6.5 million dollars (30% increase) in nonhuman primate (NHP) AIDS research grant funding over the past eight years. This growth in grant funding is accompanied by a high demand for Indian-origin specific pathogen free (SPF) rhesus macaques as the animal model for this research. YNPRC has continued to maintain a colony of SPF rhesus macaques under the parent grant (U42 OD011023) to provide these animals for HIV/AIDS research. This supplement application titled “Enhancements to the SPF Colony to Increase Production and Efficiency in Management” requests support for (1) the addition of novel “introduction enclosures” to select U42 supported compounds in the SPF colony that will ultimately increase production in the breeding colony and (2) the acquisition of a mobile procedure room and new capture tunnels that improve the efficiency of annual animal examinations and SPF testing of the colony. The goals of this supplement proposal will facilitate enhancements to the management and husbandry core in the parent U42 grant. The goals of the husbandry and management core are to leverage the resources provided by the U42 to maximize production of Indian-origin rhesus monkeys and facilitate allocation of these animals for NIH-funded HIV/AIDS research. This supplemental application will contribute to these goals with the following two specific aims: (1) to build additional introduction enclosures to improve the success of the introduction of multiple breeder males to female groups, thereby improving adult sex ratios and animal production and (2) to acquire a veterinary trailer and restraint capture tunnels to improve the efficiency of annual health surveys performed on the SPF colony at the Field Station Achieving these aims will help increase production and enhance management of the Yerkes U42 supported SPF breeding colony to ensure the program is sustainable, providing the necessary animals to support the HIV/AIDS research program using Indian-origin rhesus monkeys. The availability of this critical resource to scientists performing preclinical studies using the rhesus monkey model will have a positive, significant impact on the development of treatments to prevent or cure infection from HIV in people.