Core B Summary The Large Animal Core provides the facilities, management and technical expertise needed to supply miniature swine and baboons and tissue samples for all projects of the proposed program as well as expert veterinary care, immunological reagents, and microbiologic diagnostic assays and support. Clinical samples are distributed to maximize utilization of each animal for studies of clinically relevant regimens for xenotransplantation. The success of each component of this program is dependent on the quality, predictability, and accessibility of the animals, microbiologic support, and antibodies provided by this Core. Animal care is reviewed weekly at meetings of the principal investigators and the veterinary staff. The Aims of the Large Animal Core include: Aim 1: Purchase and maintenance of non-human primates; Aim 2: Oversee and coordinate the production and maintenance of an SPF facility of MHC inbred miniature swine including genetically engineered knock-out and transgenic swine, derived by Caesarian section when assurance of pCMV-free status is required for use as xenograft donors; Aim 3: Carry out genetic and phenotypic screening, quality control, and tracking of miniature swine in Aim 2; Aim 4: In conjunction with Core C, develop and maintain new genetically engineered swine designed to facilitate tolerance induction; Aim 5: Develop and utilize protocols to synchronize estrus and time of breeding, in order to increase farrowing percentage and better control and predict production levels; Aim 6: Provide diagnostic and management support related to infectious diseases, including prophylaxis and care paradigms for the care of immunosuppressed xenograft recipients and support of ongoing studies by routine assessment of swine and baboon recipients for pCMV, bCMV, PERV and other pathogens.