Priming of AA broiler chickens and rabbits with T. gondii YFP (TgYFP) elicited antigen specific antibody responses. A, YFP specific IgG in chicken sera (1: 25) 10 days after immunization by s.c. injection of 5 × 106 transgenic (TgYFP), wild type (WT) T. gondii tachyzoites or complete cytomix buffer (CCB). B, YFP specific IgG (1:25) 10 days after immunization by s.c. or i.m. injection. C, Serum YFP specific antibody titers in chickens 10 days after a s.c. injection of transgenic T. gondii tachyzoites (TgYFP) or i.m. injection of recombinant YFP (rYFP) protein expressed in E. coli. D, Kinetics of serum antibodies to YFP and tachyzoite antigens in rabbits immunized with the transgenic T. gondii. * P < 0.05, ** P < 0.01.