Laying hens of the Isa Brown lineage, 25 weeks of age, were used for immunization protocols. Hens were kept in individual cages and received commercial rations and water ad libitum. C57BL/6 mice, 6-8 weeks old, were infected with T. gondii ME-49 strain to obtain parasite positive brain tissue sections [42] and immunized with STAg to obtain polyclonal IgG antibodies anti-T. gondii [43] . All animal procedures were approved by the institutional ethics committee in animal experimentation (Comissão de É tica no Uso de Animais da Universidade Federal de Uberlândia -Protocol No. 107/11), and were performed based on the Ethical Principles in Animal Research adopted by the Brazilian College of Animal Experimentation and instructions disposed in the 2000 Report of the AVMA Panel on Euthanasia [44] .