The aim of this study was to examine the sensitisation capacity of goat milk (GM) and cow milk (CM) by the oral or the parenteral route, and thus determine whether the serologic responses developed are different, identify the proteins targeted by the antibodies thus formed, and determine whether these antibodies depend on the immunisation route employed. Enzyme-linked immunosorbent assay was used to determine the specific antibodies of the isotypes IgG1 and IgG(Fc) developed against GM and CM. The sera from the animals immunised parenterally developed a stronger serologic response than did those immunised by the oral route. When CM was used as the immunising agent, the specific isotopic response was stronger than that obtained with GM. There were no differences in the antigen profile revealed by the sera of the animals immunised by the oral or parenteral routes. A marked degree of cross-reactivity between the two types of milk was found. This study was financially supported by the Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía, Spain (Project: C03-045). Peer reviewed