In Peru criollo cattle play an important role in the lives of the communities of the high Andes; they are a source of protein and of labour; their milk is sold as raw material or used to produce cheese by traditional methods (quesillo or cachipa). Reports of molecular characterization of milk proteins in the Peruvian criollo cattle are scarce, and in the absence of selection and improvement programmes, the diversity of locally adapted criollo cattle is being lost, without greater advantage being taken of this animal genetic resource. The results of genetic characterization of kappa caseins (CSN3) and beta lactoglobulins (BLG) in four populations of criollo cattle from Andean communities in Peru are reported. Allelic frequencies were: CSN3A = 0.590, CSN3B = 0.410, BLGA = 0.400 and BLGB = 0.600.
