Kappa-casein genotyping in tropical milking Criollo and its association to milk production and composition.

Caseins are abundant proteins in milk and found in four types (α, α, β, and κ). There is substantial variation in the allelic and genotypic frequencies of the κ-casein gene in different cattle breeds, although the tropical milking Criollo (TMC) has not yet been investigated. The aim was to determine the allelic and genotypic frequencies in the κ-casein gene for two alleles (A and B) in TMC and further investigate its association to milk production and composition.