Detection of B kappa-casein variant (CSN3*B) in Burlina dairy cattle by PCR-TTGE

The aim of this study was to develop and optimize a PCR-TTGE method for the detection of B κ-casein variant (CSN3*B), which is known to play a major role in cheese technology. The effects of the different κ-casein alleles on the quality and the quantity of cow’s milk have been widely reported and the availability of accurate and reliable protocols for the identification of the most common alleles is of great interest in breeding projects. In the present study a new genomic DNA extraction method from milk samples and a PCR-TTGE protocol to quickly identify A and B κ-casein allelic variants were developed. The DNA extraction method was fast and suitable for DNA amplification, while TTGE proved to be a powerful technique for discrimination of A and B alleles. This method was applied to 197 milk samples derived from Burlina, an Italian dairy cattle breed. CSN3*B allele frequency as detected by PCR-TTGE was 0.368. The development of this PCR-TTGE protocol could be used for future breeding programs to improve milk coagulation ability traits.