Protein heterogeneity of bovine β-casein in Danish dairy breeds and association of rare β-casein F with milk coagulation properties

ABSTRACT

A proteomic approach was applied to characterize genetic variation and relative protein content of β-casein (β-CN) in milk from two minor native dairy breeds in Denmark; Red Danish 1970 and Jutland cows in comparison to the major dairy breeds; Danish Holstein and Danish Jersey. Genetic β-CN variants were related to the relative concentration of β-CN. Furthermore, a very high frequency of variant F in the native breeds was found. This was remarkable as this variant is only found in a very low frequency in the major Danish breeds. Novel associations were found between β-CN variant F and milk coagulation properties in the native breeds, which is an important finding for understanding the genetic background for non- and poor coagulating milk and potential exploitation of β-CN variants in selective breeding programs. Furthermore, in Red Danish 1970 a very high prevalence of non-coagulating milk was found (18%).

KEYWORDS:

• Genetic polymorphism
• mass spectrometry
• liquid chromatography
• sequencing
• native breeds

Acknowledgements

The authors thank the farmers providing milk for the projects for the collaboration.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors wish to thank The Danish Agrifish Agency (Copenhagen K, Denmark, [grant number 14-32640-000021]) and Aarhus University (Aarhus, Denmark) for financial support.