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

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%).     

Occurrence of β-lactam-resistant Staphylococcus aureus in milk from primiparous dairy cows in the northeastern region of Brazil

Tropical Animal Health and Production - The objective of the current study was to isolate and identify Staphylococcus (S.) aureus strains resistant to beta-lactam antibiotics from primiparous...