Medycyna Wet. 62 (1), 6-10, 2006
Litwińczuk A., Barłowska J., Król J., Litwińczuk Z.
Milk protein polymorphism as markers of production traits in dairy and meat cattle
The article presents a review of the results of a survey studying the relations between polymorphic forms of cows’ milk and its yield, chemical composition, physio-chemical traits as well as technological parameters and calf rearing results. The results of the research into the polymorphism of milk proteins have proven so reliable that genetic variants of milk proteins have been introduced more and more frequently as additional selection parameters in breeding surveys. This above all concerns b-lactoglobuline and k-casein genetic variants and their influence on protein content and the technological traits of milk, particularly in regard to the requirements of the dairy industry which prefers milk with better technological traits for cheese production. Most studies indicate a higher content of crude proteins as well as casein proteins in milk from cows having the BB b-Lg and BB k-Cn genotype. The BB k-Cn variant is also linked to milk production where there is a short coagulation time, higher compactness of clot and yield of fresh and mature cheese. The relations between forms of milk protein polymorphism and the results of calf rearing have not been unambiguously proved and are the subject of further research.
Keywords: dairy and meat cattle, milk proteins, genetic polymorphism