Genetic polymorphism of β-lactoglobulin and κ-casein of cattle breeds in Croatia

Učinkovita proizvodnja mlijeka uvažava interese proizvođača, preradbene industrije, potrebe potrošača i dobrobiti životinje. Razvoj novih metoda direktne analize gena odgovornih za polimorfizam bjelančevina mlijeka daje nove alate u podizanju profitabilnosti proizvodnje mlijeka i mliječnih proizvoda kroz ugradnju pasminskog genetskog profila u gojidbeni program. Radi nužnosti determinacije genetskog profila pasmina goveda u Hrvatskoj, koristeći nove analitičke metode određen je udio dominantnih alelnih polimorfnih varijanti beta-laktoglobulina (β-Lg) i kapa-kazeina (κ-CN). Udio alelne B varijante beta-laktoglobulina dominantan je u svim istraženim pasminama goveda (>52,9 %). Alelna A varijanta kapa kazeina je dominantna u selekcioniranim pasminama goveda (60,7-76,4 %), dok je udio B varijante kapa-kazeina značajno zastupljeniji u izvornim pasminama goveda (48,2-84,1 %). Spoznaje o genetskom profilu pasmina obzirom na istražene polimorfne varijante bjelančevina mlijeka su korisne u daljnjoj uzgojnoj izgradnji i gospodarskoj afirmaciji, posebice izvornih pasmina goveda.Profitable milk production respects the interests of producers, processing industries, consumer requirements and welfare of animals. Development of new methods of direct gene analysis responsible for milk proteins polymorphism provide new tools to raise the profitability of milk production and dairy products through implementation of breed genetic profile in breeding program. Because of necessity to determinate genetic profiles of cattle breeds in Croatia using new analytical methods, the ratio of dominant allelic polymorphic variants of beta-lactoglobulin (β-Lg) and kappa-casein (κ-CN) is defined. The share of beta-lactoglobulin B variant is dominant in all investigated cattle breeds (>52.9 %). Kappa- casein allelic variant A is dominant in selected cattle breeds (60.7-76.4 %), while the share of B variant is significantly more presented in autochthonous cattle breeds (48.2-84.1 %). Knowledge about genetic profile of breeds due to studied polymorphic variants of milk proteins is useful in further breeding development and economic reaffirmation of cattle breeds, especially autochthonous ones