THE EFFECT OF BREED, β-LACTOGLOBULIN VARIANTS AND SOMATIC CELL COUNT ON YIELD, CHEMICAL COMPONENTS AND WHEY PROTEIN COMPOSITION IN MILK OF NON-DAIRY SHEEP. - Rozbicka-Wieczorek, A.; Radzik-Rant, A.; Rant, W.; Puppel, K. (JAPS: Journal of Animal & Plant Sciences, 2015)