Summary and Implications
The data demonstrate that cows with the genotypes κ- casein BB and β-lactoglobulin BB produce milk with a protein composition that is favorable for increased cheese yield. For proportions of αS1-casein, κ-casein, and β-lactoglobulin in total milk protein, κ-casein and β-lactoglobulin genotypes explained more than 50 and 25% of the heritability and repeatability estimates, respectively, and more than 14% of the phenotypic variance. Diet had only a minimal effect on milk protein composition. In conclusion, increasing cheese yield through modification of milk protein composition can be achieved most rapidly by selection for cows with κ-casein BB and β-lactoglobulin BB genotypes.
Iowa State University
Bobe, Gerd; Freeman, A.E. Gene; Lindberg, Gary L.; and Beitz, Donald C.
"Milk Protein Genotypes Explain Variation of Milk Protein Composition,"
Animal Industry Report:
AS 650, ASL R1901.
Available at: http://lib.dr.iastate.edu/ans_air/vol650/iss1/60