6Hering stad B,Klemetsdal G,Ruane J. Clinical mastitis in Norwegian cattle:frequency,‰ariance components,and genetic correlation with protein yield[J].Journal of Dairy Science,1999,(06):1325-1330.
7Urech,Puhan,Schallibaum. Changes in milk fraction as affected by sub-clinical mastitis[J].Joumal of Dairy Science,1999,(11):2402-2411.