7Wray N. Consequences of selection in closed population with particular regerence to closed nucleus herds of pigs.Edinburgh: University of Edinburgh. 1989.
8Pulina G,Nudda A,Bauacone G,et al.Effects of nutrition on the contents of fat,protein,somatic cells,aromatic compounds,and undesirable substances in sheepmilk[J].Sci Direct,2006,131(3-4):255-291.
9Rekik B,Ajili N,Belhani H,et al.Effect of somatic cell count on milk and protein yields and female fertility in Tunisian Holstein dairy cows[J].Dairy Sci,1998,81:1285-1290.