8Paterson J E.Macpherson A.A comparison of serum VitaminB12 and serum methylnlonic acid diagnostic measures of cobalt status in cattle[J].The Veterinary Record,1990(7):329-332
9Mburu-JN,Badamana-MS,Kamau-JMZ.Faecal and urinary losses of nitrogen in cobalt-deficient small East African goats[J].Indian Journal of Animal Science,1994,64:11,1 264-1 267
10NRC.Nutrient requirements of dairy cattle Seventh revised edition,2001