5Puchala R, Sahlu Davis T. Effect of zinc - methionine on performance of Angra goats. Journal of Animal Science, 1996( 1 ) : 266.
6Spears J W, Schoenherr W D. Efficacy of iron methionine as asource of iron for nursing pigs. J. Anim. Sci., 1992,70(1) :59.
7Spears J W, Kegley E B. Effect of zinc source(zinc oxide vs zinc proteinate) and level on performance, carcass characteristics, and immune response of growing and finishing steers. J. Anita. Sci., 2002 (80) :2747 - 2752.
8Spear J W. Effect of zinc and manganese, methionine on performance of beef cows and calves. Journal of Animal Sciences, 1991,69( 1 ) :59.
