SPARING EFFECTS OF COBALT AND NICKEL ON ZINC NUTRITION IN PIGS

Three experiments were conducted to determine whether cobalt (Co) or nickel (Ni) could prevent zinc (Zn) deficiency signs in pigs fed a high calcium (Ca) corn-soybean diet. The basal diet contained 1.3% Ca, .93% phytic acid and means of 34 to 48 ppm Zn. After weanling, pigs in experiment I were fed the basal diet for 9 weeks, and was found that 50 ppm Co or Ni for 5 weeks increased average daily weight gain (ADG) and reversed skin lesions toward normal. These effects were similar to those of 100 ppm supplemental Zn. The Zn content and alkaline phosphatase activity of serum from pigs supplemented with Co or Ni were higher at 2 weeks and 4 weeks (P<.05) than those of the basal group. Zn content of bone, liver and kidney, and alkaline phosphatase activity in bone were increase after 5 weeks of supplementation with Co or Ni. In experiments 2 and 3, addition of 54 ppm and 27 ppm of either Co or Ni increased (P<.05) ADG and decreased incidence of skin lesions except in one group supplemented with 27 ppm Ni. Supplemental Co or Ni increased Zn in serum and alkaline phosphatase activity in serum and bone in both experiments. Over all experiments, supplemental Co or Ni decreased Zn deficiency signs in the following order of effectiveness: 54 ppm Co, 54 ppm Ni, 27 ppm Co and 27 ppm Ni. The alleviation of signs of Zn deficiency by Co or Ni may have been the result of increased availability of dietary Zn.