A Copper Deficiency in Neonatal Pigs Induced by a High Zinc Maternal Diet

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Abstract
Because high levels of dietary zinc are known to reduce copper body stores, the objective was to determine if a high zinc maternal diet could induce a copper deficiency in the newborn pig fed a dried skim milk-glucose-starch diet unsupplemented with copper. The offspring of gilts, which were fed 5000 ppm of zinc, were allowed to nurse until 3 to 5 days of age when they were weaned and placed in individual stainless-steel pens. The dietary treatments were 0, 5 and 10 ppm added copper from copper sulfate. After 14 days, pigs receiving the 0-ppm copper diet weighed significantly less (P < 0.05) and had reduced hemoglobin, hematocrit and serum copper concentrations and no detectable ceruloplasmin activity. After 5 weeks, the pigs were killed, and tissues were collected. The unsupplemented group had 16.4% of the aortic lysyl oxidase activity of the 5-ppm group. Cytochrome c oxidase activity in the heart and liver, and copper stores in the heart, liver, pancreas and kidney were depressed (P < 0.05) in unsupplemented pigs compared to those receiving 5 ppm copper. These data demonstrate that it is possible to produce quickly a markedly copper-deficient pig, by using the offspring of sows fed 5000 ppm zinc, and support previous conclusions that the dietary copper requirement of the baby pig is about 5 ppm.