BENEFICIAL-EFFECTS OF CHROMIUM ON GLUCOSE AND LIPID VARIABLES IN CONTROL AND SOMATOTROPIN-TREATED PIGS ARE ASSOCIATED WITH INCREASED TISSUECHROMIUM AND ALTERED TISSUE COPPER, IRON, AND ZINC

Chromium (Cr) and somatotropin have been shown to increase lean body m ass in pigs but by independent mechanisms. Somatotropin and Cr also af fect blood glucose, lipids, and tissue trace metal concentrations. Twe nty-four castrated male pigs were divided into four groups: 1) control basal diet; 2) basal diet + 300 mu g of Cr/kg of diet as Cr picolinat e; 3) basal diet + pituitary porcine somatotropin (ppST; 100 mu g/kg l ive weight injected daily); and 4) basal diet + Cr + ppST. Pigs were f ed the diets from 30 to 60 kg body weight and then killed. Supplementa l Cr led to increased total Cr in kidney (1.1 vs 2.3 mu g) and liver ( 5.9 vs 8.8 mu g) but not in the heart independent of ppST treatment. C hromium concentrations in longissimus muscle were less than 1.5 ng/g i n all samples, and any increases due to supplemental Cr were not detec ted. Somatotropin treatment led to decreased hepatic Cr, Cu, Fe, and Z n concentrations and increased total renal Cu, Fe, and Zn. These data demonstrate that supplemental Cr causes increased tissue Cr in the liv er and kidney but not in the heart or muscle in control and somatotrop in treated pigs. Somatotropin treatment caused decreased kidney and Li ver Cr concentrations that were offset by increased tissue weights. So matotropin effects on tissue Cr, Cu, Zn, and Fe were variable and diff icult to evaluate due in part to growth hormone-induced changes in org an weights.