EFFECT OF CHROMIUM TRIPICOLINATE ON GROWTH, GLUCOSE-TOLERANCE, INSULIN SENSITIVITY, PLASMA METABOLITES, AND GROWTH-HORMONE IN PIGS

Two experiments were conducted to evaluate the effect of Cr as Cr trip icolinate (CrPic) on growth, glucose tolerance, insulin sensitivity, p lasma metabolites, and growth hormone (GH) in pigs. Pigs were fed a co ntrol diet or a diet supplemented with 200 mu g of Cr/kg of diet as Cr Pic. Thirty (15 per diet, initial BW was 21.3 kg) and 24 (12 per diet, initial BW was 24.9 kg) crossbred barrows were used in Exp. 1 and 2, respectively. The diets were formulated to provide 120% of the lysine requirement for 20- to 50-kg pigs. A glucose tolerance test (IVGTT; 50 0 mg of glucose/kg BW) and an insulin challenge test (IVICT; .1 IU of porcine insulin/kg BW) were conducted. In addition, during Exp. 1, a G H-releasing hormone (GHRH) challenge was conducted. All data were pool ed across experiments, except where noted. Average daily gain, ADFI, g ain/feed, and fasting (15 to 18 h) plasma glucose and total protein co ncentrations were not affected (P > .10) by dietary treatment. Fasting plasma cholesterol (P < .05) was increased and NEFA (Exp. 2 only, P < .02), urea N (P < .07), and insulin (P < .10) concentrations were dec reased in pigs fed CrPic. During the IVGTT and IVICT, glucose disappea rance rate (k, percentage/minute) was increased (P < .04) and glucose half-life (t(1/2), minutes) was decreased (P < .04) in pigs fed CrPic; however, insulin kinetics were not altered (P > .10). During the GHRH challenge, pigs fed CrPic had decreased(P < .09) area under the respo nse curve for GH. There was no effect (P > .10) of CrPic on GH concent rations prior to administration of GHRH. The results of this study ind icate that dietary Cr as CrPic increases glucose k and decreases gluco se t(1/2) in growing pigs.