Effects of source on copper uptake by swine.

Four catheterized crossbred (Y x H) barrows were used in a 4 x 4 latin square arrangement of treatments in a completely randomized block design, to determine the effect of source on copper uptake as determined by serum Cu concentration changes over a 7.5-hr sampling period. Dietary treatments were: (A) basal with no added Cu, (B) basal + 5.2 mg Cu (from CuSO4)/kg of diet, (C) basal + 5.2 mg Cu (EDTA chelated Cu)/kg of diet, and (D) basal + 5.2 mg Cu (from CuSO4) + 34.1 mg ethylene diamine tetra acetic acid (EDTA)/kilogram of diet. Animals were placed on the semi-purified basal diet for 5 days, fasted for 1 day and then given their dietary treatment. Following consumption of the dietary treatment, blood samples were collected from each animal at 15-min intervals for 3.0 hr and at 1.5-hr intervals over the remaining 4.5 hr of a 7.5-hr sampling period. The samples were collected via jugular catheters and during the 4-week trial each animal was exposed to all dietary treatments. Serum Cu concentration was not significantly (P< .05) affected by dietary treatment. However serum Cu concentrations did change significantly (P< .05) during the 7.5-hr sampling period. A significant 3Department of Animal Science. Acknowledgement is made to John Welch and Larry MeMullen for their assistance with the conduct of the experiment and development of certain laboratory procedures. (P< .01) animal x sampling time interaction was also observed. The results indicate that prechelated Cu or dietary additions of EDTA had little influence on the efficiency of Cu uptake by swine. Sampling time following consumption of a diet was important as evident from the reflected changes in serum Cu concentration.