Nutritional evaluation of a copper-methionine complex for chicks.
Three chick experiments were conducted to evaluate a new Cu complex product, Cu-Met. Relative bioavailability of Cu was assessed with two bioassay systems, one employing bile Cu concentration as the criterion at Cu-deficient levels and another employing liver Cu concentration at Cu-excess levels. Relative bioavailability of Met was assessed separately. Common-intercept multiple linear regression (slope-ratio) of bile Cu concentration or liver Cu concentration regressed on supplemental Cu intake was used to assess Cu bioavailability relative to the standard, analytical-grade CuSO4.5H2O, which was set at 100%. In addition, Cu-Lys and CuCl (compounds previously evaluated by bile Cu concentration) were evaluated by the liver Cu accumulation method. Relative bioavailability of Cu in Cu-Met was estimated as 96% by the bile Cu assay and 88% by the liver Cu assay, which were not different (P > .05) from 100%. The liver Cu assay estimated that relative Cu bioavailabilities in Cu-Lys and CuCl of 114 and 145% (P < .05), respectively. These values were very close to those previously estimated by the bile Cu assay. Relative Met bioavailability of Cu-Met was 100% of the standard, i.e., feed-grade DL-Met.
Aoyagi
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Department of Animal Sciences, University of Illinois, Urbana 61801.
Baker
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D000821:Animal Feed; D000818:Animals; D002645:Chickens; D003300:Copper / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004435:Eating; D005260:Female; D005527:Food, Fortified; D008297:Male; D008715:Methionine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009753:Nutritive Value; D015430:Weight Gain
D003300:Copper; D008715:Methionine