Effect of level of supplemental chromium on performance, serum constituents, and immune status of stressed feeder calves.
The effects of level of supplemental Cr from high-Cr yeast on performance, blood chemistry profile, morbidity, and immune status were investigated using 84 Charolais-crossed steer calves in a completely randomized design. Calves of 236-kg average weight, after transportation from Saskatchewan to Ontario, were randomly assigned to four treatments; 0, .2, .5, and 1 ppm of supplemental Cr, incorporated into a corn-silage diet. Blood was collected via jugular venipuncture at d 0, 7, 14, 21, and 28 and analyzed for metabolites, minerals, immunoglobulins, hematocrit (Hct), and leucocyte counts. Hemagglutinating antibody titers to human red blood cells (HRBC) were quantified after immunizations on d 0 and 14. Contact sensitivity after sensitization and challenge with dinitrochlorobenzene was also measured. A 27% increase (P < .05) in ADG was observed at d 30 for calves that were fed .2 and 1 ppm of supplemental Cr. Dry matter intake also increased (P < .05) for the .2- and 1-ppm Cr treatments. A linear decrease (P < .05) in serum cortisol with increasing Cr level was observed at d 28. Chromium supplementation decreased (P < .05) morbidity, as well as rectal temperatures at d 2 and 5. Peak primary antibody titers to HRBC (P < .05) and immunoglobulin G1 concentrations (P = .06) at d 14 were higher for steers that received the Cr supplementation. However, Cr treatment had no effect on expression of contact sensitivity. Chromium supplementation increased (P < .05) Hct on d 14 and 21 and serum Ca and Mg on d 7.(ABSTRACT TRUNCATED AT 250 WORDS)
Moonsie-Shageer
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Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Mowat
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D000821:Animal Feed; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002118:Calcium / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000276:immunology / Q000517:prevention & control*; D002857:Chromium / Q000008:administration & dosage / Q000627:therapeutic use*; D004435:Eating / Q000187:drug effects; D006400:Hematocrit / Q000662:veterinary; D006854:Hydrocortisone / Q000097:blood; D008274:Magnesium / Q000097:blood; D008297:Male; D009017:Morbidity; D011897:Random Allocation; D012709:Serum Albumin / Q000187:drug effects; D013312:Stress, Physiological / Q000097:blood / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D014186:Transportation; D015430:Weight Gain / Q000187:drug effects
D012709:Serum Albumin; D002857:Chromium; D008274:Magnesium; D002118:Calcium; D006854:Hydrocortisone