Supplemental chromium for stressed and growing feeder calves.
The effects of supplemental chromium (Cr) from high-Cr yeast were investigated with steer calves fed corn silage diets. One hundred eight Charolais-crossed calves, weighing 245 kg after marketing and transport, were allotted to one of four treatments during the initial 28-d stress period: control, .4 ppm of Cr in the diet, long-acting injectable oxytetracycline (LAOTC), and Cr + LAOTC. Those fed Cr received 4 mg of Cr/d for the first 3 d sprinkled onto a small amount of hay over the silage. Chromium without LAOTC increased (P less than .05) ADG by 30% (.61 vs .79 kg/d) and ADG/DMI by 27% (.123 vs .156). Oxytetracycline alone increased (P less than .05) ADG by 30% and DMI by 15%. Chromium had no effect on morbidity. However, LAOTC tended (P less than .14) to reduce morbidity (26.0 vs 14.0%) after its administration. After d 28, steers were processed. Two weeks later, they were rerandomized within Cr groups to urea-corn vs soybean meal supplementation of corn silage during a 70-d growing period. Level of Cr was reduced to .2 ppm. Jugular blood was collected from eight steers on each treatment on two occasions. Chromium had no effect on ADG or ADG/DMI. However, Cr decreased (P less than .05) serum cortisol (75.0 vs 55.6 nmol/L). Furthermore, Cr increased (P less than .05) serum immunoglobulin M and total immunoglobulins in calves fed diets with soybean meal but had no effect in calves with urea-corn supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)
Chang
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Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Mowat
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D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D001798:Blood Proteins / Q000187:drug effects; D002417:Cattle / Q000097:blood / Q000254:growth & development / Q000276:immunology*; D002418:Cattle Diseases / Q000188:drug therapy*; D002857:Chromium / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004435:Eating / Q000187:drug effects; D006854:Hydrocortisone / Q000097:blood; D007136:Immunoglobulins / Q000097:blood; D008297:Male; D009017:Morbidity; D010118:Oxytetracycline / Q000008:administration & dosage / Q000627:therapeutic use; D012820:Silage; D013312:Stress, Physiological / Q000188:drug therapy / Q000662:veterinary*; D014508:Urea / Q000097:blood; D015430:Weight Gain / Q000187:drug effects; D003313:Zea mays
D001786:Blood Glucose; D001798:Blood Proteins; D007136:Immunoglobulins; D002857:Chromium; D014508:Urea; D006854:Hydrocortisone; D010118:Oxytetracycline