Effects of ascorbic acid on stress and disease in chickens.
White leghorn chickens were given feed containing 100 mg of ascorbic acid (AA)/kg. One day later, treated chickens and a similar group of unmedicated control chickens were chilled for 1 hour at 6 C, exposed to an unusual sound, fasted, or subjected to rough handling. Heterophil:lymphocyte (H:L) ratios were determined one day later. The AA-treated birds had significantly lower H:L ratios than untreated controls. Chickens that received a diet containing AA had lower H:L ratios than controls (0.86 vs. 1.65) following administration of adrenocorticotropic hormone. Chickens fed a diet containing AA showed increased resistance to a combined Newcastle disease virus-Mycoplasma gallisepticum infection and to a secondary Escherichia coli infection, as well as to a primary E. coli challenge infection. The effects of AA and an antibacterial drug (furaltadone) were additive. In all experiments, the optimum dose of AA was 100 mg/kg of feed. There was a negative correlation between AA level in the diet and feed efficiency.
Gross
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Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg 24061.
D000818:Animals; D001205:Ascorbic Acid / Q000627:therapeutic use*; D002645:Chickens / Q000276:immunology* / Q000382:microbiology; D003080:Cold Temperature; D004927:Escherichia coli Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D005527:Food, Fortified; D009175:Mycoplasma Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D011201:Poultry Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D013312:Stress, Physiological / Q000276:immunology / Q000662:veterinary*; D015430:Weight Gain
D001205:Ascorbic Acid