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|Title:||Trace Element Nutriture of the Chick as Affected by Eimeria Acervulina Infection|
|Author(s):||Southern, Lincoln Lee, Jr.|
|Department / Program:||Animal Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Agriculture, Animal Culture and Nutrition|
|Abstract:||Several experiments were conducted to investigate the trace mineral status of young chicks as affected by duodenal coccidiosis and by trace mineral intakes ranging from deficient to excess. The trace elements investigated were cobalt, iron, manganese, zinc and copper. Experimental coccidiosis was induced by inoculation with 2 x 10('5), 4 x 10('5) or 8 x 10('5) sporulated Eimeria acervulina oocysts on days 0, 3, 6, 9 and 12 of the 13- or 14-day assay periods.
The coccidial infection reduced rate and efficiency of weight gain regardless of trace element treatment. Severe growth depressions were obtained from feeding 250 mg/kg Co, 500 or 750 mg/kg Cu and 4000 mg/kg Zn. A Mn level of 5000 mg/kg or a Zn level of 2000 mg/kg depressed chick performance only lightly. Levels of Fe between 500 and 1500 mg/kg had no effect on rate or efficiency of weight gain. The coccidial infection exacerbated toxicities of Co, Fe, Mn and Cu as assessed by performance and by various hematological parameters. The infection also dramatically increased tissue deposition of these trace elements compared with that occurring in uninfected controls. Liver Cu concentration, for example, was quadrupled by the coccidial infection. Coccidiosis, however, had the opposite effect when excess levels of Zn were fed. The infection thus had an ameliorative effect on Zn toxicity and decreased tissue Zn levels.
An interaction between Zn and Cu was observed in this investigation. Excess Zn ingestion decreased liver Cu levels, but excess Cu had no effect on liver Zn levels. The effect of coccidiosis on increasing tissue Cu levels was diminished by excess dietary Zn.
Dietary requirements for Fe, Mn and Zn were estimated in healthy chicks to be 40, 15 and 13 mg/kg, respectively. The coccidial infection increased the chick's Fe requirement slightly, but only because of a reduced feed intake which resulted from the infection. Enhanced Mn utilization during coccidiosis resulted in a decreased Mn requirement in coccidiosis-infected chicks. The coccidial infection did not affect the chick's dietary requirement for Zn when a purified diet was used to assess the requirement. In a conventional corn-soybean meal diet, however, a response to supplemental Zn was observed in coccidiosis-infected chicks that was not observed in uninfected chicks. This suggests that coccidiosis impaired Zn utilization and precipitated Zn deficiency.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.
|Date Available in IDEALS:||2014-12-15|