Date of Award
Doctor of Philosophy
Jerry L. Sell
Three experiments were conducted to test different dietary concentrations and different sources of vitamin E (VE) to reevaluate the dietary requirement of VE for young turkeys, and to determine whether an early high dose of VE given either by subcutaneous injection or added to the drinking water would improve the [alpha]-tocopherol ([alpha]TOC) status of poults. In Experiment 1, turkeys received 12 or 300 IU of VE/kg in the diet (dl-[alpha]-tocopheryl acetate (dl-[alpha]TACT)) or by subcutaneous injection (dl-[alpha]TOC), and were fed 5,000 or 15,000 IU of vitamin A/kg of diet. In Experiment 2, six of the treatments resulted from the factorial combination of two dietary sources (dl-[alpha]TACT or d-([alpha]TOC) and three concentrations (12, 80, or 150 IU/kg) of VE. The seventh treatment consisted of a single subcutaneous injection of 25 IU of d-[alpha]TOC at Day 1. In Experiment 3, treatments resulted from the addition to the diet of four equidistant increments of dl-[alpha]TACT (12, 46, 81, and 115 IU/kg of diet), or consisted of a single subcutaneous injection of 50 IU of d-[alpha]TOC at Day 1, or addition of 50 IU of d-[alpha]TOC/poult in the drinking water from Day 3 to Day 10. Increasing dietary concentrations of VE did not have a consistent effect on rate or efficiency of poult growth, but increased [alpha]TOC concentration in adipose tissue, adrenal glands, breast muscle (Pectoralis superficialis), bursa of Fabricius, small intestine, leg muscle (Biceps femoralis), liver, lung, pancreas, plasma, plasma fractions (VLDL, LDL, HDL), RBC, and uropygial gland. Increasing concentrations of dietary VE decreased RBC susceptibility to hemolysis from 1 to 21 d of age, but did not have an effect on plasma creatine kinase, plasma triglycerides, or liver TBARS. There was no consistent difference between sources of dietary VE (dl-[alpha]TACT, dl-[alpha]TOC, or d-[alpha]TOC) with respect to performance and tissue [alpha]TOC. Also, dietary vitamin A had little effect on performance or [alpha]TOC content of the tissues. Subcutaneous injection of dl-[alpha]TOC had variable effects on the parameters studied in Experiment 1, but injection of d-[alpha]TOC consistently increased [alpha]TOC in tissues and decreased the RBC susceptibility to hemolysis in Experiments 2 and 3. Supplementation of the drinking water with 50 IU of d-[alpha]TOC/poult from Day 3 to Day 10 temporarily increased [alpha]TOC in all tissues studied and decreased RBC hemolysis. There were high correlations between plasma [alpha]TOC and tissue [alpha]TOC, and liver [alpha]TOC and tissue [alpha]TOC after 7 d of age. As indicated by tissue [alpha]TOC and RBC susceptibility to hemolysis, concentrations between 81 and 115 IU of VE/kg of diet are needed to maintain an adequate health status of poults during the first 3 weeks after hatching.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Maria Fernanda Soto-Salanova
Soto-Salanova, Maria Fernanda, "Vitamin E in young turkeys: a reassessment of the requirement " (1995). Retrospective Theses and Dissertations. 10985.