EFFICACY OF DIETARY AND INJECTED VITAMIN-E FOR POULTS

An experiment was conducted to compare the efficacy of two dietary sou rces and an injectable form of vitamin E (VE) to improve the VE status of poults. Six of the treatments consisted of a factorial arrangement of three concentrations and two sources of dietary VE. Turkeys in the se treatments received 12, 80, or 150 IU of either dl-alpha-tocopheryl acetate or d-alpha-tocopherol (d-alpha-TOC)/kg of diet. The seventh t reatment consisted of a single subcutaneous injection of d-alpha-TOC a t 1 d of age. Poults in this treatment were subcutaneously injected in the dorsal area of the neck with 25 IU of d-alpha-TOC, this amount be ing approximately equivalent to the amount poults would consume if the ir diet was supplemented with 150 IU of VE/kg during their Ist wk of l ife. Concentration, source, or route of VE administration did not affe ct growth parameters, plasma creatine kinase, plasma triglycerides, or liver lipid peroxidation as measured by the thiobarbituric acid react ive substances assay (TEARS). Plasma, red blood cells (REC), and liver alpha-TOC decreased from hatching to 14 d of age in poults fed either source of VE. The use of 80 or 150 IU of dietary VE (either source) r educed (P < 0.05) the extent of depletion of alpha-TOC at all ages and also reduced the susceptibility of RBC to hemolysis. There was no eff ect of source of dietary VE on concentration of alpha-TOC in plasma, R BC, or liver, or on RBC hemolysis. Subcutaneous injection of 25 IU of d-alpha-TOC at Day 1 increased (P < 0.05) alpha-TOC concentration unti l 7 d of age. Also, d-alpha-TOC injection reduced (P < 0.05) RBC susce ptibility to hemolysis through 21 d of age. Data showed that one singl e subcutaneous injection of 25 IU of d-alpha-TOC at 1 d of age was as effective as 80 IU or more of dietary VE through 21 d to improve the a lpha-TOC status of poults.