Breast muscle FeAILP was not affected by increasing dietary M/S or Vitamin E
(Table 8). The low fat content in the breast muscle could be responsible for the low
FeAILP observed, which made the M/S or Vitamin E effect less pronounced.
Thigh muscle TBAvalue decreased (P < 0:01) by increasing dietary M/S or Vitamin E.
The antioxidative property of Vitamin E in breast and thigh muscles of chickens is well
documented (Jensen et al., 1995; Cherian et al., 1996). Elevated Vitamin E level in poultry
feeds increases tissue concentrations, and the improved stability of membranal structures
may be expected to increase the oxidative stability of the tissues. Current results support
this observation. Increasing dietary Vitamin E, increased liver a-tocopherol content
(Table 7) and, thus, increased the oxidative stability of the liver. Increasing dietary
Vitamin E, on the other hand, did not increase heart and breast muscle a-tocopherol
contents (Table 7) and, thus, did not increase the oxidative stability of the heart and breast
muscle. The magnitude of the antioxidative property of Vitamin E was relatively low
compared to that of M/S probably because only about 21 mg Vitamin E was contained kg1
of the diets. Marusich et al. (1975) reported that 40–60 mg a-tocopherol kg1 of the diet
was needed to protect the raw chicken muscles during frozen storage.