Supplementation of Broiler Diets with all-rac-ケ- or a Mixture of Natural Source RRR-ケ-, コ-, ゴ-Tocopheryl Acetate.: 1. Effect on Vitamin E Status of Broilers In Vivo and at Slaughter

Abstract

A total of 300 female broiler chickens were reared from day-old to 10 d of age on the same starter diet. Then they were divided into five groups, receiving a control diet (Group 1) relatively rich in fat (14.3%) and unsaturated fatty acids (87.6%) and standardized with respect to vitamins and minerals, supplemented with 100 mg (Group 2) and 500 mg (Group 4) of RRR-ケ-, コ-, ゴ-tocopheryl acetate/kg feed (40.6% ケ-, 41.1% コ-, 18.3% ゴ-) or 100 mg (Group 3) and 500 mg (Group 5) all-rac-ケ-tocopheryl acetate/kg feed until slaughter at 6 wk of age.No differences between the supplemented groups were observed with respect to weight gain, feed consumption, packed cell volume (PCV), plasma enzyme activities of creatine kinase (CK) and glutathione peroxidase (GSH-Px), fatty acid composition, and enzyme activities of citrate synthase (CS), and total lactate dehydrogenase (LDH), and 3-OH-acyl-coenzyme A-dehydrogenase (HAD) of breast (Pectoralis major) and thigh (Gastrocnemius interna) muscle. Increasing levels of ケ-, コ-, and ゴ-tocopherol were found in blood plasma with increasing dietary levels of these tocopherols. Only ケ-tocopherol was detectable in skeletal muscle and in higher concentrations in thigh than in breast muscle. Hemolysis in vitro and plasma activity of aspartate aminotransferase (ASAT) were lower (P < .01) in Groups 2 and 4 than in Groups 3 and 5. Interactions were observed between dietary type and concentration of tocopherols for plasma CK, GSH-Px, Na+, and K+. No measurable excretion of ethane and pentane was observed in any of the groups. The findings indicate that the oxidative stress in the live animals was minimal. The mixture of natural source RRR-ケ-, コ-, ゴ-tocopherols was as efficient in protecting the live chickens as the all-rac-ケ-tocopheryl acetate, when provided on a weight basis as judged from the chosen in vivo parameters of vitamin E status.