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vi CHAPTER 1: GENERAL INTRODUCTION 1 Egg Nutrition 1 Rational for Nutrient Enrichment 2 Rational for Distribution Determination 5 Thesis Organization 5 References 6 CHAPTER 2: LITERATURE REVIEW 9 Vitamin E: Tocopherols and Tocotrienols 9 Absorption and Transport Vitamin E 12 Annatto Tocotrienols 14 Cholesterol Lowering 15 Cholesterol Quantification 18 Egg Formation 19 References 22 CHAPTER 3: SUPPLEMENTATION OF LAYING-HEN FEED WITH ANNATTO TOCOTRIENOLS AND IMPACT OF α-TOCOPHEROL ON TOCOTRIENOL TRANSFER TO EGG YOLK 27 Abstract 28 Introduction 29 Materials and Methods 30 Results and Discussion 36 Conclusions 46 References 48 Tables and Figures 5428 Introduction 29 Materials and Methods 30 Results and Discussion 36 Conclusions 46 References 48 Tables and Figures 54

The impact of supplementing laying-hen feed with annatto tocotrienols (T3s) and alpha-tocopherol on the distribution of various forms of vitamin E and cholesterol throughout the hen's body was evaluated. A total of 18 organs or tissues (skin, fat pad, liver and gall bladder, heart, oviduct, forming yolk, laid yolk, lungs, spleen, kidney, pancreas, gizzard, digestive tract, brain, thigh, breast, manure, and blood) were collected after 7 wk of feeding on diets enriched with various levels of alpha-tocopherol and annatto extract that contained gamma-T3 and delta-T3. Tissue weights, contents of lipid, alpha-tocopherol, gamma-T3, delta-T3, cholesterol, and fatty acid composition of extracted lipids from the collected organs and tissues were determined. Tissue weight and lipid content did not change significantly with feed supplementation treatments, except that the liver became heavier with increased levels of supplementation. Overall, the main organs that accumulated the supplemented vitamin E were fat pad, liver and gall bladder, oviduct, forming yolks, laid yolks, kidney, brain, thigh, and breast. Much of annatto gamma-T3 and delta-T3 (> 90%) was found in the manure, indicating poor uptake. In some tissues (brain and oviduct,) a significant increase in polyunsaturated fatty acids was seen with increased supplementation. Alpha-tocopherol impacted the transfer of gamma-T3 to forming and laid yolks, but did not impact delta-T3 transfer. No significant differences were found in most of the tissues in cholesterol, except a reduction in heart, based on tissue as-is. Blood samples showed large variations in individual hens with no significant differences in total and HDL cholesterol, or total triacylglycerols. Supplementing feed with annatto T3s and alpha-tocopherol showed that the vitamin E profile and distribution of the laying-hen body can be altered, but to different extents depending on tissue. The result of this research has significance in enhancing meat nutrient content.