Degree Type


Date of Award


Degree Name

Master of Science


Food Science and Human Nutrition

First Advisor

Tong Wang


Laying-hens efficiently transfer nutrients from their feed to the resulting eggs, and nutrients from feed are distributed in many organs and tissues for various uses. Annatto is the only known source of tocotrienols (T3s) (gamma-T3 ~10% and delta-T3 ~90%) without alpha-tocopherol present. The T3s have many health benefits including lowering cholesterol. The objective of this research was to study the effect of alpha-tocopherol on the transfer of T3s to eggs and various organs and tissues in the body of the laying-hen. To do so, laying-hens were fed treatment diets for 7 weeks supplemented with annatto T3s in the presence and absence of alpha-tocopherol. The diet regimens were a control diet with not supplementation and three diets with 2000 ppm annatto extract and added alpha-tocopherol at 200 and 1000 ppm.

No significant differences were found in egg production or egg yolk properties (moisture content of moisture, lipid, phospholipids, fatty acids, or cholesterol). Significant differences (p<0.05) were found in feed intake, yolk viscosity, sensory yolk flavor and color, and transfer efficiency of tocopherols and T3s to the egg yolks.

Alpha-tocopherol was transferred more efficiently (21.19-49.17%) than gamma-T3 (0.50-0.96%) or delta-T3 (0.74-0.93%) to the egg yolks. Addition of 1000 ppm of alpha-tocopherol decreased the transfer of gamma-T3 (by 23.76%) but it did not impact the transfer of delta-T3 to the egg yolk. The addition of annatto T3s did not significantly impact the cholesterol content of the laid eggs.

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 weeks of feeding the diets. Tissue weights, moisture content (except for manure), lipid, alpha-tocopherol, gamma-T3, delta-T3, cholesterol, and fatty acid composition of extracted lipids in the collected organs and tissues (except for blood) were determined.

Tissue weights, moisture content, and lipid content did not change significantly with feed supplementation across treatments, except that the liver became heavier with increased supplementation. Minimal changes were found in the fatty acid composition, except in the fat pad, oviduct, brain, and manure.

Overall, the main organs that accumulated the supplemented forms of vitamin E were fat pad, liver and gall bladder, oviduct, forming yolks, laid yolks, kidney, brain, thigh, and breast. Much of annatto supplement (gamma-T3 and delta-T3) was detected in the manure (>90%), indicating that most was excreted and not used by the hen. 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 the forming and laid yolks, but did not impact delta-T3 transfer. No significant differences were found in the cholesterol in the liver, kidney, laid yolks, breast meat, oviduct, or thigh meat, except for cholesterol reduction in the heart based on as-is tissue weight. Blood samples showed large variation among individual hens with no significant differences in total cholesterol, HDL, or total triacylglycerols.

The results indicate that supplementing hen-laying feed with annatto T3s and alpha-tocopherol can alter the vitamin E profile and its distribution among the laid eggs and laying-hen organ and tissues (especially in the liver and egg yolks). Therefore it is possible to enhance the nutritional profile of the egg to further benefit the consumers and to increase oxidative stability of various organs and tissues.


Copyright Owner

Hannah Elisabeth Hansen



File Format


File Size

114 pages