Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Food, Nutrition and Packaging Sciences

Committee Chair/Advisor

Northcutt, Julie K

Committee Member

Dawson , Paul

Committee Member

Haley-Zitin , Vivian


In the last few decades equol, a metabolite of the isoflavone daidzein, has become the target of various animal and human studies. Coined the key to health benefits associated with soy foods, equol formation been implicated in the healthy profiles associated with Asian populations. As a metabolite of daidzein, equol must be synthesized from its precursor by intestinal bacteria; however, clinical and epidemiological studies indicate that only about a third of the general human population possess the microflora necessary to metabolize equol. Research indicates that by supplementing laying hens with soybean meal, equol deposition into table eggs can be stimulated, thereby creating a functional direct source of this estrogenic compound, independent of gut microflora. Though equol enhanced eggs may be created through soy supplementation, isoflavones are bioactive and have various physiological effects when consumed. Thus, the purpose of this research project was to examine the impact of various levels of soy supplementation (soy-free-SF, standard soy-SS, soy enhanced-SE) on bone characteristics and egg quality in young battery-cage (BC) and free-range (FR) laying hens. The research was conducted concurrently with a study that determined the level and rate of equol deposition into table eggs from the same flock.
Findings of the current research showed that SE combined with physical activity had a significant impact on bone health as evidenced by increased femoral weight (P=0.005), length (P=0.0066), bone strength (P=0.016) and compression energy (P=0.013). Additionally, higher levels of phosphorous (P=0.012), magnesium (P Overall, the effects associated with dietary isoflavones via soy supplementation beneficially altered various quality characteristics that affect both animal welfare and poultry farmers. Decreased bone fractures associated with avian osteoporosis could improve animal welfare as well as curb economical losses associated with layer mortality. Furthermore, stronger eggshells could reduce the percentage of cracked and downgraded eggs.

Included in

Food Science Commons



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