Theses and Dissertations

Advisor

Yamamoto, Fernando Yugo

Committee Member

Allen, Peter J.

Committee Member

Rossi, Waldemar, Jr.

Date of Degree

8-7-2025

Original embargo terms

Immediate Worldwide Access

Document Type

Graduate Thesis - Open Access

Major

Wildlife, Fisheries and Aquaculture

Degree Name

Master of Science (M.S.)

College

College of Forest Resources

Department

Department of Wildlife, Fisheries and Aquaculture

Abstract

Soy lecithin (SL), a phospholipid rich ingredient derived from soybeans, was tested to evaluate the effects on channel catfish growth and physiological responses. In Trial 1, formulated diets with gradual SL levels were tested. Fish fed 1.5% SL had improved feed efficiency, while 0.5% SL enhanced protein conversion efficiency. The SL influenced cortisol levels during recovery from air exposure stress and improved survival after bacterial challenge. The Trial 2 tested three different lipid sources: Soybean oil (SBO; control), 1% SL + SBO, and catfish oil (CFO). The SL-fed fish also presented improved feed efficiency compared to the SBO group. There were no major differences in survival, blood parameters, or intestinal microbiota, except for higher hemoglobin in CFO fed fish. The SL increased intestinal TNF-α expression, without affecting other immune genes, and conferred better survival after challenge with E. ictaluri. Overall, SL enhanced growth, stress resilience, and disease resistance.

Sponsorship (Optional)

Soy Aquaculture Alliance, Bunge, USDA

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