Date of Award
2026
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Biological and Environmental Sciences
Department
Environmental & Natural Resource Economics
First Advisor
Maria Peterson
Abstract
The development of sustainable feed supplements is a crucial component in addressing the current global need for resilient and environmentally responsible food systems. This dissertation has explored the potential of brown algae (Saccharina latissima) as a sustainable feed supplement for poultry with the potential to benefit production efficiency, product quality, and the global food supply. With both controlled feeding trials and a producer-based survey, the work in this dissertation investigates the nutritional, biological and practical implications of adopting kelp into poultry diets.
Chapter one provides a comprehensive overview of the current literature surrounding the use of marine sources and seaweed in livestock and poultry feeds. Specifically, this review evaluates the use of seaweed for nutritional and environmental advantages in production settings. This review highlights the bioactive compounds, minerals and polysaccharides found in kelp that may enhance animal performance, immunity and product quality. In this chapter, the reproductive physiology as well as nutritional requirements of hens is described, demonstrating how macro- and micro- nutrients from kelp supplementation can affect egg formation, quality and chick hatching success. This chapter additionally discusses the current limitations associated with seaweed use in poultry feeds, including the variability in composition, potential contaminants and heavy metal accumulation, and the lack of standardized feeding guidelines.
Chapter two reports the effects of dietary kelp supplementation on commercial laying hen performance and production. This research described in this chapter monitored hen body weight, feed intake, and egg production in response to a 5% dietary inclusion rate of blanched Saccharina latissima. Results in this chapter report that kelp-fed hens produced more eggs without any adverse effects on the hens body weight or blood mineral content. Findings from this chapter suggest the potential advantages of kelp supplementation for poultry.
To build on these findings, chapter three dives deeper into the effect of kelp supplementation with a focus on backyard flocks, incorporating different breeds to address impact across genetic lines as well as management systems. In this chapter, hens received the same 5% inclusion of blanched kelp as in study one. Supplemented hens produced eggs with shells that were both thicker and heavier, as well as eggs with greater albumen weights and heights than the control hens. These kelp-fed hen eggs also exhibited greater concentrations of iodine than control eggs, and a decrease in selenium content. Combined, these results support the potential use of kelp as a feed additive in poultry diets to improve egg quality and nutritional value. These results also suggest the need for further research to determine if lower inclusion rates are needed.
Chapter four uses a producer survey to understand the current perceptions, needs, and challenges of New England livestock producers when it comes to using sustainable feed supplements. Results of this survey found that New England producers utilize a mix of heritage and dual-purpose breeds on small-scale farms. Respondents of this survey highlighted the interest and current use of seaweed products in tier production, however the desire for more research surrounding them was highlighted. Additionally, respondents reported interests in sustainable supplements that aid in animal health while expressing the need for more research as well as economically viable options.
Overall, this dissertation contributes to the growing body of research looking at marine and seaweed-based feed supplements for sustainable livestock feeding. Through combining feeding trials with producer input and perspectives, this work advances sustainable animal production through linking sustainability, improved nutrition, and producer interests in creating more resilient livestock feeding systems.
Recommended Citation
Clifford, Meghan, "OPTIMIZING POULTRY PRODUCTION AND ENHANCING EGG NUTRIENT COMPOSITION THROUGH KELP SUPPLEMENTATION IN LAYING HENS" (2026). Open Access Dissertations. Paper 4549.
https://digitalcommons.uri.edu/oa_diss/4549