Physiological and productive parameters of commercial laying hens fed diets including biological silage of tambaqui by-products

Abstract

The objective of this thesis was to evaluate the productive performance and physiological profile of commercial laying hens fed biological silage produced from by-products of tambaqui processing (Colossoma macropomum). The study adopted an integrated approach, encompassing productive performance, physiological responses, egg quality, metabolomic analyses, and economic feasibility. Chapter 1 is a brief introduction to the thesis's problems. In Chapter II, the potential of fish silage as a sustainable strategy was discussed, framing the study within the context of a circular bioeconomy. Chapters III and IV addressed the evaluation of hens at different ages, demonstrating that the inclusion of silage did not compromise productive parameters or the physical, compositional, and sensory characteristics of eggs, while maintaining stable hematological and biochemical indicators. Chapter V applied low-field proton nuclear magnetic resonance spectroscopy (¹H NMR), coupled with multivariate analyses, enabling the identification of modifications in the apolar fraction of the yolk and expanding the understanding of biochemical and metabolic mechanisms modulated by the diet. Finally, Chapter VI integrated performance and cost results, demonstrating improved feed efficiency and reduced formulation costs, thereby confirming economic feasibility. Overall, the results validated the nutritional value of the silage and highlighted its potential to reduce production costs, add value to the production chain, and mitigate environmental impacts. In conclusion, the integration of productive evaluation, physiological and metabolomic analyses, and economic feasibility assessment positions tambaqui biological silage as an innovative and sustainable alternative for egg production, contributing to the strengthening of regional production chains and aligning with the demands for resilient, low-impact food systems.