Effect of an Aspergillus oryzae-derived Postbiotic Additive on Growth Performance and Metabolizable Amino Acid Availability in Growing Dairy Heifers

Chapter 1 of this thesis introduces the need for dairy farmers to improve efficiency and decrease nitrogen loss in their herd. The chapter discusses the protein and amino acid requirements of dairy heifers, introduces the use of feed additives, and how Aspergillus oryzae could be a valuable ingredient to improve feed efficiency through increased amino acid availability. Chapter 2 investigates the impact of supplementation with an Aspergillus oryzae-derived postbiotic on growth performance, microbial protein synthesis, and amino acid availability in growing dairy heifers. Chapter 3 provides a concise summery of key findings from the study. Overall, this thesis contributes to our understanding of the impacts on supplementing Aspergillus oryzae to growing dairy heifers and provides insights into the effects that supplementation has on amino acid availability needed for protein synthesis.