Lactoferrin peptides are bioactive small peptides generated through enzymatic hydrolysis of lactoferrin and exhibit multiple biological activities，including antibacterial，antiviral，anti?inflammatory，immunomodulatory， and intestinal barrier protective effects，often showing higher bioactivity than intact lactoferrin. However，their large? scale application is limited by the high cost and low yield of natural extraction. Genetic engineering technology provides an efficient strategy for the scalable production of lactoferrin peptides. This review systematically summarized the construction strategies of recombinant lactoferrin peptide ? producing strains，focusing on different expression systems，including Escherichia coli，lactic acid bacteria，and fungal hosts such as Pichia pastoris，as well as key technical approaches including codon optimization，fusion tags，tandem expression，chromosomal integration，and signal peptide screening to achieve stable and high?level expression. Additionally，the mechanisms of action of these recombinant strains are discussed，where secreted lactoferrin peptides and synergizing with host probiotics，exhibit antibacterial， antiviral， immunomodulatory， and intestinal barrier repair activities. In practical applications， recombinant strains ? secreting lactoferrin peptides have shown beneficial effects on disease resistance，growth performance，and immune enhancement effects in animals such as newborn piglets，weaned piglets and poultry. Furthermore，formulation strategies such as microencapsulation can improve gastric acid tolerance and intestinal colonization capacity，highlighting their potential as promising. With continued advances in genetic engineering and formulation technologies，recombinant lactoferrin peptide?secreting strains are expected to play an important role in animal health and sustainable livestock production.