Melt-Processed AgNP-LDPE Nanocomposites with Balanced Antimicrobial and Mechanical Performance for Livestock-Farming Applications

Abstract Bacterial contamination in livestock-farming and reproductive-management environments creates a need for antimicrobial polymer materials with reliable processability, mechanical performance, and application-related compatibility. In this study, poly(vinylpyrrolidone) (PVP)-stabilized silver nanoparticles (AgNPs) were synthesized and incorporated into low-density polyethylene (LDPE) using a masterbatch-based melt-processing approach. AgNP formation was confirmed by UV–vis spectroscopy, TEM, and FTIR. The synthesized AgNPs showed antimicrobial activity against bacterial isolates from boar semen and sow vaginal discharge, and time-kill analysis demonstrated time- and dose-dependent bacterial inhibition. A 25 kg AgNP-rich LDPE masterbatch was prepared by industrial-scale extrusion, and diluted to produce the AgNP-LDPE nanocomposites containing 50, 100, and 500 ppm AgNPs. The nanocomposites were evaluated in terms of Ag distribution, mechanical properties, thermal behavior, Ag+ release, antibacterial activity, boar semen quality, and fertility performance in sows. Loadings of 50 and 100 ppm maintained or improved tensile performance, whereas 500 ppm reduced tensile strength and ductility. The 50 and 100 ppm nanocomposites exhibited progressive Ag+ release and strong antibacterial activity against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The semen tubes containing 50 and 100 ppm AgNPs showed no significant adverse effects on sperm motility, progressive motility, pregnancy rate, or farrowing rate. These results identify 50–100 ppm as an effective loading range for melt-processed AgNP-LDPE nanocomposites with balanced antimicrobial performance, mechanical properties, and application-related compatibility for livestock-farming applications.