Abstract

Background and Aim: Nanotechnology offers innovative strategies to enhance livestock productivity and sustainability. Silicon-containing ultrafine particles (UFPs) have shown potential benefits in animal nutrition, yet their effects on gastrointestinal microbial composition and ruminal digestion in cattle remain poorly understood. This study was to evaluate the impact of dietary supplementation with silicon-containing UFPs on ruminal digestibility, bacterial taxonomic structure, and predicted metabolic functions in the gastrointestinal microbiota of cattle.

Materials and Methods: A 42-day controlled feeding experiment was conducted on 20 Kazakh white-headed bulls (12 months old, 305 ± 10.4 kg), divided into control and experimental groups (n = 10 each). The experimental group received a diet supplemented with SiO₂ UFPs (2 mg/kg feed). Digestibility coefficients were measured using standard methods, and ruminal fluid samples were subjected to 16S ribosomal RNA sequencing and Kyoto encyclopedia of genes and genomes -based functional profiling.

Results: UFP supplementation significantly increased the digestibility of dry matter (3.5%), crude fiber (3.5%), crude protein (5.2%), and organic matter (8.11%) compared to the control group. The experimental group exhibited elevated relative abundances of Prevotellaceae, Lachnospiraceae, Oscillospiraceae, and genera Prevotella, Ruminococcus, and Selenomonas. Functional prediction analysis revealed higher proportions of genes involved in carbohydrate metabolism (e.g., starch, galactose, and amino sugar pathways), lipid metabolism, oxidative phosphorylation, and the biosynthesis of key vitamins and cofactors. Microbial diversity metrics (Chao1, Shannon) indicated significant changes in alpha diversity, with moderate shifts in beta diversity.

Conclusion: Dietary inclusion of silicon-containing UFPs enhances nutrient digestibility and induces favorable modifications in the ruminal microbiota, including functional pathways linked to energy and macronutrient metabolism. These findings support the integration of nanotechnology-based feed additives in cattle nutrition to improve feed efficiency, productivity, and potentially reduce environmental impacts such as methane emissions.

Keywords: cattle, digestibility, feed efficiency, Kyoto encyclopedia of genes and genomes, metabolic pathways, nanotechnology, Prevotella, rumen microbiota, silicon dioxide, ultrafine particles.