Effects of feeding high-moisture corn on milk quality, serum antioxidant indices and intestinal microflora of Chinese Holstein cows.

Abstract

INTRODUCTION: This study investigated the effects of replacing steam&#x2011;flaked corn (SFC) with high&#x2011;moisture corn (HMC) in the diet of Chinese Holstein dairy cows. METHODS: Forty mid&#x2011;lactation cows (parity 2-3) were randomly assigned to two groups: a control group (YPFY group,&#x202f;=&#x202f;20) fed a diet containing SFC, and a treatment group (GSFY group,&#x202f;=&#x202f;20) fed HMC on an equal dry&#x2011;matter basis, with both diets being isoenergetic and isonitrogenous.The experiment consisted of a 10-day acclimation period followed by a 60-day feeding trial, during which milk quality, serum antioxidant capacity, and intestinal microbiota were evaluated. RESULTS: Although milk yield was unaffected, the GSFY group showed a marked increase in milk fat percentage (&#x202f;<&#x202f;0.01), while lactose, protein, and solids&#x2011;not&#x2011;fat exhibited non&#x2011;significant decreasing trends. Serum antioxidant capacity was significantly enhanced in the GSFY group, as reflected by elevated activities of superoxide dismutase, glutathione peroxidase, and catalase (&#x202f;<&#x202f;0.05). Gut microbial alpha diversity did not change, but beta diversity revealed significant structural separation. At the phylum level, HMC feeding increased the abundance of Bacteroidota while decreasingand. At the genus level,andwere enriched, whereasandwere reduced (&#x202f;<&#x202f;0.05). Correlation analysis indicated a strong link between these microbial shifts and milk composition. DISCUSSION: In conclusion, HMC serves as a superior alternative to SFC, improving milk fat, enhancing systemic antioxidant status, and positively modulating the gut microbiota to optimize milk component synthesis in Chinese Holstein cows.