LN33 fermented feed improves growth performance in Cherry Valley ducks by enhancing immune function and intestinal barrier integrity.

Abstract

INTRODUCTION: This study investigated the effects of feed fermented withLN33 on growth performance, antioxidant capacity, immune response, intestinal barrier function, and gut microbiota in Cherry Valley ducks. METHODS: A total of 480 healthy 7-day-old Cherry Valley ducks (197.33 &#xb1; 5.90 g) were randomly divided into four groups. One group received a basal diet (control), while the other three received the basal diet supplemented with 1%, 3%, or 5% fermented feed for 28 days. RESULTS: Ducks fed 3% fermented feed showed significantly higher final body weight (3,020.00 &#xb1; 52.20 g) and average daily gain (100.79 &#xb1; 1.73 g) than the control group (2,896.00 &#xb1; 120.93 g and 96.39 &#xb1; 4.23 g, respectively;< 0.05). The feed-to-gain ratio decreased significantly (1.79 &#xb1; 0.03 vs. 1.87 &#xb1; 0.08;< 0.05), with similar feed intake across groups. Antioxidant enzyme activity increased, while pro-inflammatory cytokine levels decreased. Expression of intestinal tight junction proteins and immune markers improved. The relative abundances of, andincreased significantly and were positively correlated with intestinal and immune function. DISCUSSION: These results suggest that-fermented feed enhances growth performance and overall health in Cherry Valley ducks by boosting antioxidant defenses, modulating immune responses, and reshaping the gut microbiota.