Effects of dietary N-carbamylglutamate supplementation on growth performance, meat quality, and cecal microbiota in Huoyan geese.

This study evaluated dietary N-carbamylglutamate (NCG) effects on growth performance, body size indices, meat quality, and intestinal morphology in Huoyan geese, aiming to identify the optimal supplemental dose. Only the control and 0.06% NCG groups underwent 16S rRNA sequencing to explore associations between cecal microbiota and meat quality. A total of 240 one-day-old female geese were randomly assigned to four groups, each with six replicates of 10 birds, and fed a basal diet (control group) vs. basal diets supplemented with 0.06, 0.12, and 0.18% NCG groups, respectively, over a 30-week period. Growth performance, body size measurements, and meat quality traits were assessed, and cecal microbial communities were analyzed via 16S rRNA sequencing. From week 6 onward, the 0.06% NCG group exhibited the highest body weight through week 30, with superior average daily gain during the critical 4-8 week growth phase while maintaining normal average daily feed intake. From week 6 through week 30, the 0.06% NCG group had the highest body weight, with superior ADG during weeks 4-8 and while maintaining normal ADFI. Compared with controls, 0.06% NCG significantly increased body oblique length, shank length, and shank circumference (p < 0.05), and decreased the feed-to-gain ratio during 1-10 weeks (p < 0.05). 0.06%NCG groups also showed significantly increased breast muscle redness (a*) and 24 h postmortem pH (p < 0.05), along with decreased shear force in both breast and leg muscles (p < 0.05). Jejunal villus height and villus height-to-crypt depth ratio were significantly elevated (p < 0.05). 16S rRNA sequencing revealed higher Chao1 and Shannon indices (p < 0.05) and altered community structure in the 0.06% group, notably, short-chain fatty acid (SCFA)-producing bacteria, particularly Ruminococcaceae and Faecalibacterium, were enriched in the 0.06% NCG group. Correlation analysis further revealed that these genera were positively correlated with breast muscle redness (a*) and 24 h pH. Dietary 0.06% NCG improved growth performance, body development, and meat quality in Huoyan geese. The beneficial phenotypes may be linked to altered cecal microbiota enriched in SCFA-producing taxa.