低タンパク質食におけるWOD188ブロイラーのアルギニン要求量：成長成績と腸管の健康からの洞察

The efficacy of low-protein diets, an effective approach to the high-quality protein feed shortage, relies on precisely meeting the amino acid requirement of broilers.

This study aims to determine the arginine requirement of WOD188 broilers fed low-protein diets and to assess the effects of arginine on growth performance, intestinal function, and nitrogen metabolism.

Experiment 1: WOD188 broilers (29-d-old, male, n=300) were randomly assigned to a normal-protein diet or four low-protein diets with standardized ileal digestible arginine-to-lysine ratios (SID Arg:Lys) of 96%, 107%, 118%, and 128% (6 cages/treatment, 10 broilers/cage). After 13 days, growth performance were recorded and regarded as the primary outcome for evaluating the arginine requirement. Samples of blood, breast muscle, intestine, and chyme were collected for the analysis of serum parameters, meat quality, intestinal morphology, gene/protein expression, and intestinal microbiota. Experiment 2: A total of 90 broilers (35∼37 days old) were fed the same five diets and collected excreta to measure nitrogen content. Data were analyzed by one-way ANOVA and regression modeling.

A dynamic requirement model for SID arginine intake (Y) was established as Y=1.703×BW^0.70+0.750×BWG. The optimal growth performance and peak nitrogen utilization efficiency were achieved at SID Arg:Lys 107%∼115%. Low-protein diets with arginine supplementation decreased meat pH, fecal nitrogen content, serum TP and BUN levels (P < 0.05), while increasing intestinal villus height and NO levels (P < 0.05). It also upregulated intestinal CAT-2 mRNA expression, barrier-related protein (ZO-1/ Occludin) expression, and decreased IL-10 inflammatory factor levels (P < 0.05). The low-protein diet significantly reduced bacterial α-diversity (ACE and Chao1 index, P < 0.05), LEfSe analysis further identified Lactobacillus as key biomarkers (LDA score > 2.0, FDR-adjusted P < 0.05).

This study established the dynamic arginine requirement model of WOD188 broilers fed the low-protein diet. Dietary arginine enhanced growth performance, carcass traits, and meat quality, while improving intestinal microbiota composition, barrier and transport function, ultimately elevating nitrogen utilization efficiency.