Popis: |
Dietary nutrient manipulation (e.g. protein fractions) could lower the environmental footprints of ruminants, especially reactive nitrogen (N). This study investigated the impacts of dietary soluble protein (SP) levels with decreased crude protein (CP) on intestinal N absorption, hindgut N metabolism, fecal microbiota and metabolites, and their linkage with N metabolism phenotype. Thirty-two male Hu sheep, with an age of six months and an initial BW of 40.37 ± 1.18 kg, were randomly assigned to four dietary groups. The control diet (CON), aligning with NRC standards, maintained a CP content of 16.7% on a dry matter basis. Conversely, the experimental diets (LPA, LPB, and LPC) featured a 10% reduction in CP compared with CON, accompanied by SP adjustments to 21.2%, 25.9%, and 29.4% of CP, respectively. Our results showed that low-protein diets led to significant reductions in the concentrations of plasma creatinine, ammonia, urea N, and fecal total short-chain fatty acids (SCFA) (P |