Table 1.
Ingredients and nutrient composition of diets.
Fig 1.
Diagram of experimental design.
OP, oscillating crude protein concentrations diet; SP, static protein diet.
Table 2.
Stomachus compositus weights and rumen fermentation index in calves fed OP and SP.
Table 3.
Evolution of apparent nutrient digestibility, nitrogen metabolism and energy metabolism in calves fed OP and SP.
Table 4.
Evolution of urea-N kinetics in calves fed SP and OP.
Fig 2.
Analysis of differentially expressed genes (DEGs) in rumen epithelium and liver between calves fed OP and SP.
DEGs in rumen epithelium (A) and liver (B), with red dots represent DEGs and gray dots represent all detected genes; (C) Fold-change of 10 genes determined by both RT-qPCR and RNA-sequencing methods; (D) KEGG annotate the DEGs in liver. OP, oscillating crude protein concentrations diet; SP, static protein diet.
Table 5.
Gene ontology analysis of differentially expressed genes in rumen epithelial of calves fed OP and SP.
Fig 3.
16S rRNA genes sequencing analysis of bacterial diversity in rumen fluid.
(A) Phyla- and (B) genera-level composition of the rumen bacteria (top 20); (C) PCA analyses of beta diversity; (D) LEfSe analysis indicated the biomarker bacteria and (E) Histograms of linear discriminant analysis (LDA) for the differential biomarker; (F) KEGG annotates the differential functional genes of bacterial communities. OP, oscillating crude protein concentrations diet; SP, static protein diet.
Table 6.
OTU richness and alpha-diversity indices of rumen bacteria in calves fed SP and OP.
Table 7.
Differential metabolites in the rumen of calves fed OP and SP.
Fig 4.
Thermogram of Pearson’s correlation between bacterial abundance (at the (A) phyla- and (B) genera level) and fermentation index. The fermentation indexex included pH, acetic acid/propionic acid (A/P), and the concentrations of NH3-N, acetic acid (AA), propionic acid (PA) and butyric acid (BA).
Fig 5.
Thermogram of Pearson’s correlation between discriminative bacteria and differential metabolites in rumen.