The gene expression of pattern recognition receptors (A) and proinflammatory cytokines (B) in milk somatic cells. LC: low concentrate diet; HC: high concentrate diet; HCSB: HC supplemented with 1% sodium butyrate; HCHB: HC supplemented with 1% sodium β-hydroxybutyrate; TLR4: Toll-like receptor 4; PGLYRP2: Peptidoglycan recognition protein 2; TLR2: Toll-like receptor 2; NOD1: nucleotide binding oligomerization domain containing 1; IL-1β: interleukin-1β; IL-6: interleukin-6; IL-8: interleukin-8; TNF-α: tumor necrosis factor-α. The data are presented as means ± standard deviation. For each gene, the columns marked without a common lowercase letter (a, b, and c) on the top indicate significant difference (p < 0.05, n = 6), based on one-way analysis of variance followed by Duncan’s multiple comparison test.