Fig. 2

RS diet suppresses osteoclastic bone resorption in meat ducks. a Tartrate resistant acid phosphatase (TRAP) staining of tibial sections. Bar = 100 μm. b The number of osteoclast (N.Oc/BS) in proximal tibias was determined by histomorphometry. Circulating (c) TRAP activity and (d) C-terminal cross-linked telopeptide of type I collagen (CTx) concentrations. (e) Real-time RT-PCR analysis for mRNA expression of receptor activator for nuclear factor-κB ligand (RANKL) and osteoprogerin (OPG) in the proximal end, and the ratio of RANKL/OPG was calculated. Serum bone formation including (f) procollagen type I N-terminal propeptide (P1NP) and (g) alkaline phosphatase (ALP), as well as (h) serum calcium (Ca) and phosphorus (P) were evaluated. Data are expressed as mean and standard deviation. ^a,bMean values with different letters are significantly different by one-way analysis of variance followed by Tukey’s post hoc test (P < 0.05)