Effects of different forages on the chemical compositions and antiosteoporotic activities of velvet antlers

Abstract For this study, we aimed to assess the dose–response antiosteoporotic effects of the middle section of velvet antlers (VAs) from sika deers ( Cervus nippon ) fed with different types of fodders. VAs prepared from farmed sika deers fed with feed mixtures containing sorghum distillery residue (VA‐SDR) or without SDR (SDR replaced with hay, VA‐Hay) were divided into upper (VAU), middle (VAM) and basal (VAB) sections. The chemical constituents of the middle sections obtained from each VA type were compared, and their antiosteoporotic activities were evaluated using rats with ovaries removed surgically (ovariectomy, OVX). The VA‐Hay exhibited markedly increased iron and cysteine levels, whereas the VA‐SDR exhibited markedly increased level of alcoholic extract and testosterone. Both VA‐Hay‐ and VA‐SDR‐treated rats exhibited increased femur strength compared with the control group. However, VA‐SDR exhibited greater bone‐strengthening effects than did VA‐Hay. The serum osteocalcin and estradiol levels were significantly moderated in the VA‐Hay group alone. These results suggest that VA‐SDR and VA‐Hay prevent the loss of bone strength, and preserve trabecular architecture connectivity in an estrogen‐deficient state. However, differences in the chemical compositions of different forages may be responsible for the varying antiosteoporotic mechanisms observed. Thus, the addition of SDR in deer forage may enhance antiosteoporosis activity in VAs, and confer considerable economic and ecological benefits.