Effect of antler growth period on the chemical composition of velvet antler in sika deer (Cervus nippon)

The aim of this study was to provide basic information to allow improved scientific assessment of velvet antlers’ quality by investigating the change of chemical composition depending on antler growth period in sika deer (Cervus nippon). Twelve antlers harvested from sika deer stags (aged 4–5 years) by antler growth periods of 40 days (FDG) and 60 days (SDG) after the casting of antler buttons from the previous set were analysed to compare the chemical composition, such as crude protein, ash, ether extract, amino acid, collagen, glycosaminoglycans (GAGs), uronic acid and sialic acid. The weight of velvet antler in FDG was lower than that of the SDG (P<0.05). SDG had a higher (P<0.05) content of crude ash than FDG. FDG had a higher (P<0.05) content of crude protein than SDG. Amino acid composition was also higher in FDG than in SDG for all sections. The content of collagen was higher in SDG than in FDG for the middle and base (P<0.05) sections. However, collagen levels were exceptionally higher (P<0.05) in FDG than in SDG for the upper section. While the content of collagen was significantly higher (P<0.05) for the upper section than for the middle and base sections in FDG, this was significantly increased (P<0.05) downward from the upper to the base section in SDG. Uronic acid content was higher in FDG than SDG for all three sections but there was no significant difference between groups in the middle and base sections. The content of GAGs was significantly higher (P<0.05) in FDG than SDG for all three sections. The content of sialic acid was the same as that of GAGs. Consequently, in this study, velvet antler production was increased with the extension of antler growth period, but the contents of protein, total amino acid composition, GAGs, uronic acid and sialic acid were decreased and those of ash and collagen were increased. Therefore, it is expected that the quality of velvet antler may be decreased greatly by extension of antler growth period.