Effects of dietary protein level on dry matter intake, and production and chemical composition of velvet antler in spotted deer fed forest by-product silage

The aim of this study was to provide basic information to allow improved nutritional management for velvet production by investigating the effects of dietary protein levels on dry matter intake and production and chemical composition of velvet antler in spotted deer (Cervus nippon). Twenty-four spotted deer stags were assigned to 4 unreplicated groups, Control (15% CP in diet, higher dry matter), CP 10 (10% CP), CP 15 (15% CP) and CP20 (20% CP). The velvet antlers were harvested from each stag on the 55th day after casting of the buttons from the previous set, measured for their size and weight, and the chemical composition of each antler was determined in three sections (top, middle, and base). Dry matter (DMI) and crude protein (CPI) intake were highest (p < 0.05) for the Control and increased progressively (p < 0.05) with increasing dietary protein level. Although not significant, mean length and girth of the main antler beam tended to be larger in either left or right beam with increasing protein level in the diet, longest in CP20 and shortest in CP10. Velvet antler production was lowest in CP10 and highest in CP20, which differed significantly (p < 0.05). Only negligible differences were found between groups in chemical composition. It is concluded that dietary protein clearly influenced dry matter intake and velvet antler production, whereas there was comparatively little effect of dietary protein on chemical composition of antler in spotted deer.