Nutritional Physiology of Wild and Domesticated Japanese Sika Deer

The nutritional physiology of Yeso sika deer (Cervus nippon yesoensis, Hokkaido Island) and Honshu sika deer (C. n. centralis, Honshu Island) is reviewed and compared to results from domestic ruminants. Wild sika deer grazed on various types of plants, and the fiber content in these plants was low. The tastes of Yeso sika deer for existing feeds for ruminant livestock resembled those of sheep. Though the digestibility of these feeds in Yeso sika deer was slightly lower than that in sheep, the nutritive values of digestible crude protein (DCP) and total digestible nutrients (TDN) were similar between the two species, suggesting that feed for sheep can be utilized. Therefore, in small-scale farming of Yeso sika deer, the feeding amount in feeding planning can be determined using the feeding standards for sheep. However, when concentrates are fed, correction of TDN is necessary. In large-scale native pasturage, the nutritional intake in summer is adequate because Yeso sika deer graze on various types of wild plants or herbage. In early winter, they mainly graze on sasa (Sasa senanensis), and supplementary food may be necessary to supply TDN. Thus, since Yeso sika deer graze on many types of wild plants, existing feeds for ruminant livestock can be used. In addition, plant biomasses except concentrates that do not cause competition with existing livestock may be effectively utilized in Yeso sika deer, suggesting their importance as animal resources. Many problems must be evaluated before the deer farming industry can grow. In addition to administrative support, research results that enhance deer farming technology must be accumulated as quickly as possible. On the basis of the above research results on the nutritional physiology of Japanese sika deer, analysis of factors that affect fattening and meat quality of deer is necessary.