Velvet Antler Production and Hematological Changes in Male Sika Deers Fed with Spent Mushroom Substrate

SIMPLE SUMMARY: Velvet antler from sika (and other deer species) is a highly valued nutraceutical in traditional Chinese medicine, a market of hundreds of million dollars. Thus, in this case, and in deer breeding in general, reducing the feeding cost of male sika deer is important to improving the profitability of breeding for velvet antlers. Spent mushroom substrate (SMS) is a waste culture medium for mushrooms. The improper handling of SMS causes environmental pollution. Since SMS can be digested and absorbed by ruminants such as sika deer, replacing SMS with a sika deer concentrate supplement can fully utilize the waste resource of SMS and reduce the production cost of velvet antler. ABSTRACT: At present, spent mushroom substrate (SMS) is a waste resource that is producing a pollution problem in China, and which has some use as animal feed or fertilizer, has not been assessed as a feed for deer. The purpose of this study is to expand the feed of male sika deer and reduce the feeding cost by using the waste resource of SMS. The 10% concentrated supplement was replaced with SMS and the feed intake, apparent digestibility, blood index and velvet production of male sika deer were measured. As the results showed, compared to the control group, the substitution of SMS for 10% of the concentrate supplement decreased the concentration of IgA (p < 0.01), replacing 10% concentrated supplement with SMS of Pleurotus ostreatus (SMS-MP) reduced the intake of organic matter (OMI) and improved the digestibility of ether extract (EE), while replacing 10% concentrated supplement with SMS of Flammulina velutipes (SMS-MF) had no effect on apparent nutrient digestibility, feed intake, velvet antler production, and biochemical indexes. In conclusion, SMS had no effect on serum biochemical indexes and the ratio of the feed weight of the deer supplement to the weight of velvet antler (p > 0.05). At the same time, SMS could reduce the feed consumption and improve the economy by using SMS as a waste resource.