IN-VITRO DIGESTIBILITY OF SEASONAL FORAGES USED BY WAPITI AND ROE DEER IN NORTHEASTERN CHINA

Seasonal changes in in vitro dry matter digestibility (IVDMD) of five forage classes (browses, sedges, forbs, ferns and the bark of Ulmus sp p.) used by wapiti and roe deer were determined in relation to chemica l composition, using the two-stage technique of in vitro trial with ru men inocula from one wapiti and one roe deer captured in winter. Wapit i and roe deer showed remarkable fluctuation in IVDMD among seasons an d forage classes. IVDMD decreased from 43.8-64.3% in spring to 29.4-40 .5% in winter for wapiti, and from 52.4-77.4% in spring to 25.9-36.5% in winter for roe deer. There was significant variation in IVDMD among species of browses for wapiti and roe deer. IVDMD ranged from 28.5% t o 58.7% in twigs and from 39.8% to 58.2% in leaves for wapiti, and fro m 24.1% to 67.7% in twigs and from 40.0% to 71.7% in leaves for roe de er. Roe deer had higher IVDMD (40.0-71.7%) in both leaves and twigs of browses than wapiti (35.9-58.7%) during snow-free seasons, but IVDMD of twigs was lower for roe deer (25.9-36.5%) than wapiti (29.4-38.4%) in winter. Significant multiple correlation was found between NDF and ADF, and IVDMD in sedges, forbs and ferns for both wapiti and roe deer , whereas only roe deer showed the significant multiple correlation fo r leaves of browses.