Relationship between some chemical components of herbage, dietary preference and fresh herbage intake rate by the Japanese serow

The serow is a native Japanese mammal and has been designated as a special natural treasure. However, it has been a pest of crops since the 1970s. Since the serow is an indigenous and protected species, it must be controlled without endangering the animal itself. To do this, it is necessary to determine if the serow selects particular crops to consume, and if so, what components of the crop plants influence this choice. In Experiment 1, we measured the preference of four serows for two crop plants and three wild plants, using the cafeteria method. The plants were offered to the animals from 09.00 to 15.30. The serows preferred crop plants to wild plants. The crude protein content of crop plants (28.0 and 32.7%) was higher than that of the other plants (P < 0.05). Dry matter (DM) intakes per hour correlated positively with crude protein content (P < 0.01) and negatively with nitrogen free extract content (NFE) (P < 0.05) and acid detergent fibre content (ADF) (P < 0.01) in the offered plants. In Experiment 2, the food intakes of 17 plants consisting of 6 crops and 11 wild plants were measured. Individual 300 g samples from each plant were offered for 20 min. The serows ate the crops and the forbs in preference to the tree leaves. They consumed little of the conifer tree leaves and the grasses. The dry matter intake and the ADF content were negatively correlated (P < 0.05). The dry matter intake and the crude protein content were positively correlated (P = 0.054). A multiple regression formula was constructed as follows: Y = 1.65CP + 0.56NFE + 0.38DM - 57.45, R₂ = 0.54, P = 0.016 The feeding characteristics suggest that crops might be selected and ingested by the serows because of their higher crude protein, NFE and the dry matter contents.