Abstract
Forage intake of grazing sheep was estimated to provide basic data to calculate the carrying capacity of a forest-steppe zone in Mongolia, and the methods were discussed. A vegetation survey and sampling were conducted during September, 2011 and April, 2012 using 12 castrated sheep, which had been born in spring of the previous year. Forage intake was calculated based on the fecal output and the digestibility determined from acid detergent lignin (ADL) contents. The aboveground biomass on a dry matter (DM) basis was highest in September (1.252tDM/ha), and had decreased by 71% in February (P < 0.05). Body weight (BW), fecal output, acid detergent lignin contents, DM digestibility and intake were statistically compared by month. BW (kg) was higher in October (45.5) and November (45.7) and lower in February (39.5) and April (37.9) (P < 0.05). ADL content (% of DM) in plants was higher in October (13.13) and lower in September (9.68) (P < 0.05). ADL content in feces was higher in November and lower in September (P < 0.05). DM digestibility and daily intake were in the range of 51.8-63.8% and 1.10-1.89kg, respectively. Daily intake was significantly higher in November than in other months (P < 0.05). The present study results indicate the possibility that the carrying capacity in winter will be lower than those of references.
