Study On Grazing Behavior, Herbage Intake And Digestibility Of Grazing Sheep In The Inner Mongolian Typical Steppe

The study based on the direct observation of grazing behavior and fecal crude protein method and TiO2 external marker to evaluate the impact of different grazing intensities and different grazing systems on grazing sheep in Inner Mongolia Grassland Ecosystem Research Station in July ,2008~September, 2009. The results showed that:1. At six grazing intensities, sheep′s grazing time increased and ruminating, resting and walking time decreased as grazing intensities increased. The grazing time of grazing intensity 9.0 sheep/hm2 was significantly bigger than grazing intensity 1.5 sheep/hm2, grazing intensity 3.0 sheep/hm2 and grazing intensity 6.0 sheep/hm2。The water and salt time of grazing intensity 6.0 sheep/hm2 was significantly bigger than grazing intensity 1.5 sheep/hm2, grazing intensity 3.0 sheep/hm2 and grazing intensity 9.0 sheep/hm2.2. Comparing with the continuous gazing system and rotational grazing system, the grazing time and eating salt and drinking water time of continuous gazing system was significantly bigger than rotational grazing system.3. At six grazing intensities, sheep′s fecal output decreased as grazing intensities increased.The fecal output of grazing intensity 6.0 sheep/hm2 was significantly bigger than grazing intensity 6.0sheep/hm2, grazing intensity 7.5 sheep/hm2 and grazing intensity 9.0 sheep/hm2. The fecal output of grazing intensity 3.0 sheep/hm2 was significantly bigger than grazing intensity 9.0sheep/hm2. The fecal output of continuous gazing system was bigger than rotational grazing system.The water and salt time of grazing intensity 6.0 sheep/hm2 was bigger than grazing intensity 1.5 sheep/hm2, grazing intensity 3.0 sheep/hm2 and grazing intensity 9.0 sheep/hm2.4. At six grazing intensities, sheep′s herbage intake decreased as grazing intensities increased.The relationship among the herbage intake at at six grazing intensities was: grazing intensity 4.5 sheep/hm2 > grazing intensity 3.0 sheep/hm2 > grazing intensity1.5 sheep/hm2 > grazing intensity 7.5 sheep/hm2 > grazing intensity 6.0 sheep/hm2 > grazing intensity 9.0 sheep/hm2. The herbage intake of grazing intensity 3.0 sheep/hm2 and grazing intensity 4.5 sheep/hm2was significantly bigger than grazing intensity 6.0 sheep/hm2, grazing intensity 7.5 sheep/hm2 and grazing intensity 9.0 sheep/hm2。The herbage intake of continuous gazing system was bigger than rotational grazing system.5. At six grazing intensities, sheep′s digestibility increased as grazing intensities increased. The relationship among the herbage digestibility at at six grazing intensities was: grazing intensity 9.0 sheep/hm2 > grazing intensity 4.5 sheep/hm2 > grazing intensity6.0 sheep/hm2 > grazing intensity 7.5 sheep/hm2 > grazing intensity 1.5sheep/hm2 > grazing intensity 3.0 sheep/hm2.The herbage digestibility of continous grazing was bigger than rotational grazing.