Effects of grazing time restriction on the grazing behavior of Boer goat

The grazing behavior,intake rate and diet digestibility of Boer goats grazing in sowed ryegrass pasture in a replicated 2×2 factorial experiment were studied.Overnight access to ryegrass pasture was designed into two treatments(no grazing in night and continuous grazing) and the forage availability was designed into two treatments as well(6.0 and 3.0 cm of community height),represented high and low availability.Regardless of forage availability,the grazing time of grazing time restricted Boer goats was significantly shortened and on the contrast,their grazing bouts significantly increased,and the total daily grazing time significantly reduced compared with that of unrestricted Boer goats.In response to time grazing restriction,the Boer goat had a significantly higher instantaneous intake rate mainly by larger bite.The grazing time unrestricted Boer goats could not maximize their instantaneous intake rate.The behavioral responses to time grazing restriction were able to counteract the reduction in daily grazing time only where forage availability was high.In contrast,the time grazing restriction led to a reduction in total daily intake while the forage availability was low.The results from four experimental treatments generally supported the hypothesis that total daily grazing time was a key constraint on daily intake in lower vegetation height.