| This thesis studied the response of livestock feeding behavior to different grazing intensities and months from the plant-livestock interaction level,and analyzed the temporal and spatial characteristics of grazing livestock behavior and its correlation with vegetation community environment.The grazing platform of Hulunber National Field Observatory in Inner Mongolia as the test area,six grazing intensities were set by control experiments.There were 3 replicates including control(G0: 0.00 cow.Au/ha),mild(G1: 0.23 Cow.Au/ha),moderate lightly(G2: 0.34 cow.Au/ha),moderate(G3: 0.46 cow.Au/ha),heavy(G4: 0.69 cow.Au/ha),and extremely heavy(G5: 0.92 cow.Au/ha),randomized block group arrangement,and the trial time was from July to September in 2018.G1,G3,and G5 as experimental processing,selected 2 beef cattle in each community to wear GPS collars,used GPS to automatically observe and continuously monitor the geographic location information of livestock,and manually observed the livestock wearing GPS electronic collars in the first ten days of each month and recorded the cattle's behavior such as grazing,resting,and traveling.And then combined automatic observations with manual observations to determine livestock behavior classification standards and analyzed livestock behavior characteristics.Simultaneously,the plant community plot survey was conducted for each treatment,and the plot size was 1 m×1 m.The following important results have been achieved through a series of statistical analysis:(1)Grazing intensity changed the livestock feeding behavior.From the time scale,grazing beef cattle showed a periodic cycle of "grazing-resting-grazing-traveling-drinking" during the day,drinking time was about 3 times as the mark point.During 5:30-18:00,grazing time > resting time > traveling time,grazing intensity made a greater contribution to the behavior of beef cattle compare to the month.With the increasing of grazing intensity,the grazing time of livestock gradually increased,and the resting time gradually decreased,the proportion of grazing time was 53.19%(G1),62.06%(G3),66.60%(G5);the proportion of resting time was 40.84%(G1),34.4%(G3),29.07%(G5);traveling time was 5.97%(G1),2.69%(G3),and 4.33%(G5).(2)Within the 24 h time,the activity rhythm of beef cattle mainly had two peak periods which were 4:00-9:00 and 16:00-22:00 and different grazing intensities are consistent.With the increasing of month,the time range of livestock activities was shortened,starting active after 4:00 in the morning in July and reach the peak of the activity at 6:00 and 20:00,while in August and September the start time of activity in the morning was about one hour later,and the end time in the evening was about an hour earlier,and reach the peak of the activity at 7:00 and 18:00 respectively.The criteria for judging the occurrence of various behaviors according to speed threshold: resting([0,0.075))m/s,grazing([0.075,0.195))m/s,traveling([0.195,+?))m/s.Therefore,the overall behavior of livestock within 24 h was resting time>grazing time>traveling time.With the increase of grazing intensities,the grazing time of livestock gradually increased,and the resting time gradually decreased which had the same trend as daytime,the time proportion of grazing are G1(23.71%),G3(29.35%),and G5(33.27%).(3)On the spatial scale,the spatial behavior of livestock had certain rules in different grazing intensities,they were likely to gather at water points,community entrances and fences and the trajectory of the livestock was more complex,the movement distance was also increasing,the proportion of beef cattle active area gradually increased;on the monthly gradient,the moving distance in August decreased.Considering grazing intensity as the dominant factor,the moving distances of domestic animals were 3526.14 m(G1),4051.41 m(G3),and 4892.27 m(G5),respectively.The range of active areas for grazing livestock increased significantly with the increase of grazing intensity.Under heavy grazing conditions,the area of livestock utilization reached 69.62 %,but the movement distance and range of active areas of livestock did not necessarily show the same trend.The largest range of active areas of livestock is 67.25% in August.(4)The grazing intensity changed the characteristics of the community structure of vegetation.With the increase of grazing intensity,the height,cover and aboveground biomass of the vegetation decreased significantly.On the monthly gradient,the biomass reached the maximum in August;under moderate grazing conditions,Plant diversity was the highest;ADF,NDF,C,OM,and GE gradually decreased with the grazing intensity increased,the changes of C,OM,and GE were also consistent,and the contents of N and CP appeared obvious enhanced under the heavy grazing intensity,and the plants had the highest N content in August.(5)Comprehensive vegetation characteristics,The indexes closely related to the grazing behavior of livestock mainly include canopy characteristics: plant height,density,above-ground biomass and diversity index: simpson index,pielou index and nutrient characteristics that were N,GE,ADF,NDF,plant height was a more sensitive indicator,which contained the obvious effect with livestock behavior.Height,aboveground biomass,livestock movement distance and grazing time were highly negatively correlated.The increase of community diversity index contributed to livestock to grazing.At the same time,it reduced the grazing selectivity of livestock,which was significantly negatively correlated with the grazing time of livestock;the behavior of livestock was significantly positively correlated with N content,and was significantly negatively correlated with GE,ADF,NDF,which meant that cattle preferred to eat protein content,when the plant GE was high,the moving distance and grazing time were short.Compared with the low GE plant,domestic animals did not need to spend a long time to eat to meet their own needs.To sum up,considered grazing intensity and month,grazing intensity had a dominate effect and significantly changed the livestock's behavior.The behaviors of the livestock were closely connected with the vegetation community.Cattle combination with mild grazing intensity was not only conducive to fully grasping the dynamic changes of the behavior of grazing livestock and used GPS signal data to judge the behavior of livestock,but also conducive to the rational utilization of grassland resources and intelligent management of livestock. |
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