| More than half of the land on Earth is used for grazing,and grasslands are the primary source of food for grazing animals.Around one-third of the world’s population is fed by plant production,which makes up 30% to 35% of the total global production and supports almost half of the world’s animal production.A widely used strategy to lessen grazing pressure in local pastures is seasonal grazing rotation,and systematic study on the relationship between vegetation and livestock has not been done in great detail.This study made use of the Huanxian Grassland Agriculture Experimental Station of Lanzhou University’s regional rotational grazing platform,which had four grazing rates(SR0,SR2.67,SR5.33,and SR8.67)and two grazing seasons(winter and summer).investigating how permanent grazing can modify the vegetation of grasslands,influencing the rumen a microbiome enzyme activity,and ultimately the behavior and production of animals.The following are the major research findings from 2021 to 2022:1.Grazing Season and Grazing Rate Effects on GrasslandTan sheep feed on grass that has a higher nutritional value in the summer than it does in the winter.In comparison to winter grazing regions,the crude protein(CP)and energy content of grass in summer grazing areas rose by 21% and 7%,respectively.The amount of neutral washing fiber(NDF)and acid washing fiber(ADF)both fell by 21%and 28%,respectively.The CP content of summer pasture grass falls with increased grazing rate,whereas NDF and ADF content rises and the neutral washing fiber content of winter pasture grass rises.Forage quality during the grazing season had interpretive degrees of CP,energy,NDF,and ADF of 78%,48%,62%,and 88%,respectively;Grazing rate has an explanatory power of 8%,23%,and 6% on CP,NDF,and ADF in forage quality,respectively;The quality of forage cannot be well explained by the interplay of grazing season and grazing rate.Summer grazing has a lower species richness than winter grazing,and Shannon Wiener,Simpson,Pielou,and the richness of species all declined by 10%,8%,13%,and 9%,respectively.Shannon Wiener,Simpson,and Pielou each had an interpretive degree of 22%,23%,or 25% for community diversity indices during grazing season;The interaction between grazing season and grazing rate significantly explains 15%Shannon Wiener and 13% Simpson.2.How the grazing season and pace affect the grazing habit of animalsTan sheep that are grazing in the summer have 30% more feeding mouths per minute than they do in the winter,and they also use 16%,3%,60%,26%,10%,and 73%less energy for feeding,foraging,and walking than they do in the winter,respectively.Tan sheep with SR2.67,SR5.33,and SR8.67 display a disproportionately high proportion of feeding activity throughout their release and return periods while grazing in the summer.The percentage of time spent eating is 58% to 80%,65% to 90%,and65% to 80% in June,July,and August,respectively.The percentage of time spent ruminating or relaxing is 12%-42%,10%-42%,and 10%-45%,respectively.Tan sheep spent more time walking during winter grazing than other sheep,going from 23% to45% of the time;From 77% to 55% less time was spent engaging in feeding behavior.The number of chews per meal group of Tan sheep gradually increases as the number of rotational grazing months increases.Significantly,the grazing season accounts for86% of the feeding intake per minute,14% of the steps per minute,72% of the total walking duration,38% of the feeding energy consumption,and 61% of the walking energy consumption of Tan sheep;Tan sheep’s 7% feeding intake per minute,77%walking steps per minute,4% total walking duration,18% feeding energy consumption,and 23% walking energy consumption are all strongly explained by their grazing rate;Tan sheep’s 5% walking steps per minute,89% total foraging time,8% total walking time,16% foraging energy consumption,13% foraging energy consumption,and 10%swimming energy consumption are all strongly explained by the interaction between grazing season and grazing rate.3.The Impact of Grazing Rate and Season on Domestic Animals’ Digestion and MetabolismTan sheep consumed 12% more dry matter,36% more crude protein,13% more organic matter,and 20% more crude fat during the summer than they did during the winter.Additionally,it decreased Tan sheep consumption of NDF and ADF by 12% and20%,respectively.Summer grazing enhanced the digestibility of dry matter,organic matter,crude fat,and NDF in Tan sheep by 11%,2.9%,4.1%,and 37%,respectively,compared to winter grazing;it decreased the digestibility of CP and ADF by 5.4% and2.8%,respectively.The grazing season,which accounted for 18%,48%,46%,57%,and 17% of the dry matter,CP,NDF,ADF,and organic matter fed to Tan sheep,significantly explained these eating patterns;The grazing rate significantly explained68%,42%,22%,and 58%,respectively,of the feeding of Tan sheep on dry matter,CP,ADF,and organic matter;The interaction between grazing season and grazing rate on the CP intake of Tan sheep has an explanatory power of 7%.Compared to winter grazing,summer grazing increased Tan sheep’s ability to digest dry materials by roughly 11%.Tan sheep had a dry matter digestibility of 56% in the summer and 50%in the winter,which was 23% and 15% higher than SR8.67,respectively,and was the highest in SR2.67.The grazing season,which accounts for 31% of the explanation of Tan sheep’s digestion of dry matter,and the grazing rate,which accounts for 54% and40% of the explanation of Tan sheep’s digestion of dry matter and organic matter,respectively.The significant interaction between grazing season and grazing rate explains the digestion of ADF by Tan sheep,which is 40%.Summer grazing raised Tan sheep’s total energy intake,digestible energy,excreted nitrogen,and digestible nitrogen by 20%,30%,44%,and 30%,respectively,in comparison to winter grazing;Tan sheep’s nitrogen sedimentation and apparent digestibility decreased by 8.9% and 5.4%,respectively;SR2.67 has the most nitrogen deposition and the highest feeding and digestive energies.Summer grazing enhanced the rumen protease activity and lipase activity of Tan sheep by 31% and 44%,respectively,in comparison to winter grazing;Tan sheep had lower amylase and cellulase activities by 40% and 47%,respectively.The grazing season significantly explained the amylase,protease,cellulase,and lipase activities that were 76%,26%,74%,and 24%,respectively,in the rumen of Tan sheep;The grazing rate strongly explained Tan sheep’s 24% rumen protease activity;The 31% activity of rumen protease in Tan sheep is mainly explained by the combination between grazing season and grazing rate.Summer grazing of Tan sheep decreased their rumen microbiota Chao1,observed parameters,PD whole tree,and Shannon index by 7%,11%,7%,and 2%,respectively,in comparison to winter grazing.The Chao1,observed specifications,and PD whole tree indices in the rumen of Tan sheep,which were 16%,30%,and 20%,respectively,were all significantly explained by the grazing season;The grazing rate greatly contributes to the 18% Chao1 index in the rumen of Tan sheep;The Chao1 and PD whole tree indices,which are 28% and 26%,respectively,in the rumen of Tan sheep,are strongly explained by the interplay between grazing season and grazing rate.Summer grazing raised the total volatile fatty acids,butyric acid,valeric acid,and isovaleric acid by 39%,53%,106%,and 20%,respectively,in the rumen of Tan sheep compared to winter grazing.Additionally,it decreased the acetic acid,isobutyric acid,and p H of the rumen of Tan sheep by 4%,3%,and 52%,respectively.The Tan sheep’s rumen p H,total volatile fatty acids,acetic acid,butyric acid,isobutyric acid,valeric acid,and isovaleric acid,which were 48%,92%,35%,89%,93%,75%,and 67%,respectively,were all significantly explained by the grazing season;The total volatile fatty acids,acetic acid,butyric acid,and valeric acid in the rumen of Tan sheep,which are 6%,26%,3%,and 6%,respectively,are strongly explained by the grazing rate;The rumen acetic acid,butyric acid,isobutyric acid,and valeric acid concentrations of Tan sheep,which are 18%,5%,3%,and 11%,respectively,are significantly explained by the interaction between the grazing season and grazing rate.Summer feeding increased the albumin,blood sugar,BUN,triglyceride,and superoxide dismutase concentrations in the serum of Tan sheep by 11%,15%,21%,18%,and 18%,respectively,over winter grazing,while decreasing the concentration of malondialdehyde by 30%.Grazing season significantly accounted for the concentrations of serum albumin,blood glucose,uric acid,BUN,triglycerides,superoxide dismutase,and malondialdehyde in Tan sheep,which were 53%,65%,9%,93%,59%,82%,and 93%,respectively;The concentration of blood total protein,albumin,uric acid,triglycerides,superoxide dismutase,and glutathione peroxidase in Tan sheep was 35%,27%,30%,32%,15%,and 64%,respectively;the grazing rate significantly explained these concentrations;Tan sheep’s 39% serum uric acid content is explained by the substantial association between grazing season and grazing rate.4.How Grazing Season and Rate Affect Livestock ProductivityTan sheep were more productive when grazing in the summer than they were when grazing in the winter.The factors that have the greatest favorable effects on cattle weight are the amount of acidic washing fiber in the forage,the number of intake per minute,the intake of acidic washing fiber,the digestibility of crude protein,nitrogen deposition,rumen amylase activity,and rumen observed parameters;The factors that have the biggest negative effects on animal weight are grass energy,walking steps per minute,protein intake,digestibility of neutral detergent fibers,apparent digestibility of nitrogen,rumen fiber degrading enzymes,rumen valeric acid,rumen Shannon index,and serum triglycerides;The most important factors influencing livestock’s daily weight growth include forage crude protein content,steps per minute,crude protein intake,neutral detergent fiber digestibility,urine nitrogen,rumen lipase activity,rumen butyric acid,rumen Shannon index,and serum glucose.The factors that have the biggest negative impacts on a livestock’s daily weight increase include the acid washing fiber content,total walking time,acid washing fiber intake,apparent nitrogen digestibility,rumen amylase activity,rumen p H,rumen observed characteristics,and serum triglycerides.It is feasible to enhance the protein content of forage and decrease the acidwashing fiber content of forage,depending on the level of vegetation,by providing nitrogen fertilizer to grasslands and adequately extending the grazing season;Based on the control of grazing behavior,such as early grazing in summer,late grazing in winter,late grazing in winter,and early returning,the total walking time can be decreased by increasing the number of steps per minute;By enhancing the digestibility of neutral detergent fibers,rumen lipase activity,and rumen microbial diversity,such as by feeding enzyme preparations,probiotics,and other feed additives,and comprehensively,it is possible to maximize the productivity of Tan sheep based on the process of digestion and metabolism.Such as feeding enzyme preparations,probiotics,and other feed additives,and comprehensively regulating the interaction between vegetation and livestock. |
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