Introduction to Grazing Management

Introduction to Grazing Management Blaine E. Horn, Ph.D. Rangeland Extension Educator Big Horn Mountain Area What is Grazing? • Grazing is the process whereby animals consume plants to acquire energy and nutrients to be used for growth and maintenance. • It is an ecological process in that the energy captured and stored by primary producers is consumed by primary consumers. What Grazing is: • Grazing is also an agricultural process in that the grazers themselves and their byproducts are often used by humans as either foodstuff or items of comfort. • Thus, grazing is a form of animal agriculture and the primary form of rangeland agriculture. What is Grazing Management? • Grazing management is the process whereby grazing and browsing animals are manipulated so as to accomplish a desired result. • “Desired results” may range from single goals: – Production of livestock products or picturesque aesthetics • Or multi-use goals: – Acceptable levels of livestock production coupled with maintaining quality wildlife habitat and ample recreational space. Goal of Grazing Management • Regardless of short- or intermediate-term goals, the ultimate “desired result” is the sustained use of the rangeland resource. • The challenge to the grazier is, as Aldo Leopold stated, “is to live on a piece of land without spoiling it”. Grazing Management • Because grazing management is as much art as it is science. – It should be based on both the knowledge of science and the wisdom of practical experience. • Effective grazing management requires a comprehensive plan to secure the best practicable us of forage resources. – Such a plan must provide for the daily, seasonal, and annual grazing capacity needs of the livestock and/or big game. Grazing Management • Grazing management must also seek to match the quantity and quality of grazing animal unit months (AUMs) produced on the ranch or grazing land unit with the AUM needs of the grazing animals associated with it. Why is Grazing Important? • Range is the largest land resource, encompassing about 50% of the land area of the earth. • Approximately half of the land area of the United States is used for grazing. – 42.5% rangeland and pasture – 7% pastured cropland Importance of Grazing • In Wyoming nearly 90% of the land area is used for grazing: – 88% rangeland and pasture. – 2% pastured cropland • Over 40% of Wyoming cropland is in hay. • Value of rangeland livestock > $57 M. Importance of Grazing • Livestock products provide the major economic return from most rangeland and pastures. • Compared with harvested feeds – whether forages or grains – grazing provides a relatively inexpensive and energy-efficient feed source for livestock production. Importance of Grazing • Beef cattle, sheep and goats are raised primarily as a means of marketing forages, especially those forages that have limited alternative markets. • Grazing of standing forage on range and pasture is the counterpart of machine processing of harvested forage crops. Benefits of Grazing to Plants • Removes older tissue that is less efficient photosynthetically than young tissue. • Increases light intensity to lower younger tissue. • Increases stomatal resistance promoting water conservation. Benefits of Grazing to Plants • Recycles nutrients available in urine and dung. • Speeds senescent forage breakdown by trampling. Benefits of Grazing to Society • Low fossil fuel expenditure per pound of livestock weight gain. • The utilization of otherwise mostly idle nonproductive land. • Production of animal protein necessary for meeting nutritional needs of people. Benefits of Grazing to Society • Increase rural income. • Release of feed grains for human consumption. • Soil productivity, as well as water and air quality, is better maintained under the permanent vegetative cover of well-managed grazing lands than virtually any other land-use system. Principles of Grazing Management • Grazing management is principally involved in managing and manipulating the grazing animal-forage plant-soil complex to obtain specified objectives. • This is accomplished by blending ecological, economic, and animal management principles, i.e., rangeland and ranch management. Principles of Grazing Management • Common to the management of all grazing lands must be forage plant considerations: – Plant growth requirements – Plant vigor and reproduction – Defoliation and other animal impacts – Seasonality and fluctuations in forage production Principles of Grazing Management • Equally high in priority are animal considerations: – Animal performance – Animal behavior – Nutrient intake levels – Forage quality relative to animal needs – Forage palatability/animal preference Principles of Grazing Management • Ecological principles: – Energy flow – Nutrient cycling – Primary and secondary succession – Plant-herbivore relationships – Plant competition – Abiotic factors • Climate, topography (aspect and slope), soil (chemistry and texture) Principles of Grazing Management • Ecological challenges: – Necessity to balance solar energy capture and harvest efficiencies to maximize productivity on a sustained basis. • Primary productivity is inherently low because rangeland environments seldom provide an optimum plant growth environment. • Temporal and spatial variation in climatic conditions. • Selective grazing. Principles of Grazing Management • The fundamental principle of grazing management is to control the frequency and severity of defoliation of individual plants. – The principle factor controlling such is grazing pressure which is defined as the ratio of forage demand to forage available for any specified forage at any instant. Principles of Grazing Management • Management tactics to alter grazing pressure (control forage demand) are: – Stocking rate – Season of use – Livestock distribution – Kind/class of grazing animals – Grazing system or method Principles of Grazing Management • Stocking Rate: – Number of animals/unit of land/over time • Forage demand increases or decreases in direct response to increasing or decreasing animal numbers and length of time animals are present • Goal – to provide adequate forage for each animal – Leave adequate leaf area to ensure regrowth • Frequency of defoliation • Intensity of defoliation Principles of Grazing Management • Season of Use: – Variation if forage availability over time – Environmental conditions • Soil moisture, temperature, day length – Stage of plant growth • Vegetative or reproductive – Growing season rest • Allow time for growth or regrowth – Facilitated with use of a grazing system Principles of Grazing Management • Livestock Distribution: – Even utilization of the forage resource – Hindered by differences in forage production due to spatial differences in plant species composition and/or plant densities and/or growing conditions. • Cross fencing • Strategic placement of salt, mineral, and watering facilities Principles of Grazing Management • Kind/class of Grazing Animal: – Grazers or browsers – Mature or young stock • Preference for various plant species and/or plant parts vary widely as a function of above • Affects forage demand and thus grazing pressure on any given stand of forage • Topography influences animal use patterns and landscape utilization patterns vary depending upon kind and/or class of animal Principles of Grazing Management • Grazing management tactics designed to assist in balancing forage supply and forage demand center around controlling grazing pressure by altering the kinds and numbers of grazing animals over both time and space. Principles of Grazing Management • The essence of grazing management and the long-term success or failure of any and all grazing management strategies hinges upon management’s ability to control the frequency and severity of defoliation of individual plants over time and space in such a manner so as to meet desired goals.