Managing Natural Resources Stocking Rate, Carrying Capacity & Animal Units Gillespie County Beef & Range Field Day May 12, 2011 R.K. Lyons R.V. Machen
Goals Personal Resources Soil Plants Animals How are they related?
I love ground nesting birds, especially quail. How can I draw them into the yard? How are these goals related?
What is Job One?
Yellow Indiangrass Little Bluestem Big Bluestem Switchgrass Wright s Threeawn KR Bluestem Prairie Coneflower
Wildlife Management
How can I monitor progress toward achieving my goal(s)? Range Health
Why is Rangeland Health Important? Robert K. Lyons, Ph.D. Extension Range Specialist
Rangeland Health Definition Degree of sustained integrity of: Soils Ecological processes Photosynthesis Nutrient cycling
Rangeland Management Standard Minimum: prevent human induced loss of rangeland health
Rangeland Health Thresholds Healthy At risk Unhealthy
Health Criteria & Thresholds Soil Stability Healthy At Risk Unhealthy No movement Moving on site Moving off site
Nutrients/Energy & Thresholds Plants & Litter Healthy At Risk Unhealthy Good distribution Fragmented Fragmented; large barren areas; pedestaled plants
Leaf Removal & Root Growth 100 80 Reduced Root Growth, % 60 40 20 0 0 20 40 60 80 100 Leaf Volume Removed, %
Heavy, Frequent Defoliation Reduces root growth & size water infiltration water absorption nutrient absorption Loss of competitive advantage
Forage Residue Levels Vegetation Type Lb./ac Minimum Stubble Height, in Tallgrass 1200-1500 12-14 Midgrass 750-1100 6-8 Shortgrass 300-500 2-3
How grass grows
How Grasses Grow Growing point close to ground protected produce leaves 1-2 yrs elevated unprotected eaten/makes seedhead: dies
Growing Point Elevation & Grazing Resistance Grass species Growing point elevation/ reproductive tiller ratio Grazing resistance Buffalograss Remain close to ground High Little bluestem Sideoats grama Elevation late w/ large number reproductive tillers Elevation late w/ large number reproductive tillers Moderate Moderate Switchgrass Early Low Yellow Indiangrass Early Low Johnsongrass High number reproductive tillers Low
Rainfall Movement From Range Watersheds Evaporation Transpiration Infiltration Percolation Runoff
Grazing Management Forage Residue & Rainfall Effectiveness Leaving a forage residue Protects soil Increases rainfall effectiveness Increases forage production Forage Production, lbs/ac 4000 3500 3000 2500 2000 1500 1000 500 0 16.9 16.5 100 500 1500 January Forage Residue, lbs/ac 9.7
Animal Unit - relates different animals to a common base forage consumption. An animal unit is the number of animal(s) which consume 26 pounds of forage (DM) per day. 1,000 lb cow 5 sheep 6 goats 7 deer 17 jackrabbits 52 free-range hens
Animal Unit wt. Aoudad 200 Axis 160 Blackbuck 75 Fallow 130 Mouflon 120 Red Deer 450 Sika 145 Whitetail 100 Cattle 1000 Sheep 90 Spanish goat 90 Boer X goat 135 from Exotics on the Range, Mungall & Sheffield, 1994
Animal Unit wt. intake Aoudad 200 0.035 Axis 160 0.035 Blackbuck 75 0.04 Fallow 130 0.035 Mouflon 120 0.035 Red Deer 450 0.03 Sika 145 0.035 Whitetail 100 0.035 Cattle 1000 0.026 Sheep 90 0.04 Spanish goat 90 0.04 Boer X goat 135 0.04 from Exotics on the Range, Mungall & Sheffield, 1994
Animal Unit wt. intake lb/day Aoudad 200 0.035 7.00 Axis 160 0.035 5.60 Blackbuck 75 0.04 3.00 Fallow 130 0.035 4.55 Mouflon 120 0.035 4.20 Red Deer 450 0.03 13.50 Sika 145 0.035 5.08 Whitetail 100 0.035 3.50 Cattle 1000 0.026 26.00 Sheep 90 0.04 3.60 Spanish goat 90 0.04 3.60 Boer X goat 135 0.04 5.40 from Exotics on the Range, Mungall & Sheffield, 1994
Animal Unit wt. intake lb/day AUE hd/au Aoudad 200 0.035 7.00 0.27 3.7 Axis 160 0.035 5.60 0.22 4.6 Blackbuck 75 0.04 3.00 0.12 8.7 Fallow 130 0.035 4.55 0.18 5.7 Mouflon 120 0.035 4.20 0.16 6.2 Red Deer 450 0.03 13.50 0.52 1.9 Sika 145 0.035 5.08 0.20 5.1 Whitetail 100 0.035 3.50 0.13 7.4 Cattle 1000 0.026 26.00 1.00 1.0 Sheep 90 0.04 3.60 0.14 7.2 Spanish goat 90 0.04 3.60 0.14 7.2 Boer X goat 135 0.04 5.40 0.21 4.8 from Exotics on the Range, Mungall & Sheffield, 1994
How many 1,000 lb cow s are out there?
1200 lb 1200 lb Production Stage. Early Lactation Daily Feed.. Good Bermudagrass hay 11% CP, 54% TDN Daily DM intake Daily weight change 25.5 lb -0.98 lb Daily DM intake Daily weight change 27.7 lb -2.88 lb Days to Lose 1 BCS 94 Days to Lose 1 BCS 29 http://www.ansi.okstate.edu/exten/cowculator/
160 lb 100 lb Daily DM intake 5.6 lb Daily DM intake 3.5 lb Head/AU 4.6 Head/AU 7.4 1 AU consumes = 26 lb DM/day
100 lb 180 lb Daily DM intake 4.0 lb Daily DM intake 7.2 lb Head/AU 6.4 Head/AU 3.6 1 AU consumes = 26 lb DM/day
Stocking Rate Carrying Capacity Grazeable Acres
Carrying Capacity, Stocking Rate, & Grazeable Acres Robert K. Lyons, Ph.D. Extension Range Specialist
Stocking Rate vs. Carrying Capacity Stocking rate Acres allotted to an animal Acres/animal unit/year Carrying capacity Stocking rate possible w/o resource damage Numbers not set in stone, only guidelines
Carrying Capacity/Stocking Rate Considerations Take Half-Leave Half Take half 25% to livestock 25% to trampling, insects, decay Leave half Protect soil Plant vigor & protection
Gillespie County Major Soil Component Carrying Capacity Soil Annual Production, lb/ac 25% Production to Livestock, lbs/ac Carrying Capacity, Ac/AUY 1 900-1800 225-450 42 21 2 1801-2800 450-700 21 14 3 2801-3500 700-875 14 11 4 3501-4500 875-1125 11 18 5 4501-6000 1125-1500 8 6
Sandstone Hill 1% Red Savannah 1% Pits Gypsum 0% ShallowGranite 1% Deep Redland 2% Red Sandy Loam 1% Loamy Sand 1% Granite Hill 2% Shallow Ridge 1% Adobe 2% Stony Loam 1% Sandy Loam 1% Granite Gravel Rock 0% Outcrop 0% Serpentine 0% Red Sandy 0% Gillespie County Ecological Sites, % Tight Sandy Loam 4% Sandy 4% Low Stony Hill 23% Steep Adobe 6% Steep Rocky 6% Shallow 16% Loamy Bottomland 8% Redland 8% Clay Loam 11%
Gillespie County Ecological Site, Acres Tight Sandy Loam 28,729 Steep Adobe 38,162 Deep Redland 16,815 Sandy 24,175 Adobe 11,448 Sandstone Hill 4,838 Loamy Sand 9,221 Red Sandy Loam ShallowGranite 5,615 Granite 7,628 Hill 10,138 Shallow Stony Ridge Loam 8,456 5,962 Red Savannah 4,021 Sandy Loam 3,762 Rock Outcrop 2,816 Pits Gypsum 3,207 Clay Flat 3,146 Granite Gravel 1,494 Serpentine 781 Red Dams 11 Sandy 353 Pits Mine 3 Steep Rocky 41,490 Loamy Bottomland 50,864 Low Stony Hill 152,125 Redland 56,107 Clay Loam 75,382 Shallow 110,765
Low Stony Hill Theoretical Carrying Capacities 30 28 25 20 Carrying Capacity, Ac/AUY 15 10 9 14 5 0 Favorable Average Unfavorable Rainfall
Stocking Rate Perspectives Range resource Animal performance
Stocking Rate Considerations Animal Size Proper stocking rate (carrying capacity) example: 30 ac /animal unit/year Animal unit (1000-lb cow) Forage demand, 26 lbs/day 1200-lb cow Forage demand, 1200 lbs x 0.026 = 31 lbs/day Animal unit equivalent, 31 lbs 26 lbs = 1.2 Stocking rate, 30 ac/auy x 1.2 = 36 ac/cow
Stocking Rate Considerations Animal Productivity Proper stocking rate (carrying capacity) example: 30 ac/animal unit/year 1200-lb cow, weaning 500-lb calf Forage demand, 1200 lbs x 0.026 = 31 lbs/day Animal unit equivalent, 30 lbs 26 lbs = 1.2 Stocking rate, 1.2 x 30 ac/auy = 36 ac/cow 1200-lb cow, weaning 600-lb calf Forage demand, 1200 lbs x 0.03 = 36 lbs/day Animal unit equivalent, 36 lb 26 lb = 1.4 Stocking rate, 1.4 x 30 ac/auy = 42 ac/cow
Stocking Rate Considerations Grazeable Acres Ranch/pasture size Brush cover/density Topography Distance to water Forage preference
GPS Collars
Edwards Plateau Ranch 2 Gravelly Redland:Low Stony Hill Preference 2.5:1
90 80 70 60 50 Use, % 40 30 20 10 0 81 73 25 0 1 2 3 4 Brush Density Score
Rock Cover, % Use, % No Use <28 68 32 >28 12 88
Forage Preference
Slope Cumulative GPS Positions, % 100 90 80 70 60 50 40 30 20 10 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 Slope, %
Grazeable Acres Distance to Water Percent Use 0.5 100 1.0 90 1.25 80 1.5 60 1.75 40 2.0 20 2.5 10
Water Access N & S Available Gravelly Redland Low Stony Hill
Water Access Gravelly Redland North Only Low Stony Hill
Water Access Gravelly Redland South Only Low Stony Hill
Edwards Plateau Ranch 3 Gravelly Redland 3% Redland 8% Deep Redland 1% Low Stony Hill 37% Steep Rocky 51%
Edwards Plateau Ranch 3
Edwards Plateau Ranch 3-D View w/ GPS Locations 39% area used 41% GPS points on 9% area SR: 21 ac/cow Effective SR: 9 ac/cow
Carrying Capacity & Stocking Rate How Do You Know Your re Getting it Right? Monitoring: can t set it & forget it Range resource Forage residue Range health indicators Animal performance Body condition scores Gain records
Herbivores Dietary preferences?
Annual Diet Composition, % Cattle Sheep 12 7 81 Grass Forbs Browse 17 22 61 Grass Forbs Browse from What Range Herbivores Eat and Why, Lyons et al., B-6037
Annual Diet Composition, % Goats Deer 12 43 45 Grass Forbs Browse 52 36 Grass Forbs Browse 12 from What Range Herbivores Eat and Why, Lyons et al., B-6037
Approximate Annual Diet % Browse 100 50 0 10 23 50 65 30 % Browse from The Use and Management of Browse in the Edwards Plateau of Texas, NRCS Pub., 1994
Competition Among Deer Kerr Wildlife Area, 1971 96 acre enclosure 6 whitetail deer 6 sika deer No livestock Primary browse Shinoak Liveoak Mid 70 s = record rainfall
Population Dynamics Whitetail & Sika 70 60 50 # head 40 30 20 10 Whitetail Sika 0 1971 1972 1973 1974 1975 1976 1977 1978 1979 W. Armstrong, 1984 Heavy browsing of shinoak No acorn crop All browse depleted
Diet Preference
Thank you