Sarah Kenyon Agronomy Specialist 417-967-4545 KenyonS@missouri.edu
Plant Growth or Yield Putting it Together Quality
Plant Growth or Yield
Sun O 2 CO 2 CHO H 2 O Mineral Nutrients
9 Macronutrient elements: C H O N K P Ca Mg S 8 Micronutrient elements: Mn Zn Cu Cl B Fe Mo Ni Some other elements that are beneficial: Na Si V Co Al
Iowa State University Extension PM 1791 Grass Anatomy
Initially, tillers depend on carbohydrates developed the previous fall. Then as leaf area explodes with additional tillers, new sugars are made Tillers
Legume Anatomy Iowa State University Extension PM 1791
3 primary stages of forage development 1. Vegetative
Tillers emerge from buds in the crown Tiller growth uses stored carbohydrates Plants begin making new sugars Most new sugars supplement carbohydrates to help growth Very little if any is put into storage
Leaves get longer New tillers grow from buds, tillers branch More leaf area speeds up photosynthesis Some new sugars continue to be used in growth Some new sugars stored as carbohydrates
3 primary stages of forage development 1. Vegetative 2. Elongation/Jointing
Leaf growth slows down Photosynthesis continues making sugars Most new sugars stored as carbohydrates Reproductive tillers begin to elongate
3 primary stages of forage development 1. Vegetative 2. Elongation/Jointing 3. Reproductive
Leaf growth stops, formation of stems and reproductive structures Photosynthesis continues making sugars Most new sugars used for seed production Little stored carbohydrates used for seed development
Perennial Production of Seeds Vegetative Tillers Rhizomes Annual Production of Seeds
Iowa State University Extension PM 1791
3 primary stages of forage development 1. Vegetative 2. Elongation/Jointing 3. Reproductive
In Tall Fescue growing point are not removed In Tall Fescue residual stubble contains chloroplasts In Alfalfa many auxiliary buds (growing points) are removed In Alfalfa most chloroplasts are gone
In both plants regrowth seen in light green In Tall Fescue regrowth from intact growing points In Tall Fescue regrowth uses some stored carbohydrates In Alfalfa regrowth from basal buds In Alfalfa regrowth uses most stored carbohydrates
Dry Matter Yield (lb/acre) Dry Matter Yield at Various Cutting Heights 12000 10000 8000 6000 4000 2000 1 inch 2 inches 3 inches 4 inches 5 inches 6 inches 0 Per. Ryegrass Species Tall Fescue
% Leaf Removed % Root Growth Stopped 10 0 20 0 30 0 40 0 50 2 to 4 60 50 70 78 80 100 90 100 To remain healthy, 30% of grass root systems must be replaced annually. Stops root growth 12 days Stops root growth 18 days
Dry Matter Yield (lb/acre) Overgrazing is removing too much of the Dry Matter canopy Yield at Various too often Cutting Heights 12000 10000 8000 6000 4000 2000 1 inch 2 inches 3 inches 4 inches 5 inches 6 inches 0 Per. Ryegrass Species Tall Fescue
Cool Season Grasses Tall Fescue Orchardgrass Warm Season Grasses Native Grasses Bermudagrass Annuals Pearl Millett Winter Wheat
Take Half / Leave Half Residual
Allows plant to recover completely after grazing Recovery of shoots and roots Allows for plant and stand persistence
During grazing periods: control stubble height Keep growing points Provide for good photosynthesis Keep roots growing Between grazing periods: schedule rest periods Allows for photosynthesis Allows leaves to regrow Vegetative reproduction can occur
Short-lived perennials reseed Red Clover Annuals reseed Annual Lespedeza, Crabgrass Grasses are given the chance to spread Bermudagrass Plants are allowed to thicken naturally by reseeding
www.agriseed.co.nz
Incorporates a grazing strategy and rest periods Quality & quantity increases Enhanced forage utilization Persistence increases
Quality
Working definition: high protein, low fiber Measured Components Acid Detergent Fiber (ADF) = cellulose & lignin Neutral Detergent Fiber (NDF) = total cell walls = cellulose, lignin & hemicellulose Nitrogen Minerals Antiquality Calculated Components Net Energy (NE) calculated from ADF Total Digestible Nutrients (TDN) calculated from ADF Digestible Dry Matter (DDM) calculated from ADF Dry Matter Intake (DMI) calculated from NDF Relative Feed Value (RFV) calculated from NDF & ADF Crude Protein (CP) calculated from Nitrogen
1. Maturity The sharpest decrease in quality occurs during the reproductive phase. CP = 13 14% CP = 5-6% During this growth phase plants lose quality by the hour!
What is the boot stage?
Changes in botanical composition and forage quality of forage groups at different maturity stages. Forage Group Leaves CP NDF ------------------------% DM----------------------- Grasses Vegetative > 50 > 18 < 55 Boot 40-50 13-18 55-60 Heading 30-40 8-12 61-65 Mature 20-30 < 8 > 65 Legumes Vegetative 40-50 > 19 < 40 Bud 35-45 17-19 40-46 Early Flower 25-40 13-16 47-51 Late Flower < 30 < 13 > 51 Source: Schroeder, 1996
When 4 th leaf emerges, the first leaf begins to die Most grasses will have no more than 3 live leaves any point in time Pasture quality begins to decline and is wasted The 3 to 3½ leaf stage is the optimum stage for grazing
www.agriseed.co.nz
Iowa State University Extension PM 1791
1. Maturity 2. Plant Part 1 st bite: leaves with low fiber 2 nd bite 3 rd bite: stems with high fiber
CP NDF NeL 1 st bite: leaves low fiber 27.4 38.5 0.79 2 nd bite 22.9 44.6 0.76 3 rd bite: stems high fiber 14.0 60.0 0.67
Crude Protein Content of Pastures 12-Paddock Rotation
Variation in Milk Production Between Pastures
Dry Matter Yield (lb/acre) Dry Matter Yield at Various Cutting Heights 12000 10000 8000 6000 4000 2000 1 inch 2 inches 3 inches 4 inches 5 inches 6 inches 0 Per. Ryegrass Species Tall Fescue
Dry Matter Yield (lb/acre) Dry Matter Yield at Various Cutting Heights 12000 10000 8000 6000 4000 2000 1 inch 2 inches 3 inches 4 inches 5 inches 6 inches 0 Per. Ryegrass Species Tall Fescue
1. Maturity 2. Plant Part 3. Species
Annual & Perennial Cool-Season & Warm-Season Grasses & Legumes Forbs & Browse
Palatability of Cool-Season Forage Grasses Univ. of Wisconsin Specie Variety Palatability* Orchardgrass TAKENA 4.3 Timothy CLIMAX 4.3 Perennial Ryegrass KEMAL 4.2 Orchardgrass BARIDANA 4.0 Orchardgrass DAWN 4.0 Perennial Ryegrass ANACONDA 4.0 Smooth bromegrass BLIZZARD 3.8 Orchardgrass BENCHMARK 3.7 Timothy DOLINA 3.7 Orchardgrass HAYMATE 3.5 Orchardgrass WARRIOR 3.0 Smooth bromegrass ALPHA 2.3 Tall fescue KY 31 1.4 Tall fescue BRONSON 1.2 Tall fescue SEINE 0.6 *Palatability rating 0=0% grazed, 1=20%, 2=40%, 3=60%, 4=80%, 5=100% grazed. Palatability of grasses under grazing is determined by visual estimation of percent defoliation of plots. The visual determination is made midway during mob grazing by beef cows of the grass plots for yield determination.
1. Maturity 2. Plant Part 3. Species 4. Anti-quality Factors
Nutrient Deficiency Grass Tetany Weeds Poison Compounds Nitrate Poisoning Prussic Acid Bloat Fescue Toxicosis
Early spring production Medium to high yield Excellent persistence Good tolerance to: Poor drainage Low soil fertility Drought Heat stress Cold temperatures Insects Nematodes
Fungus found in stem, leaf sheaths & seed Increases progressively season long Minimized in young growth Cannot survive outside of the plant host Roberts and Andrae, 2004
www.agricom.co.nz
Mutualistic Symbiosis Plant providses habitat and nutrition for the endophyte Endophyte (fungus) provides plant with multiple benefits Drought Tolerance Insect Resistance Increase Nutrient Acquisition Grazing Tolerance Others
Produces alkaloids which confer pasture pest resistance but can also cause animal health problems Peramine Lolines Ergovaline
Medicinal Alkaloids Morphine, quinine, atropine, vincristine Addictive Alkaloids Cocaine, heroin, caffeine, nicotine Very toxic in small amounts Strychnine, coniine
Lower conception rates Reduced milk production Reduced feed intake Rough hair coat Increased core body temperature in summer (leads to heat stress) Frozen nose, ears, tails, etc (in winter) Fescue foot
US beef industry over $600 million annually Missouri beef industry over $160 million annually All US livestock sectors over $1 billion (Roberts and Andrae, 2010)
Test < 20% = Low Infection > 55% = High Infection
Endophyte generally necessary for persistence south of this line (West, 1998)
Bouton et al., 2002 www.noble.org
Non-toxic endophytes (Novel or Friendly) Retain persistent qualities Animal performance similar to E- Available Varieties: Jesup Tall Fescue with MaxQ Advance with AR37 Bar-Optima with E34 Others AR4 E- E+ Location Average Daily Gain (lb) Fayetteville, AR 1.43 1.55 0.93 Mt. Vernon, MO 1.21 1.21 0.55 West et al., 1998
Roberts and Andrae, 2004
1. Maturity 2. Plant Part 3. Species 4. Anti-quality Factors
Plant Growth or Yield Putting it Together Quality
Monitor forage before, during and after the grazing event Determines forage availability for livestock Identifies which paddocks to graze, rest, and cut for hay Helps to prevent overgrazing Helps to identify weak pasture stands
Monitor pastures at least twice a month Weekly is better Walking is better than driving
Forage available for livestock in KNOWN Able to construct pasture budgets and establish paddock rotations Able to Adjust: Forage Allocation Number of Cattle in Paddock Number of Days for Grazing
Write down pasture measurements and management decisions Rest Periods Number of Cattle on Pasture/ Days Cattle are on Pasture Forage Demand Paddock Rotation Schedule Many More
Write down pasture measurements and management decisions
Grazing Wedge http://plantsci.missouri.edu/grazingwedge/
Ranchers should adopt the philosophy that pasture production is their business. Therefore, the health of the pastures is the most important aspect of ranching.
THANK YOU!
Observe pasture growth regularly Yield Stand Density and Health Over time can help to identify: Low producing paddocks Need to weed control Management strengths and weaknesses
Allow adequate rest between grazing for plant recovery Begin Grazing at the 3 3 ½ leaf stage Harvest hay during the boot stage Manage stands for improved pasture quality Keep pasture records!!!
Questions?