Module 3 Forage Value/Production

Source of Nutrients -Protein Prebud > Mature Legume > Grasses Quality (amino acid profile) can be hi -Energy Cell contents (nonfiberous CHO) available to non-ruminants/ruminants Cell wall Cellulose, Hemicellulose available to ruminant source of physical/effective fiber -Minerals Legumes > grasses Good sources of Ca, P, K -Vitamins Pasture good source Inactivated with storage and fermentation -Fat little present IMPORTANCE OF FORAGES IN ANIMAL DIETS

Source of Physical Fiber - Gut mobility/environment Rumen Lower GIT - Reguritation - Saliva Production Economics Lower Cost

EXPRESSING FIBER REQUIREMENTS - RUMINANTS Diet contain at least 17% ADF Forage to concentrate ratio dairy cow 40:60, DM basis Forage intake as a % of BW 1 to 1.5% of BW Forage particle length Set harvestor cut at 1/4” to 3/8” results in 15% > 1 1/2” length 25% 3/4 to 1 1/2” length 60% 1/8 to 3/4”

FORAGES Grasses Require N fertilization Examples Brome Orchard Timothy Tall Fescue Bermuda Corn Legumes Fix N Examples Alfalfa Clover Red White Alsike Soybean

Legume Grass SEEDLING DEVELOPMENT

FORAGE YIELDS AND DIGESTIBILITY

ALFALFA PLANT - GROWTH/MATURITION % % Leaf % Stem % Protein Stage of Maturity

STRATEGY FOR FORAGE QUALITY Harvest in prebud stage If many acres need to be harvested - Contract it out - Start early so range encompasses prebud to midbloom - Use combinations of methods to harvest: haylage, balage, grazing - If grazing, rotate pastures. Vary pastures with early, late season grass varieties. - Plant corn varieties varying in maturity date (75 – 120 day)

TOP DAIRY FORAGES Alfalfa – Haylage or dry hay Hi feed value : protein, Ca cuttings/season Hi yield DM/acre Drought tolerant Needs well drained soil pH for max prod Corn –Silage Max yield of feed energy Source of fiber

BEEF FORAGES Pastures/Hay fields - River Bend Farm Combination of grasses Smooth brome grass Orchard grass Tall fescue plus white clover Provides Continuous/close grazing Trample resistant Some species drought tolerant Meets nutrient requirements

Ground forage material Digest with neutral detergent (ND) ND solubles Cell contents ND insoluble fiber Cell wall components Digest with acid detergent (AD) AD solubles Hemicellulose Cell wall N Acid insoluble fiber Digest with 72% H 2 SO 4 Acid insoluble ligninSolubles Cellulose Lignin by loss on ignition VAN SOEST DETERGENT SYSTEM Adopted early 1970’s

CelluloseHemicellulosePectin FructansStarch Pentoses Uronic acids Galactose Pentose pathway Cellobiose Glucose Sucrose Dextrans FructoseMaltose ATP PyruvateLactate Oxalacetate Malate Fumarate + ATP Succinate Succinyl - CoA Methylmalonyl-CoA Propionyl-CoA + ATP Propionate + 2H Acrylate Acetyl-CoA Aceto- acetyl-CoA Acetaldehyde Ethanol ATP Acetate Formate CO 2 H 2 ATP CH 4 2 ATP Butyrate FEED CARBOHYDRATE FRACTIONS RUMEN FERMENTATION

Acid Detergent Fiber (ADF) Highly related to the digestibility of a forage. Neutral Detergent Fiber (NDF) Highly correlated with dry matter intake of the forage. Digestible Dry Matter (DDM) DDM % = 88.9 – (0.779 x ADF %) Dry Matter Intake (DMI) DMI (% of body weight) = (120) / (Forage NDF (% of DM)) Relative Feed Value (RFV) RFV = (DDM x DMI) / (1.29) FORAGE FIBER AND QUALITY RELATIONSHIP

CORN PLANT - GROWTH/MATURITION Grain Cobs & Silk Stalk & Tassel Leaves Fully dented Late dough/early dent Blister { Kernel Maturity/Days % Dry Matter { Plant Late Dough/early dent 35% DM Growth { Harvest for silage

PHASE 1. Cell respiration production of CO 2 production of heat PHASE 2. Production of acetic acid PHASE 3. lactic acid formation begins PHASE 4. lactic acid formation PHASE 5. depends upon phase 4 if enough lactic acid was formed, the silage remains constant If insufficient acid was formed, butyirc acid production begins Protein may be broken down and spoilage may be excessive 69°F 90°F84°FTemperature Change pH Change ACETIC ACID BACTERIA LACTIC ACID BACTERIA AGE OF SILAGE (days) SILAGE FERMENTATION RATE OF SEEPAGE LOSS

SILAGE FERMENTATION

SILAGE PRODUCTION

HARVEST DRY MATTER (DM) AFFECTS SILAGE QUALITY

PUTTING UP SILAGE

NITRATE/NITRITE POISONING The Problem Nitrate can accumulate in plants/stalk Nitrate is converted to nitrite in rumen Nitrite to blood resulting in methanoglopinemia (brown blood, inability to transport oxygen) Solutions Test crop for nitrate content %=safe to feed %=feed with caution introduce to ration gradually increase concentrate ratio to dilute restrict single meal size > 1.00%=Don’t feed Harvesting methodology in a drought Don’t harvest 3 – 5 days after a heavy rain Harvest crop at maturity Harvest hi, leaving stalk, hi nitrate concentration in field Harvest for silage rather than direct feed