Role of Forage in Nutrition Natural feed of all herbivorous animals. –Provide a source of energy, protein and fiber etc. Converts poorly digested feedstuffs to highly digestible feeds in the human food chain Necessary for proper functioning of the digestive system of all herbivores especially ruminants –Supplying nutrients for microbial fermentation –Stimulatory effect Muscle tone –Passage rate –Maintenance of epithelium

Forage Defined Vegetable material in a fresh, dried or ensiled state which is fed to livestock. Average fiber content in dry state = 18% Bulky feed with lower energy content concentrates. Forage is used interchangeably with roughage. Lower digestibility than concentrates. Protein content varies from +20 % to 3 %. Forages are generally higher in Calcium and Potassium but lower in Phosphorus than conc. [ ] Higher in fat soluble vitamins than [ ].

% of Feeds for Different Classes of U.S. Livestock 1 (Average) Class of AnimalConcentrates (%) Roughages (%) Beef Dairy Sheep and goats Swine Horses & Mules Poultry All livestock USDA Economic Research Service data for feed years

Forage Types Hay –Alfalfa –Clover –Grasses Timothy Bermuda Brome –Stover Corn Cottonseed Hulls Pasture –Permanent –Rotational # beef/y –Intensive 600# of beef/y –Range Silage –Corn –Milo Haylage –Alfalfa –Grass –Cereal Grains

Hay Defined: –Forage harvested during the growing period and preserved by drying for subsequent use. Magnitude and importance –60+ million acres nationwide –150 million tons –$10 billion annual crop Economics loss from poor hay making. (Billions)

Hay as an Energy Source ItemAlfalfa mature Alfalfa mid-bloom Alfalfa early bloom Analysis, DM basis % Crude Protein (CP) TDN DM Value of 100 DM, $ CP Value TDN Value Total Value Total Value/acre $ 5 tons of Hay 8 tons of Hay

Feedlot Performance Item All Forage DietAll Conc.[] diet Daily feed intake Feed intake % of Body Wt Avg. daily gain Feed gain ratio Average carcass grade Low choiceMed. choice Dressing percentage Marbling score Abundant Rib eye area (sq. in.) Fat over rib (in.) Taste panel evaluation

Feedlot performance: Hi energy versus all Forage ration ItemCalvesYearling Hi-EnergyAll-ForageHi-EnergyAll-Forage LBS. Avg. initial wt Avg. final wt Avg. daily gain

Feed Fats Carbohydrates Proteins Fatty acids|Glycerol Glucose Amino Acids Glycolysis Pyruvate Acetyl CoA Kreb Cycle Urea Cycle Urea excreted in urine Transamination Electron Transport System Energy & Work CoA ATPADP 2CO 2 H+H+ H2OH2O Glycogen

Gross Energy Digestible Energy (DE) (TDN) Metabolizable Energy (ME) Net Energy (NE) Urinary & Combustible Energy Heat Increment Net Energy Maintenance (Ne m ) Net Energy Production (Ne l )

Proximate Analysis Moisture –Dilute nutrient concentration Crude Protein –Quality of Forage Crude Fiber –Structural Carbohydrates, Hemicellulose, cellulose and lignin –Negatively correlated to Nutritive value (less digestible) Crude Fat –Fats and lipids in forage 2.25 times higher in energy than carbohydrates and protein and are highly digestible Ash Nitrogen-Free Extract –Calculated

Chemical Analysis – Detergent Analysis System Neutral Detergent Fiber (NDF) –The lower the value the more the animal will eat –Cell wall material –Comprised of: Hemicellulose Cellulose Lignin Lignified N Insoluble Ash Acid Detergent Fiber (ADF) –The lower the value the more the animal will eat –Highly indigestible plant material in forage –Comprised of: Cellulose Lignin Insoluble Ash

Proximate Analysis Van Soest Method Nitrogen free extract Crude Fiber Soluble proteins, lipids, and minerals Sugars, starches, and pectins Hemicellulose Cellulose Lignin Soluble Cell contents Acid Detergent fiber Neutral detergent fiber

Effects of Quality of Alfalfa Hay on performance of Lactating Cows Stage of Harvest Composition CPNDFADFDDMDMI4%FCM (%) (%)BWLbs./day Pre- bloom Early Bloom Mid Bloom Full Bloom

Effect of 5 Different Qualities of Hay on Daily Feed Cost 1200 cow herd Hay Quality Description CP (%) DM intake (Tons) Conc. [ ] Purchased (lbs.) Purchased Feed Cost ($) Early cut Legume Legume Mixed, Mainly Legume Mixed, Mainly Grass , Grass ,

Effect of Quality of Fescue Hay on Cattle Gains Composition Stage of Harvest Lbs. Harvested 1 st cutting CP (%) Digestibility ( %) Intake Per Animal (Lbs.DM) Lb of Hay/ Lb of Gain (Lb.) Gain/Head/ Day (lb.) Late Boot to Head 1, Early bloom 1, Early milk 2,

Relative Feed Value (RFV) Uses NDF and ADF values to compute an index to compare all types of forages. RFV = % DDM X % DMI / 1.29 Where –% DDM = 88.9 – (ADF % X 0.779) –% DMI = 120 / % NDF

Relative Feed Values of Various Forages ForageCPADFNDFRFV Alf., pre bloom Alf. bud Alf. mid bloom Alf. mature Brome, late veg Bermuda, late Orchard Grass,early Orchard Grass, early B Wheat Straw Source: Holland and Kezar 1990.

Effect of NDF Content of Forage on DMI Forage Quality% NDF (Dry Matter Basis) DMI as Percent of Body Weight Excellent Source:Van Soest and Mertens.1985.

% Change in Alfalfa Composition at Different Maturities Harvest Date LeafStem CelluloseLigninCelluloseLignin April April May May May June Source:Burritt et.al. 1984

High Moisture Feeds Silage –Corn –Hay High Moisture Grains Green chop Baglage

Composition of Various Silages Type of Silage Analyses on a Dry Matter Basis Crude Protein (%) TDN (%) Ca (%) P (%) Corn Milo Oats Alfalfa Forage Sorghum

Corn Silage – Excellent Energy Source % Dry Matter 8-9 % Crude Protein pH<4.2 Requires 2-3 weeks for the ensiling process Length of cut 3/8 of an inch theoretical cut Utilizes entire plant which increases land utilization Must be made at proper maturity- Black layer present on kernel Proper oxygen free storage essential- hard packed.

Corn Silage – cont’d Complex sugars and carbohydrates are broken down into lactic acid, acetic acid, and small amount of alcohols and other acids Small quantities of proteins are broken down into ammonia, amino acids, amines and amides Acidity reaches levels where the ensiling bacteria die ending the process. Molds and yeast growth are inhibited unless air is re-introduced. (Secondary fermentation)

High Moisture Corn - Barley Advantages –22-32 % moisture –Reduce drying cost –Harvest earlier –Later maturing – Higher producing yields –Increased feeding value Disadvantage –Large inventory of high moisture grain –Limits market flexibility –May freeze or cause fly problem in warmer months –Handling