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- Technique to help appraise forage quality
- ADF increases as plant matures
- Highly correlated with cell wall digestibility
- Represents the least digestible fiber portion of forage or other roughage
- Negatively related to digestibility
- Higher ADF, lower digestibility or available energy
- Fiber extracted after refluxing (boiling) with acidic detergent solution
- Includes cellulose, lignin, acid detergent insoluble nitrogen (ADIN), and acid-insoluble ash
- Does not include hemicellulose
- ADF lab result will be lower than neutral detergent fiber result
- ADF often used to calculate energy values
- i.e., total digestible nutrients (TDN), net energy (NEm, NEg, NEl)
- Insoluble protein (nitrogen) fraction remaining in acid detergent fiber residue of feed sample
- Also referred to as “heat-damaged protein (HDP)”
- Represents protein fraction that not degradable during digestion
- Results from heating during storage or processing
- Protein becomes chemically linked to carbohydrates
- Forms indigestible compound
- Escapes ruminal breakdown ii. Considered “unavailable” to the animal
- Adequate estimate of heat-damaged protein in forage feedstuffs
- Not considered good estimate for non-forage feedstuffs
- Protein content adjusted for amount of heat-damaged protein (HDP)
- Used in place of crude protein when ADIN makes up more than 10 percent of crude protein
- If no heat damage, then adjusted crude protein equals crude protein
- Group of mycotoxins produced by some species of genus Aspergillus
- May result from fungal or mold growth in or on
foods and feed
- Are four major aflatoxins
- Identified as B1, B2, G1, and G2
- Are two additional metabolic products
- Known as M1 and M2
- Are direct contaminants of foods and feedstuffs
- Levels are regulated by Food & Drug Administration (FDA)
- Class of nitrogen-containing molecules
- Used extensively for milk and muscle protein synthesis
- Used also for glucose synthesis in liver
- Considered building blocks of proteins
- Two fates when consumed by animal
- Used to synthesize proteins and other biomolecules
- Broken down into urea and carbon dioxide
- Are twenty (20) known standard amino acids
- Eight amino acids considered “essential”
- Animals cannot synthesize essential amino acids from other compounds at essential levels
- Must be obtained from food
- Twelve considered “non-essential”
- Contain amine group, carboxylic acid group, and varying side chains
- Colorless nitrogen compound
- Produced as protein and nonprotein nitrogen degrades or breaks down in rumen
- Can be used to synthesize bacterial protein
- Negatively charged ion or particle
- e.g., chloride or sulfate
- Anionic salts are nutritionally important in dry cow rations
- Aids in prevention of milk fever
- Mineral matter present in feedstuff
- Includes minerals (calcium or silica), dirt, sand, etc.
- Measured by burning sample at high temperature (e.g., 500°C)
- Removes all organic matter
- “% ash” = weight of remaining residue ÷ dry matter
- Results reported on feedstuff natural state, including water
- Affected by sample moisture level before drying
- Also referred to by terms “As-is basis” or “As-fed basis”
- Use “Dry-matter basis” when comparing nutritional value of two or more analyses
- Use “As-fed basis” when mixing a ration for feeding
- Difference between total crude protein and unavailable protein (often heat-damaged protein or ADIN)
- Calculation to estimate "available protein"
- %AP = (1.16 x %CP) - (1.6 x %HDP)
- where: AP = available protein; CP = crude protein; HDP = heat damaged protein
- If calculated AP is greater than CP, then use CP value
- Dry pulpy residue remaining after extracting juice.
- Commonly derived from sugarcane, sorghum, grapes, etc.
- Used as biofuel source.
- Complete feed formulated for specific animal species and class
- Provides appropriate amounts of all nutrients required for maintenance and given level of performance
- Consist of small beets, broken or damaged beets, soil and other foreign material not suitable for sugar production
- Are high in moisture (75 percent to 85 percent)
- Can be quite variable in nutrient content.
- First by-product of milling process
- Includes coarse outer covering of the seed and lesser amounts of flour
- Primarily contains fiber and protein
- Corn, rice, and wheat brans are most common feed brans
- Chemical compound that resists changes in pH with addition (or loss) of acid or base
- Sodium bicarbonate is common buffer
- Are supplemented to reduce risk of rumen acidosis (rumen pH too low)
- Portion of intake protein with slow rate of degradability in rumen
- Fed to escape digestion in rumen
- Allowed to each lower gastrointestinal tract essentially intact
- Digested directly in small intestine as with non-ruminants. This
- Can provide a balance of amino acids unaltered by microbial digestion and synthesis
- Also known as:
- Undegradable intake protein (UIP)
- Rumen undegradable protein (RUP)
- Escape protein
- Unit of heat energy to describe energy available from particular food or feedstuff
- Energy required to raise temperature of one gram of water by one degree Celsius at pressure of one atmosphere
- Biochemical compounds composed only of carbon, hydrogen, and oxygen (C, H, O)
- Polysaccharides: polymers made of basic sugar units, such as glucose (most abundant), fructose, galactose, etc.
- Main source of energy for animals.
- Are two major carbohydrate classes
- Non-structural carbohydrates
- Serve as storage and energy reserves
- Are available for more rapid metabolism to supply metabolic energy
- Sugars, starches, pectins, gums, etc.
- Structural carbohydrates
- Are not used for energy storage
- Fibrous component of cell walls in plant tissues
- Provide rigidity, water transport
- Cellulose, hemicellulose, lignin, etc.
- Less available for energy metabolism than structural carbohydrates
- Positively charged ion or particle
- e.g., potassium, calcium, magnesium, or sodium
- Primary carbohydrate constituent of plant cell membranes
- Unbranched chain of 7,000 to 15,000 glucose molecules
- Major part of structural fiber
- Made available to ruminants through action of cellulolytic bacteria in rumen
- Cellulose = acid detergent fiber - (acid detergent lignin + ash)
- Animal feedstuffs that are high in energy, but low in fiber
- Crude protein content may be high or low
- Includes grains, meals, molasses, many byproducts
- Measure of fat content
- Determined by ether extraction (see “Ether extract”)
- Contains true fat (triglycerides) and other compounds
- Other compounds may be extracted by ether
- Include: alcohols, waxes, terpenes, steroids, pigments, esters, aldehydes, other lipids
- CFat can be estimated in forages by subtracting “1” from ether extract result
- %CFat-forage = %CF – 1%
- Helps account for waxes and other compounds
- Dried cotton boll and attached pedicel of snapped or stripped cotton after lint and seeds are removed.
- Byproduct of cotton ginning industry
- Consists of stems, leaves, burrs, immature seeds, and sand
- Similar to low-quality hay
- Can be used as a low-quality roughage source
- Small, broken, or immature seeds with attached fiber
- Ginning process removes motes at different stage from mature, whole seeds
- Measure of certain structural carbohydrates using sequential acid and alkali extraction
- Includes fibrous cellulose, hemicellulose, and lignin
- Considered indigestible portion of carbohydrates in feeds
- Lab result for CF will be lower than acid detergent fiber result
- Once used as standard analysis
- No longer considered good indicator of forage digestibility in ruminant animals
- Underestimates true fiber
- Accounts for most cellulose
- Includes portion of lignin
- Does not include ash
- Used as legal measurement of fiber in grains and finished feeds
- Is reasonable estimate of fiber in grains because of low lignin content
- Total feedstuff protein
- Measure of total nitrogen in diet
- Includes “natural” protein and non-protein nitrogen sources
- Sample is chemically analyzed for nitrogen content
- Amino acids making up proteins average approximately 16% nitrogen
- For most feeds: %CP = %N x 6.25
- For wheat: %CP = %N x 5.70
- May be further fractionated according to breakdown rate in rumen (e.g., heat-damaged protein)
- 1. Represents portion of crude protein intake that can be digested or degraded to ammonia and amino acids by rumen microbes
- Expressed as percentage of crude protein
- Consists of:
- Non-protein nitrogen (e.g., urea and ammonia)
- True soluble proteins that are
- Proteins with intermediate ruminal degradability
3. Also called “rumen degradable protein” (RDP)
- Technique using detergent solutions to separate digestible and indigestible parts of plant tissues
- Also called “Van Soest” detergent fiber analysis system
- Divides plant cell substances into two classes
- Less digestible cell walls
- Made up of hemicellulose, cellulose and lignin
- Highly digestible cell contents
- Contains starches and sugars
- Milliequivalent (meq) difference between major cations and anions in a diet
- Feeding diets with negative DCAD (anionic diet) in late pregnancy may reduce milk fever problems a. Affected by calcium metabolism
- Calculated using dry-matter percentages of sodium, potassium, chloride, and sulfur
- DCAD, meq/100 grams of dry matter = [(%Na ÷ 0.023) + (%K ÷ 0.039)] – [(%Cl ÷ 0.0355) + (%S ÷ 0.016)]
- Estimates percentage of forage dry matter that is “digestible” or degradable during ruminant digestion
- Calculated from acid detergent fiber values and is similar to TDN (total digestible nutrients)
- DDM% = 88.9 – (ADF% x 0.779)
- DDM decreases as ADF increases
- Provides indication of the actual amount of energy that can be available for animal use
- Estimate of digestible energy equals gross intake energy minus energy lost in the feces (fecal energy) or “DE = GE – FE”
- Commonly used to evaluate poultry and horse feed
- Considered as measure of poultry feed quality
- Fecal energy almost only form of energy loss during digestion
- May over-estimate low quality horse feeds relative to high quality feeds
- Fecal energy only partially accounts for energy losses during digestion
- Large losses occur via urine and gases
- 48-hour “in vitro” digestible fraction of neutral detergent fiber (NDF)
- Expressed as percentage of dry matter content
- Portion of feedstuff which is not water
- Includes protein, fiber, minerals, fats, etc.
- Total weight of feedstuff minus total weight of water in feedstuff expressed as percentage a. DM % = 100% - moisture %
- Nutrient values of feedstuff expressed as percentage of dry matter in feedstuff excluding water content a. Is “moisture-free” basis
- Provides common basis by compensating for large variations in moisture content of feedstuffs
- Eliminates dilution effect of water in feedstuff
- Amount of (or prediction of the amount of) dry matter consumed by given animal or animal type
- Typically expressed as a percent of body weight
- Calculated in different ways
- Anti-quality components may decrease intake
- Tannins and alkaloids may affect taste
- Molds may affect taste or odor and increase feed refusal
- DMI typically increases as forage digestibility of the forage increases
- As neutral detergent fiber (NDF) increases, animals generally consume less
- Relative Feed Value equation includes DMI
- DMI (% of body weight) = 120 ÷ NDF%
- Refers to plant materials preserved by anaerobic fermentation
- Usually in chopped form
- Typically stored in a bag, bunker, wrapped bale or upright silo
- Portion of dry matter extracted with petroleum ether
- Lab test that approximate total fat (or crude fat) content
- Includes true fats
- May also include minor amounts of waxes, plant pigments, esters, aldehydes, and other lipids
- Chemically, fats are called “triglycerides of fatty acids”
- True fat can be measured by determining fatty acid content
- Are a high-density source of animal energy
- Are highly digestible
- Contain 2.25 to 2.8 times energy of carbohydrates
- Often added to boost ration energy levels when intake may be limited due to poor animal health, less palatable feed or environmental stress
- Any acid derived from fats by hydrolysis
- Incudes oleic, palmitic, or stearic acids;
- Have general formula of CnH2n+1COOH.
- Characteristically made up of saturated or unsaturated aliphatic (straight chain) compounds with even number of carbon atoms.
- Vegetative portion of plants in fresh, dried, or ensiled state which is fed to livestock
- Does not refer to separated grains
- Grasses and legumes cut at the proper stage of maturity and stored to preserve quality
- Ability of forage to support desired levels of animal performance (e.g., daily gain or milk production)
- Function of voluntary intake and nutritive value (nutrient content and digestibility)
1. Can be analyzed after conversion to fatty acid methyl esters, (FAME) or directly as free fatty acids after lipid extraction from the product.
- Forages harvested (cut and chopped) in field and fed directly to livestock
- Also called “zero grazing”, “green soiling”, or “soilage”
- Total energy in feedstuff before accounting for losses due to normal digestive, metabolic, and productive functions
- Not useful measure
- Is similar in most common feeds, but does not result in similar animal performance
- Determined by measuring amount of heat produced when feedstuff is completely oxidized in bomb calorimeter
- Dried forage (grasses, alfalfa, clovers) used for feeding animals
(Also see Acid detergent insoluble nitrogen, ADIN)
- Results from exposing feedstuff to excessive heat during processing or storage
- Heating causes chemical reaction (called “Maillard reaction” or “Browning reaction”)
- Irreversibly binds protein to fiber (carbohydrates)
- Proteins become partially or wholly unavailable for digestion
- Calculation to estimate "available protein"
- %AP = (1.16 x %CP) - (1.6 x %HDP)
- where: AP = available protein; CP = crude protein; HDP = heat damaged protein
- If calculated AP is greater than CP, then use CP value
- Plant cell wall carbohydrate that exists along with cellulose
- Cellulose
- Composed only of glucose molecules
- Is unbranched polymer; long chains of glucose molecules
- Hemicellulose
- Composed of many other sugars
- Is branched polymer; chains of 500 to 3,000 sugar units
- Sugars include glucose, xylose, mannose, galactose, and arabinose
- Increasing hemicellulose content typically decreases voluntary feed intake
- Feedstuff is more “bulky”
- Standard unit of potency of a biological agent
- e.g., vitamin, hormone, antibiotic, antitoxin
- Also called “USP unit”
- Technique of performing given biological procedure in controlled environment outside of a living organism a. “in vitro” is Latin for “within the glass”
- Feed analysis carried out in test tubes or tested outside of animal
- Determined by incubating ground feed sample with rumen fluid in beaker or test tube for 24 to 48 hours, followed either by addition of acid and pepsin and further incubation for 24 hours or boiling in neutral detergent fiber solution
- Determined by incubating ground forage sample in porous nylon bag placed within rumen via fistula or port in animal’s side (“in situ”) for fixed time period
- Most often expressed as a unit of heat
- Expresses relative quantity of energy available in feedstuff
- Expresses amount of energy required for animal to perform specific function
- One kilocalorie is one thousand times larger than one calorie.
- 1,000 Calories (cal) = 1 kilocalorie (Kcal)
- 1,000 kilocalories (Kcal) = 1 megacalorie (Mcal)
- Clovers, alfalfa, and similar crops that can absorb (“fix”) atmospheric nitrogen directly through action of bacteria that infect their roots
- Use “fixed” nitrogen as nutrient for growth
- Undigestible, complex carbohydrate compound
- Major structural component of mature plants
- Most commonly occurs in the woody tissues of plant materials
- Contained in fibrous portion of plant stems, leaves, cobs and hulls
- Has negative impact on cellulose digestibility
- As lignin content increases, cellulose digestibility decreases
- Reduces amount of energy potentially available to animal
- Derived from Latin word “lignum,” meaning “wood”
- Organic substance found in plant and animal tissues
- Insoluble in water but soluble in ether, benzene, alcohol, chloroform, and other fat solvents
- Includes glycolipids, phosphoglycerides, fats, oils, waxes and steroids.
- Have a greasy feel
Saha, et. al. 2013. Common Terms Used in Animal Feeding and NutritionUniversity of Georgia Cooperative Extension Bulletin 1367. 20 pg.
McGuire, M.A. Nutrition and Feed Terms. Dairy Cattle Management cooperative course materials. Univsity of Idaho and Washington State University . 6 pg. http://www.webpages.uidaho.edu/avs472/Word/Nutrition/Nutrition%20and%20Feed%20Terms.pdf accessed 01Feb2017
French, P. 2004. Animal Science 312: Applied Animal Nutrition, Feedstuffs and Ration Formulation. Oregon State Univ. Extended Campus, Oregon State Univ., Corvallis OR accessed
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