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- Inorganic dietary elements required in relatively large amounts for animals to live and function properly
- Essential macro-minerals include:
- Calcium (Ca)
- Phosphorus (P)
- Sodium (Na)
- Magnesium (Mg)
- Potassium (K)
- Sulphur (S)
- Chlorine (Cl)
- Generally required in gram (g) quantities per head per day
- Interact with each other
- Must be supplied in proper quantities and ratios to maintain appropriate animal function
- Most often expressed as a unit of heat
- Quantity of energy available in a feed
- Amount of energy required for an animal to perform a specific function
- One megacalorie is one million times larger than one calorie.
- 1,000 calories (cal) = 1 kilocalorie (Kcal)
- 1,000 Kcal = 1 megacalorie (Mcal)
- 1 Mcal = 106 cal
- Gross feed energy minus energy lost in the feces, urine and gaseous products of digestion
- ME = (gross energy) – (energy in feces) – (energy in urine) – (energy in gases)
- Metabolizable energy is rarely measured
- Measuring gaseous energy loss and urine energy loss is more difficult than measuring fecal energy loss
- Nutritionists often use conversion formulas
- Common formula for beef feedstuffs
- ME = 0.82 × DE ii. Where: ME = metabolizable energy; DE = digestible energy
- Inorganic dietary elements required in relatively small amounts for animals to live and function properly
- Deficiencies and toxic levels are quite
- Essential micro-minerals include:
- Iron (Fe)
- Manganese (Mn)
- Copper (Cu)
- Zinc (Zn)
- Selenium (Se)
- Cobalt (Co)
- Iodine (I)
- Chromium (Cr)
- Molybdenum (Mo)
- Nickel (Ni)
- Generally required in milligram (mg) or microgram (μg) quantities per head per day
- Interact with each other
- Must be supplied in proper quantities and ratios to maintain appropriate animal function
- Common unit of concentration
- Represents how many milligrams of substance analyzed by laboratory are present in one kg of sample
- One milligram is one millionth of a kilogram
- 1 kg = 1,000,00 mg
- “mg/kg” is equivalent to “parts per million (ppm)”
- Animals having digestive system with single compartment or simple stomach
- e.g., swine, horses, humans, etc.
- Contrasts with ruminant animals with digestive system having multiple compartments
- Group of many different types of biochemical toxic to animals
- Common mycotoxins include aflatoxins, vomitoxin, zearalenone, fumonisin, T-2, and others
- Are produced on plants or in feedstuffs by fungi
- Particular problem during weather stress
- May occur during growing season, harvest seasons, or during feedstuff storage
- Computerized instrumental method for rapidly and reproducibly measuring chemical composition of samples with little or no sample preparation other than drying and grinding
- Measures the reflections of near infrared light instead of chemicals to determine values for protein, fiber, energy and other feedstuff components.
- Each major chemical components has characteristic near-infrared light absorption patterns
- Used to differentiate one component from others
- NIRS advantages
- Much faster determination of forage nutritional content
- Less expensive
- Can be very precise
- Accuracy of NIRS depends on appropriate calibration with “wet chemistry” results
- Feedstuff energy available to animal after removing energy lost as feces, urine, gas and heat produced during digestion and metabolism
- Most useful energy estimate for formulating ruminant rations
- Calculated from acid detergent fiber (ADF) results using regression equations developed from digestion trials
- Can be further partitioned into net energy need for maintenance, gain, or lactation
- Estimate of feedstuff energy value used for maintenance plus milk production during lactation and for maintenance plus the last two months of gestation for dry, pregnant cows
¶ Net Energy for Maintenance (NEm)
- Estimate of feedstuff energy value used to keep ruminant animal in energy equilibrium, neither gaining nor losing weight
- Animal requirement affected by environmental conditions, body size, age, condition, and other factors
- e.g. Maintenance requirement increases during cold weather
- Estimate of feedstuff energy value required for increasing body mass (weight gain) above maintenance requirement
- Animal requirement affected by production goals, environmental conditions, body size, age, condition, and other factors
- Residue or insoluble fraction left after boiling sample in neutral (nonacidic and nonalkaline) detergent solution
- Measures structural carbohydrates in plant cell wall
- Helps evaluate forage quality
- Includes lignin, cellulose, and hemicellulose
- Lignin is indigestible
- Hemicellulose and cellulose can be digested in varying degrees
- By microorganisms in ruminant animals; like cattle, goats, sheep
- By hind-gut fermentation in monogastric herbivores; horses, rabbits, guinea pigs
- As plant maturity at harvest increases, plant cell wall content increases, and NDF increases
- Can be used to predict dry matter intake
- NDF gives bulk or fill to the diet
- NDF is negatively correlated with feed intake; as NDF increases, intake decreases
- NDF result most valuable for forages in dairy rations
- Low NDF is usually desirable
- Inorganic ion found in plant tissues and forages
- Can accumulate to toxic levels under stressful growth conditions; frequently during drought
- Concentrations often higher in young plants
- Concentrations in feedstuffs expressed as “nitrate” (NO3) or “nitrate as nitrogen” (NO3-N) a. ppm NO3 = ppm NO3-N * 4.43 b. 1% = 10,000 ppm
- Feedstuff content of carbohydrates, sugars, starches, and major portion of materials classed as hemicellulose
- As received basis: % NFE = 100% - (% crude protein + % fat + % water + % ash + % crude fiber)
- Simple carbohydrates mainly found inside plant cells (cell contents), not in cell walls
- Consists primarily of starches, sugars and pectin
- Are rapidly fermented in the rumen; highly digestible
- Serve as a readily available energy source
- Also called “non-structural carbohydrates (NFC)”
- On dry matter basis: % NFC = 100 % - (% neutral detergent fiber + % crude protein + % fat + % ash)
- Inorganic nitrogen in feed sample that is not in protein forms, but can be used by rumen microbial population or gastro-intestinal tract to synthesize amino acids and proteins
- Common NPN materials are urea, ammonia, and ammonium compounds
- Simple carbohydrates mainly found inside plant cells (cell contents), not in cell walls
- Consists primarily of starches, sugars and pectin
- Are rapidly fermented in the rumen; highly digestible
- Serve as a readily available energy source
- Also called “non-fiber carbohydrates (NFC)”
- On dry matter basis: % NSC = 100 % - (% neutral detergent fiber + % crude protein + % fat + % ash)
- Appeal and acceptability of feedstuffs to animals
- Affected by odor, texture, moisture, physical form, and temperature
- High-quality feedstuffs must be highly palatable
- Feedstuff intake is component of feedstuff quality
- Palatability is required for high intake levels
- Important when animal has opportunity to eat selectively
- Animal may consume most palatable ration components, leaving or refusing less palatable components
- Performance with less palatable feedstuffs may equally good if ration composition prevents animal from eating selectively
- e.g., grinding or pelleting hay of poor palatability with other ingredients rather than feeding hay in long-stem form with other ingredients
¶ Particle Size
- Diameter of granular feed materials (e.g., grains, pellets, mineral particles) and/or length (and sometimes width) of roughage or forage fragments
- Can affect mixing of feed ingredients and/or digestion rate
- Unit of measurement used to state concentration of specific nutrients, compounds or elements present in small quantities
- Units equivalent to 1 ppm:
- 1 milligram per kilogram (mg/kg)
- 1 pound per million pounds
- 1 milligram per liter (mg/L)
- 1 microliter per liter (μL/L)
- One percent (1%) = 10,000 ppm
- Measure of acidity or alkalinity
- Negative log of the hydrogen ion concentration
- Values range from 0 (most acidic) to 14 (most alkaline or basic)
- pH value of 7.0 is neutral (neither acidic nor alkaline)
- Heat from manufacturing processes can affect rumen protein degradability and total digestibility
- Rumen degradable protein (RDP) content commonly estimated from feed composition tables
- Results of in situ or in vitro procedures can vary due to conditions during lab analysis
- Environment during in situ or in vitro analysis may be different from actual on-site rumen environment
- Indicates total nitrogen content of substance compared to nitrogen content of plant protein
- For example, urea is nonprotein nitrogen (NPN) compound
- Contains approximately 45 percent nitrogen ii. Has a protein equivalent of 281 percent (6.25 x 45% N = 281% CP)
- Intercellular polysaccharide
- Carbohydrate occurring in between cells
- Functions as a cellular glue
- Easily degraded in the rumen; like nonstructural carbohydrates
- Does not lower rumen pH; unlike nonstructural carbohydrates
- Does not create acidic condition in rumen
- Composed of long chains of various kinds of amino acids
- Examples: lysine, glycine, serine, valine, glutamic acid, alanine, etc.
- Protein is essential nutrient
- Animals meet protein needs by breaking down plant and microbial protein (formed in the rumen) and reassembling them as animal proteins
- Historical method of quantitative chemical analysis that separates, identifies and quantifies the major categories of compounds in feed mixture
- Expresses six categories of components by percentage:
- Water/moisture (or dry matter)
- Ash (minerals)
- Total or crude protein (total nitrogen × 6.25)
- Total or crude fat (or ether extract)
- Crude fiber (incompletely digested carbohydrates)
- Nitrogen-free extract (readily digestible carbohydrate)
- Term for hydrocyanic acid or hydrogen cyanide (HCN)
- Can accumulate in leaves of certain forages
- Potentially toxic to animals if consumed too rapidly or at high rates
- Expressed as “ppm HCN”
- Toxicity problems most common with sorghums
- More problems with grazing fresh plants than with hay
- Toxicity potential tends to decline with advancing age of plant
- Daily feed allowance for individual animal
- Based on animal requirements, feeding standards, and composition of ration ingredients
- Forage quality term used to rank feedstuffs according to their overall nutritive value.
- Developed primarily for use with legume or legume/grass forages.
- Has no units.
- Combines digestibility and intake estimates into one number.
- Useful for practical forage pricing and marketing
- Based on standard forage to provide average score
- Full-bloom alfalfa hay used as standard forage
- Forage with RFV of 100 contains 41% ADF and 53% NDF (on dry matter basis)
- Serves as quality index when comparing two or more lot of forage
- Forages with RFV value greater than 100 are of higher quality than full bloom alfalfa hay
- Forages with RFV value lower than 100 are of lower value than full bloom alfalfa
- To calculate RFV on dry matter basis:
- Digestible dry matter (DDM) as % of dry matter: DDM = 88.9 – (0.78 × %ADF)
- Dry matter intake (DMI) as % of body weight: DMI = 120 ÷ %NDF
- RFV = (DDM × DMI) ÷ 1.29
- Forage quality index used to rank forages according to their relative nutritive value a. RFQ = DMI × TDN ÷ 1.23
- Where: DMI = dry matter intake as % of body weight; TDN = total digestible nutrients as % of dry matter
- Calculation of DMI for RFQ differs from DMI calculation for RFV
- Are two separate DMI and TDN equations
- Alfalfa, clover, and legume/grass mixtures
- Warm and cool season grasses
- RFQ similar to Relative Feed Value index
- Comparison basis is 100, typical nutritive value of full bloom alfalfa hay
- Has no units
- Compares potential of two or more forages on basis of energy intake
- Useful for practical pricing and marketing of forage
- RFQ unlike Relative Feed Value index
- Accounts for digestible fiber (neutral detergent fiber digestibility, NDFD)
- Based on intake and true TDN instead of DDM
- Includes contribution of other nutrient fractions in addition to acid detergent fiber
- Better predictor of forage quality than RFV
- May better reflect cattle performance
- Bulky and coarse feedstuffs high in fiber (greater than 18 percent crude fiber)
- Lower in energy than most concentrates
- Includes forages, hays, silages, hays, or other dry fodders
- Foregut (or forestomach) of ruminant animals such as cattle, sheep and goats
- Large, hollow muscular organ
- Site of most of fiber digestion occurring in ruminant animals
- Digestion is largely performed by microorganisms (bacteria, protozoa, and fungi) that inhabit the rumen
- 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
- Also called “degradable intake protein (DIP)”
(see “By-pass protein” for more detail)
- Another name of by-pass protein, escape protein, or undegradable intake protein (UIP).
- Material not degraded in rumen
- Is degraded in abomasum (not truly “undegradable”)
- Class of animals having multiple organs working together to accomplish digestion
- Digestive tract consists of:
- Reticulum: involved in rumination and in passage from rumen to omasum
- Rumen: large compartment used for fermentation
- Omasum: removes excess liquid and nutrients moving out of reticuloomasal orifice
- Abomasum: acid-pepsin digestion similar to a monogastric
- Contrast to monogastric animals with simple or singlechambered stomach
- Utilize acid-pepsin digestion to extract nutrition from ingested food
(see “Carbohydrate” for more detail)
- Another name for simple sugars or polymerized sugar
- Completely hydrogenated fat
- Each carbon atom is associated with the maximum number of hydrogens
- Are no double bonds
- Saturated fats tend to have less detrimental effects on rumen fermentation than unsaturated fats
- Are solid at room temperature
- Tallow is example of saturated fat, although approximately 50 percent of the fatty acids are unsaturated
- Green forage that is preserved by anaerobic fermentation processes
- Harvested by chopping forage into storage structure where it is packed or compressed to exclude air
- Anaerobic conditions stimulate production of acetic, lactic, and other volatile fatty acids that reduce pH
- Forage undergoes acid fermentation that retards spoilage and preserves silage
- Examples include corn silage, grass or legume haylage, and high moisture corn
- Substances added during ensiling process
- Enhances production of lactic acid and/or a rapid decrease in silage pH
- Normally expressed as percent of crude protein
- Intracellular carbohydrate; found within the cells.
- Found primarily in the grain or seed and/or root portions
- Readily available source of energy
- Complex carbohydrates that form plant cell walls
- Includes cellulose, hemicellulose, lignin and pectin
- Typically measured as neutral detergent fiber
- Feedstuff or mixture used to improve nutritional value of ration
- Helps produce more complete ration in combination with base feedstuffs
- Measure of the energy value in a feedstuff
- Less accurate than net energy values when formulating diets containing both forage and grain
- Known to over-estimate energy value of roughages compared to grains
- Does not account for additional energy losses, especially regarding ruminant systems
- Often calculated from ADF results alone
- More accurate, but more involved method includes:
- crude protein
- 48-hour in vitro NDF digestibility
- NDF insoluble crude protein
- ether extract
- ash
- After lipid extraction, total fatty acids are commonly converted into their methyl esters (fatty acid methyl esters, FAME) prior to chromatographic analysis
- More accurate measure of the true fat content than ether extract
- Uniform mixture mechanically mixed ration ingredients
- Typically includes roughages, forages, grains, and concentrates in one feed
- Used to optimize animal performance
1. Extent to which substance or substances can exert poisonous effect on animals
- Fat having one or more double bonds; not completely hydrogenated
- Non-protein, organic nitrogenous compound
- Made synthetically by combining ammonia and carbon dioxide
- Has 45% nitrogen content or 281% crude protein equivalent
- Organic compounds that typically function as parts of enzyme systems
- Essential for many metabolic functions
- Linear short-chain aliphatic mono-carboxylate compounds, such as acetic acid, propionic acid, and butyric acid
- Are building blocks of different organic compounds;
- Have two to six carbon atoms.
- Are products of ruminal fermentation
- Ruminants mainly produce acetic acid, butyric acid and propanoic acid.
- Are major source of energy for ruminant animals, about 70%
- Used primarily by microorganisms for reproduction and growth
- Excess production used by the ruminant itself
- Influences methane production in the rumen
- Carbohydrates that can be solubilized and extracted in water
- Includes monosaccharides, disaccharides and some short chain polysaccharides (mainly fructans)
- Are major form of storage for carbohydrates in some cool season grasses (e.g., timothy)
- Collectively refers to group of scientific techniques involving direct analyses of a feedstuff sample
- May involve use of solvents, acidic or basic solutions, other chemicals
- Includes other traditional laboratory methods; such as various drying and burning (ashing) procedures
- Most accurate methods for determining feedstuff nutrient values
- Is basis for calibration of NIRS methods
- Is basis for all instrument-based, analytical methods
- Frequently used for quality assurance purposes
- Used in development of new techniques or calculations
- Disadvantages
- Analysis requires that sample is to be destroyed
- Requires more time than certain other methods (such as NIRS)
Saha, et. al. 2013. Common Terms Used in Animal Feeding and Nutrition University of Georgia Cooperative Extension Bulletin 1367. 20 pg.
McGuire, M.A. Nutrition and Feed Terms. Dairy Cattle Management cooperative course materials. University 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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