Feedstuff Analysis
Chris Ellason
Feedstuff Analysis
 Feed Sampling
 Proximate Analysis
– Dry matter
– Ash
– Crude Protein
– Ether Extract
– Crude Fiber
– NFE
Detergent Method
 NDF - cell wall components
– cellulose
– hemicellulose
– lignin
– silica
– heat damaged protein
Detergent Method
 ADF - Acid Detergent Fiber
– lignocellulose
 NDF used to predict gut fill and intake
 ADF used to predict digestibility
 ADIN - acid detergent insoluble nitrogen
Know the Form of the Numbers
 Dry Matter Basis
 As-fed Basis
 Air-dry Basis
Energy Measurements
 Gross Energy - GE
– total potential energy of a feedstuff
– determined by bomb calorimeter
 Fecal Energy - FE
– Energy from undigested feed and other
components of feces
– Determined by bomb calorimeter
Energy Measurements
 Digestible Energy - DE
– GE - FE
 Gaseous Products of Digestion - GPD
– combustible gasses that escape during digestion
– mainly methane, traces of H, CO, H2S
 Urinary Energy - UE
– loss of spent metabolites and energy through
urine
Energy Measures
 Metabolizable Energy - ME
– referred to as usable portion of ingested energy
– DE - UE - GPD = ME
 Heat Increment - HI
– heat derived from metabolism or fermentation
of feedstuffs
Detergent Method
 Energy
– NEm
– NEg
– NEl
 These values are calculated from ADF and
NDF
Net Energy - NE
 Net Energy computed by ME - HI
 Includes the amount of energy used for
maintenance plus some production
component
 NEM
– amount of energy expended to maintain energy
equilibrium
Net Energy
 NEM
– basal metabolism
– energy of voluntary activity
– warming of body
– cooling of body
 Net Energy for some production function
Energy Measurements
Common Feeds
 Carbonaceous Concentrates
– High in Energy
– Low in fiber
– Low in Protein
– Variable in protein quality
– fair in P
– low in Ca
Concentrates
 Corn
– high energy
– 8 - 9 % CP
– Low in Lysine
 Sorghum Grain
– Must be processed
– lower in energy than corn
– higher in CP than corn
Concentrates
 Oats
– 75 - 85% energy of corn
– very palatable
– higher in fiber than corn
 Beet Pulp
 Molasses
Concentrates
 Citrus Pulp
 Animal Fat
 Cookie Meal
Protein Feeds
 Soybean meal
– low in Ca
– most complete in energy and protein
 Cottonseed meal
 Peanut Meal
High Moisture Feedstuffs
 Green Chop - forage chopped in the field
and fed without further processing
 Silage - forage cut wet and put through
controlled fermentation
Vitamins and Minerals
 Add Vitamins to assure adequate amounts
 Mineral supplementation
– all minerals are not created equal
– greater absorption of sulfates over oxides
– example CuS vs CuO
Feed Additives
 Antibiotics
– Chlortetracycline
– AS700
 Growth Stimulants
– ionophores - Bovatec, Rumensin
 Others
– MGA - used to stop heat
Problems Associated with Grain
Feeding
Non Ruminants
 Enteritis
– Characterized by inflammation of stomach and
possibly SI
– Antibiotics in starter rations can control this to
some degree
 Dietary changes, erratic feed intake and
weaning stress
 Also grain overload or highly fermentable
feeds
Non Ruminants
 Laminitis (founder)
 Inflammation of the laminae
 Typically a result of poor grain/fiber
balance
 Excessive grain consumption results in
excessive lactic acid production
Ruminants
 Enterotoxemia – over eating disease
– Increase in clostridial organisms
 Severe kidney damage and pin-point
hemorrhages in intestine
 Clostridial vaccination
Ruminants
 Lactic acidosis – grain overload
 Overgrowth of bacteria which prefer lower
pH environment
 These are the starch digesting bacteria
 As they increase pH drops further
 Primarily due to their production of lactic
acid
Ruminants
 If unchecked acids can be absorbed into the
bloodstream resulting in metabolic acidosis
 Endotoxins and histamine can result in
founder
 Liver abcesses
 Acidosis can occur in either acute or
chronic form
Polioencephalomalacia (PEM)
 Primarily caused by over eating grain
 Organism in grain causes ruminal
production of Thiaminase
 Causes an acute thiamin deficiency
 Other PEMs can occur by intakes of high
sulfate water or feed
– This type is not responsive to thiamin treatment
What to watch for
 Dairies – low butterfat
 Humping of back
 Kicking at stomach
 Altered intake
 Fever
What to watch for
 Gut sounds and motility
 Rumen pH
 Cud chewing
 Feed sorting
 Hoof problems (softening, white line, sole
abcesses)
 General unhealthy appearance (eyes, ears
etc.)