Lecture 11: Feeds & Feedstuffs 1 (Exam 2) Flashcards
List the nutrient categories
- Water
- Energy (Fat & Carbs)
- Protein
- Vitamins
- Minerals
How is water supplied
- Free drinking fresh water
- Water in feed (dry v. wet ingredients)
- Metabolic water (from chemical rxn in the body)
What % water is grass
60%
When should fresh water be available
- Alway ava
- Except after hard exercise in horses
What does consumption of water determine
- Their dry matter intake (DMI)
- Their production situations (dairy cows = need more water)
How is energy provided
- Carbs (starch, hemicellulose, & cellulose)
- Lipids (Solid fats & oils)
- Can be provided by protein if necessary or if protein is fed in excess
What is energy req for
Maintenance, growth, repro (preg & lactation, & production
How is energy often measure
- Kcals (= 1000 cals)
- Mcals (=1000 kcals)
What is crude protein
Essential & non essential amino acids
What type of protein is defined in ruminants
- Degradable intake protein
- Undegradable intake protein
What is degradable intake protein
Protein used by rumen microbes & transformed into microbial protein
What is undegradable intake protein (bypass protein)
- Protein that remains undegraded through the rumen
- Will be available for digestion & absorption in the SI
- Impt to help meet protein needs of high producing dairy cattle
Why is finding the dry matter content via measuring water content by oven drying impt
- B/c knowing the DM content is one way that you can accurately calculate other nutrients
- Need to determine how much an animal will eat of this feedstuff
What is the purpose of a proximate analysis of feedstuffs
Allows us to make legitimate comparisons of feedstuffs on the basis of specific nutrients
How do you get non structural carbs
By calculation
What are the structural components (provide fiber)
- Stem (provides more fiber)
- Leaves
- Primarily cellulose, hemicellulose, lignin from the cell components (resistant to mammalian enzymes)
Describe cell contents
- Soluble cell components (digestible)
- Protein, sugars, & starch
- Glucose (made from photosynthesis) can make starch, cellulose, hemicellulose, or lignin
T/F: The more leaf on the feedstuff the more digestible
True
T/F: As plants get more mature they become more digestible
False they become less digestible
Describe seeds
- High in starch (corn)
- High in fiber b/c of the hull for some plants
How is fiber measured
- Crude fiber
- Neutral detergent fiber (NDF)
- Acid detergent fiber (ADF)
Describe crude fiber
- Not reliable & not very accurate
- Mostly est indigestible portion
Describe NDF
- Solubilizes cell contents
- Leaves hemicellulose, cellulose, & lignin
- Predictor of voluntary intake (provides bulk or fill)
- Lower NDF values are desired
- Increases as forages mature
Describe ADF
- Estimates the most indigestible portion
- Leave cellulose & lignin
- Inversely related to digestibility
- Forages w/ low ADF are higher in energy
What is used as an index of gut fill
NDF
What NDF % will horses not eat
Above 65%
Which fibers are digestible & indigestible in ruminants
- Hemicellulose = most digestible
- Cellulose = mid digestible
- Lignin = indigestible
As lignin increases in ADF what happens to digestibility of cellulose
Decreases
What are non-structural carbs (NSC)
- Soluble component found in the plants cell contents (storage energy)
- Consist of simple sugars (glucose, fructose, sucrose, & lactose), starch, & organic acids
- Digested by endogenous enzymes like amylase
- High in certain hays
- High in grains
- Very impt in horse nutrition
Describe forages (roughages)
- High in structural carbs
- Low in energy
- > 18% crude fiber
- Divided into carbonaceous & proteinaceous (legumes)
What are carbonaceous
- Non-legume forages like grasses
- Ex. timothy grass
What are proteinaceous
- Legumes
- Higher in calcium & protein
- Alfalfa
- Clover
What happens to the nutrient content as forages mature
All nutrients decrease (esp energy & protein) & fiber increases
Describe bermuda grass
- Warm season grass
- Used for lawns, pastures, & hays
- Have a dense root mass & spread through rhizomes (below ground stems) & stolons (above ground stems)
- Becomes very fibrous when it is over matured
Describe ryegrass
- Cool season grass
- High quality
What are the two dx associated w/ perennial ryegrass
- Ryegrass staggers
- Facial eczema
Describe Ryegrass staggers
- fungal endophyte in seed head produces toxins (peramine & lolitrem b)
- can effect horse, cattle, sheep, & llamas
- can recover if removed from the pasture early
Describe facial eczema
- Saprophytic fungus growing on the dead plants produces sporidesmins (mycotoxin)
- Causes photosensitization & skin lesions
Describ annual ryegrass toxicosis w/ annual ryegrass
- Seed head can be infected (yellow slime) by the seed gall nematode, & the nematode is infected by a seed gall bacteria which produces corynetoxin
- Causes brain damage
Describe smooth bromegrass
- Rel winter hardy
- Very common cool season grass
- Grows north into Canada
- No toxic factorsa
What is TE fescue
- Toxic wild endophyte fescue
- Toxic alkaloids
- Causes animal disorders
- Has dev the endophyte to give the plant drought resistance
- Also helps w/ pest resistance
What is EF fescue
- Endophyte free fescue
- No alkaloids
- No drought resistance or pest
- Don’t do well in the south
Describe tall fescue
- Used in lawns & pastures
- Cool season grass but can adapt to warm climates
What is NE fescue
- Novel endophyte
- Strains of endophyte that don’t produce alkaloids
- Do have resistance
What problems are associated w/ TE fescue
- Endophyte produces ergot alkaloids like clavines & lysergic acids
- If animal consumes TE w/ alkaloid the animal can get fescue foot, summer fescue toxicosis,
- mares can have prolonged gestation, weak foals, abortion, agalactia
What do the alkaloids cause
- Vasoconstriction
- Hypersensitivity
- Impaired heat stress recognition
Describe fescue foot
- Gangrene
- In cattle
- Loss of blood flow to the extremities
Describe summer fescue toxicosis
- In cattle
- Elevated body temp
- Rapid breathing
- Poor growth
- Rough hair coat
Describe timothy grass
- Cool season grass
- Doesn’t withstand drought
- Often grown along w/ another grass (ex orchardgrass)
- Impt hay grass & good for horses
Describe orchardgrass
- Very productive, common, cool season grass
- Quality grass hay
- Not drought resistant or hoof resistant
- Usually cut in early bloom or prior to bloom
What can little blue stem have
Feathery seed spikes that can get caught on the animal
Describe orchardgrass
- Very productive, common, cool season grass that makes quality grass hay
- Not as drought resistant or animal hoof resistant as tall fescue
- Usually cut in early bloom or prior to bloom
Describe legumes
- Fix their own nitrogen w/ bacteria assoc w/ their roots
- High mineral content (esp calcium)
- Drought tolerant
- palatable
What are the problems with/ alfalfa
- Bloat in cattle if grazed (highly soluble proteins attacked by slime producing bacteria)
- Blister beetle toxicity in horses
Describe blister beetle toxicity
- From Alfalfa baled in MW, SW, & mountains
- Beetles baled contain cantharidin
- GI irritation & death
- Less toxic in cattle & death
- Oral ulcers & colic
- Check all bales prior to feeding
What are the problems are sweet clover
- High in coumarin which is converted by molds to dicoumarol (a anti-vitamin K & interferes w/ blood clotting)
- Is known as sweet clover dz (affects cattle more, most significant prob is carcass damage from bruising)
Describe problems with red clover
- Rust colored mold on the leaves produces slaframine
- Causes excessive slobbering in horses
What is the problems associated w/ alsike clover
- Alsike clover poisoning
- Unknown toxin
- Acute poisoning - causes photosensitization in horses
- Chronic poisoning - causes liver failure accompanied by neuro impairment in horses
Describe the probles assoc/ white clover
- Can cause bloat
- Contains cyanogenic glycosides that can produce hydrogen cyanide (HCN) - detoxification of HCN in the rumen & liver produces thiocyanate which inhibits binding of iodine in the thyroid gland
What are forbs
- Low growing broadleaf plant that commonly grows w/ grass plants
- Goats are browser & consume many forbs
