Exam 1 Flashcards
Lecture 1
Fiber and Forages
- List the categories of nutrients and state how water, energy and protein are provided
- Identify structural & soluble components of plant cells and describe how these contribute to digestibility
- Explain why DM is an important value to know for feedstuffs
- Define fiber and explain how it is measured
- Explain how NDF and ADF values relate to feed intake & digestibility
- Explain how NDF & ADF are measured
- Describe how nutrient values change with increasing plant maturity
- Classify grasses, summarize their uses, and discuss issues with each species
- Identify issues with each legume species and certain forbs
What are the 5 nutrient categories?
Why is management in large animals important?
What is dry matter vs. as fed basis?
What is water intake based on?
Give an example of high water intake need?
- Water 2. Energy 3. Protein 4. Vitamins 5. Minerals
Water provided as free drinking, fresh always available. consumption based on DMI (dry matter intake).
-Water, energy (fat or lipid and carbohydrate), protein, vitamins, minerals. Energy is not always divided into carbs, lipids, etc.
-Animal management management is based in nutrition
-AS FED when we include water. DRY MATTER does not include water, but it is the most accurate.
-Metabolic water also considered but not as significant
Consumption of water is usually based on Dry matter intake (DMI)
Dairy cattle, lactating
Energy & Protein
Measured in Kcal (1000 cals) or Mcal (1000 Kcal)
What is Total Digestible Nutrients? what are the four parts?
How is protein provided? how is it defined in horses vs. ruminants?
Which one is important to help meet protein need of high-producing dairy cattle?
Energy provided by carbohydrates (starch, hemicellulose, cellulose), lipids (solid fats and oils)
Can be provided by protein if necessary or if protein fed in excess
-Carbohydrates: starch, hemicellulose, cellulose
-Protein: starvation situation, break down of muscles to extract AAs, not a typical situation or if protein fed in excess
-Lipids: Solid fats and oils.
TDN: value calculated as the sum of
- Digestible crude fiber (CF)
- Digestible crude protein (CP)
- Digestible fat multiplied by a factor of 2.25
- Digestible nitrogen free extract (NFE)
-Energy typically measured in Kcal (1000 calories) and Mcal (1000 Kcal) horses Mcal usually.
Protein
-Provides essential (must be provided in diet) an non-essential (does not mean they are not essential to the animal, but can be synthesized by animal) AAs
Horses: CP
Ruminants:
Degradable intake protein
Undegradable intake protein
-Degredable (protein that can be used by microbes to reproduce and make more)
-Undegradable (can pass through the rumen, no degraded by microbes, unchanged and available for digestion by SI)
Undegradable a must for dairy cattle in order to meet the energy requirement
Analysis of Feedstuff
Comparisons of feedstuffs on basis of specific nutrients by a series of heating and chemical extracts the following 5 components ban be determined. Which ones are they?
What do you always do first?
- Determine the DMC, dry the feed.
Important because it reveals the actual amounts of various nutrients available to the animal consuming the feed
- Ash: burned sample to determine minerals (left, don’t burn)
- Energy via bomb calorimeter (gives gross energy)
- Crude protein: measuring nitrogen and multiply by factor of 6.25. Nitrogen values as the average nitrogen content in proteins is 16%
- Fiber: several methods, this lecture
- Non-structural carbohydrates
Fiber
What is it? What are the three discussed components of the plant? Which ones are only digestible by microbes? Which category do proteins, sugars, and starch belong to? How is photosynthesis important in this category?
Give examples of high starch plant structure/component
How is fiber measured and reported? Hint: three ways
Which way is not reliable and not very accurate? Which one is used as a predictor of voluntary intake (bulk fill)?
What does high NDF and ADF values mean? Hint: Low desirable why?
How can DMI be expresses? how can it be estimated?
- Structural component of the plant (cell wall)
Cellulose, hemicellulose and lignin
-Digestible only by microbes bc there is no mammalian enzymes available to do it - Cell contents: within the cell find SOLUBLE cell components, proteins, sugars, starch
Photosynthesis: makes glucose for the plant - Seeds
-High in starch, which is the energy for that seed to become a new plant. Some seeds can be high in fiber protective exterior coat
Corn high starch
How to measure fiber 1. Crude fiber 2. NDF 3. ADF
- Crude fiber: nor a reliable method, not very accurate, not used in large animal nutrition. Estimating indigestible portion. Mostly leaving digestible
- Nutrient detergent fiber: solubilizes cell contents, leaving hemicellulose, cellulose, and lignin content. Used to determine predictor of voluntary intake (bulk or fill). Generally lower NDF values are desired bc means the animal can eat more of the feed, NDF naturally increases as forages matures. Young forage less fiber, mature forage = more fiber = less digestible.
- Acid detergent fiber: leaves cellulose and lignin. The least digestible part of the plant. High values = less digestible, low ADF concentrations usually have higher energy.
NDF first then ADF second
NDF: used as an index of gut fill to predict how much an animal can eat. They typically eat based on their body weight.
Horses
-NDF <40% excellent, but not often found.
Very good hays are usually 40-45%.
>65% horses won’t eat it bc they are picky, cow would eat it.
-Lignin is indigestible, the more lignin present the more it interferes with cellulose (less digestible) (hemicellulose most digestible) digestion
NDF and DMI relationship
-Large animal nutrition try to maximize DMI, small animal just maintenance
DMI is expressed as a percentage of an animals body weight
DMI can be estimated using NDF
-Example: DMI (% BW) = 120/%NDF = estimate for that feed that the animal will eat of dry matter
120/45 = 2.6 % DMI as % BW (dairy cow will produce more, more energy intake)
120/60 = 2% DMI as % BW
ADF and digestibility
-As lignin increases, digestibility of cellulose decreases
-Horses: ADF 30-35% are ideal, but hard to find. >45% less likely to eat it
Non-structural carbohydrates (NSC)
Simple sugars, starch, organic acids
-Non-structural carbohydrates (horses important): soluble component found in the plant’s cell contents.
-Too much can contribute to colic and liminitis
What happens to ADF and NDF as forage matures?
Both increase, high values are undesirable, NDF higher means more fiber, less likely to be eaten. ADF higher means more lignin, less cellulose digestibility, less energy.
Forages (roughages) = High in structural carbohydrates (cellulose)
How are they divided? which one is grasses and which one is legumes?
What are each high in?
What are some differences between alfalfa and grass?
Which grass is associated with:
-Facial eczema, staggers, annual toxicosis
-Gangrene in the extremities, summer toxicosis, mare gestation problems
-No toxicosis
-Very fibrous when mature
-Very good for horses and rabbits, ADF ~35% poor drought resistant, high CP
-Not as productive as others
-Similar to timothy grass
Forage roughages
- Carbonaceous: non legume such as grasses.
- Proteinaceous: They are higher in crude protein usually 15-25% CP ex: alfalfa. They are also higher in calcium
All nutrients decrease (particularly energy and protein and fiber increases as forages mature
Roughage feedstuffs
-Low in energy, high in fiber, high in mineral content. Dairy cattle rations inclusion for rumen health and milk fat content.
Grasses
Bermuda grass
-Warm season grass. Southern. Dense root mass, spreads through rhizomes (underground stems) and stolon. Become very fibrous when over-mature.
Becomes very fibrous when over-mature CP 15-20%, ADF 25-30%, NDF ~55%
Ryegrass
Raygrass staggers, facial eczema, annual ryegrass toxicosis
-Cool season, perennal (comes back every year on its on).
Ryegrass staggers: fungal endophyte in seed head produces toxins. Facial eczema: fungus growing around the base of plant produces spores with toxin = Photosensitization and skin lesions.
-Annual ryegrass toxicosis: (yellow slime) nematode infected by bacteria, which produces the toxin. Incoordination, high stepping gait, brain damage, and death.
Smooth Bromegrass
No toxic factors Grown in Canada
Tall Fescue
Fescue foot, summer fescue toxicosis, mares prolonged gestation weak foals abortion agalactia
-Drought resistant
-Endophyte infected strain (most common) produces ergot alkaloids (ex: ergovaline). Fescue foot: gangrene due to loss of blood to extremities, circulatory ischemia, and Summer Fescue toxicosis: during summer particularly cattle body temperature elevated, rough hair coat, rapid breathing, standing in water.
-Horses: mares pregnant, prolonged gestation, abortion, weak foals, agalactia.
-The problem is the seedhead, the endophyte likes to be there, so when younger and shorter without seed heads, less likely to be a problem. It is same issue whether in bale-dry or fresh grass
Timothy grass
-Cool season, often mixed with other grasses such as orchardgrass
-Great horse hay, rabbit hay
-Relative high CP content
-Poor drought resistant
Orchardgrass
-Similar to timothy
Native grasses
-Not as productive as other species
Legumes
Legumes
What are they high in?
What are some issues with (hints)
-Alfalfa - more toxic to horses or cattle?
-Sweet clover - sweet clover disease
-Red clover - Rust-colored
-Alsike clover - Neurological.. and … failure
-White clover - Thyroid…
-Forbs - Goats like
-Able to fix their own nitrogen from atmosphere bc they have bacteria that allows them to do it
-Soybeans, alfalfa, clovers, green beans, peas, lentils
-Palatable, drought resistant,
High mineral and calcium content
Problems with alfalfa Bloat
-Bloat in cattle due to so much soluble protein, easily digested in rumen, bacteria produces slime.
-Blister beetle toxicity in horses. Midwest hay, beetles in hay contain CANTHARIDIN GI irritant in horses, death, less toxic to sheep and cattle
Sweet clover
High in COUMARIN, which is converted by molds to dicoumarol
-Issue if mold = dicoumaron, antivitamin K interferes with blood clotting.
-Sweet clover disease, cattle more affected than sheep and horses. Carcass damage from bruising
Red clover
-Turns brown after cut into hay due to POLYPHENOL
-Mold Rust colored causes EXCESSIVE SLOBBERING in HORSES
Alsike clover
-Acute poisoning, causes photosensitization
-Chronic poisoning, causes liver failure, neurological impairment in horses
White clover
-Can cause bloat
-Contains cyanogenic glycosides (when the animal chews) that produce HCN, detoxification in rumen and liver produces THIOCYANATE = inhibition of iodine binding in thyroid gland
Frobs
-Goats preferred those
-Examples: Chicory, dandelions.
What forage can cause prolonged gestation and agalactia in mares?
Tall fescue
Lecture 2
- Discuss how pastures should be managed and issues with using pastures
- Describe general moisture levels of silage vs. haylage vs. baleage vs. baled hay
- Summarize factors affecting quality and digestibility of hay
- Discuss nutrient losses that may occur in hay
- Explain how hay can be preserved or treated to improve nutrient value
- Describe how silage is made, especially certain conditions and the necessary properties of the forage
- Describe how the fermentation process occurs in the silo
- Compare differences in major nutrients provided by oilseeds vs. cereal grains
- Describe characteristics and toxic factors/issues associated with oilseeds (whole or meal form) and cereal grains
- List major nutrients provided by by-products and discuss any associated issues
Utilization of forages
What are some methods and reasons for utilization of forages?
What are some essential pasture qualities?
What are three concerns with pastures?
What is the desirable/acceptable moisture level in hayleage, baleage, Green crop, silage? Which one is the lowest, highest moisture?
What factors affect quality and digestibility of hay?
- Pasture: needs to be durable for foot traffic. Major feed for dairy (not always), the most cost effective option, usually. Important to pick a mixture of grasses and legumes
- Hay
- Silage, haylage, baleage
Managing pasture
- Monitor quality/growth
- Use paddocks for rotational grazing: cost to maintain with fence, but increases carrying capacity of the pasture. Mow, fertilize, herbicides, etc.
- Proper stocking rate: varies with type of pasture crop. 1-2 acres per cow, others 10-20 acres.
Pasture concerns
- Poisonous plants: high risk with poorly maintained pastures
- Bloat: legume pasture due to lush plant material (highly soluble nutrients). Best use a mix
- Nitrate poisoning: concern during droughts and if the pasture has been fertilized recently. Can cause abortion or death
Ways to harvest forages
-Green chop: fresh harvest immediately out of the field high water content >80%
-Silage: ~70% moisture
-Haylage: ~40-60% moisture
-Baleage: round bale silage = 50-60% moisture. Stored in sealed plastic wrap
-Hay: baled at 15-20% moisture
Mold is the enemy of hay and silage
Storage of roughages
-Preserved long fibers: hay (long fiber) or haylage/bayleage SEMI-WILTED, FERMENTED = haulage/hayleage
-Preserved short fibers: Silages higher moisture than haylage
Hay Harvesting
Moisture must be < 15-20% otherwise fire hazard
-Stage of maturity, nutritional value decreases quickly, less yield.
Hay losses, Preservatives and Additives
Which (one each) causes nutrient, energy, vitamin A, CP, and Total digestible nutrients content losses?
What are three common additives in hay making? how do they help?
Bovine bonkers is associated with what additive?
How does dried and processed hay compared to additives?
-Leaf shatter: normal, but can be as high as 40-70%
-Heat damage: moisture >25-30% = MOLD and HEAT Above 120F = nutrient loss, protein binding irreversible, carbs unavailable
-Spontaneous combustion
-Fermentation losses: sugars and starches converted to CO2 and water = REDUCED ENERGY
-Bleaching: stored hay loses vitamin A (if stored out of the sun, remains green)
-CP and TND reduction: normal condition and storage overall
highest risk if >20% moisture, within 7 days it will ignite
Preservatives and Additives
-Preservatives: propionic acid, formic acid. Allows storage at higher moisture level. Antifungals
-Anhydrous ammonia: treatment for low quality hay (such as very mature) to improve protein and energy content. Increases digestibility by dissolving lignin. Can cause Bovine Bonkers = reaction between ammonia and sugars in the hay, can cause toxins, incoordination, tremors.
Dried and processed hay
-Cubes and pellets
-Alfalfa, grasses
-Ground and dried
-Higher quality, more consistent, more expensive
Silage, Haylage, Bealage
How is silage preserved, package, and quality indicator is?
What is inhibited by lack of oxygen during processing?
Silage:
-Entire plant chopped into small pieces
Preserving by controlled fermentation in a high moisture content
Exhaust the oxygen, fermentation of sugars to organic acids, primarily lactic acid
-Named according to the plant of origin: ex corn silage.
Fermentation and anaerobic conditions a must, lactic acid is the energy for the animal, MOLD is INHIBITED
-Lactic acid = reduced pH = prevents bacterial growth as long as there is no oxygen. Listeria and botulism risk if pH rises. Carmelization if >100-120F
50-70% moisture range is the target
Storage
-Silos, piles, bags, etc.
-Proper packaging: cut at proper length, weight important.
-Penn State Forage Particle Separator: separated components based on particle size. Indicator of quality, as particle size determines rate of fermentation, digestibility of silage, and rumination.
Soybean meal is the most common supplement fed to what species?
How are concentrate feeds classified? Which are high in protein and which in energy?
What is “MEAL”?
What are some toxic factors associated with soybean, cottonseed?
Grain cereal, explain some benefits and issues
Grain by-products
List major nutrients and discuss issues if any. Which one is a good energy source for horses?
Stem and leaves of oilseeds and cereal grains are roughages
-Soybean fed to swine and poultry
- Oilseeds - provide protein
-Corn, sunflower, canola, flaxseed.
-High in protein: Cottonseed and Soybean
Toxic factors
-Soybean: contains trypsin inhibitors = decreased protein digestibility. Also contains storage proteins that cause allergic reactions, and lectins (bind carbs in intestine), and phytoestrogens (mimic estrogen)
-Cottonseed: Risk of gossypol toxicity when whole cottonseed is fed. Toxic yellow compound affects the lungs, heart, and reproductive organs. More harmful in young than mature ruminants (rumen detoxifies).
Heat-treated and processing can inactivate both
-Rapeseed: High in Glucosinolates = inhibit thyroid metabolism and can induce goiter
-Canola: Low in glucosinolates, deficient in some AA.
- Cereal grains - provide energy
-Barley, oats, corn.
-High in starch, generally high in phosphorus, digestible energy.
-Corn is the gold standard regarding level of energy
MEAL: the remaining residue after oil extraction, which is high in protein
Issues with corn
-Low CP. lysine, and tryptophan (true to all cereal grains)
-Less digestible when hole, needs processing to be utilized by animal
Contamination mycotoxins produced by molds- Aflatoxin
Issues with Sorghum (milo)
-Needs processing too
-Tannins in outer layer react with enzymes in GIT to reduced digestibility - must heat-treat
Issues with Wheat
-Risk of acidosis in cattle because it is highly fermentable starch limit to 50% of grain intake in cattle
Oats
-Typically fed to horses
-High quality CP, less DE, more soluble fiber = less colic
Barley
-Drought resistant
-Can be fed to ruminants
-Lower energy than corn
Grain by-products
Brewer’s and distiller’s grains
-Good: can be fed wet or dry, good protein source bc starch is consumed while protein is left during fermentation
-Bad: none given maybe the fact that it has to be limited intake for ruminants?
Beet pulp
-Good: Palatable, soluble fiber, Good energy source particularly for horses.
-Bad: none given
Molasses
-Good: Reduce dust, binding agent. Palatable, can feed with non-protein nitrogen source (urea), minerals and roughage for proper rumen function
Others
-Meat and bone meal: Can not be fed to ruminants BSE risk.
-Poultry litter: high in non-protein nitrogen
-Blood meal: high in protein
-Restaurant food waste
Oils and Fats
-Reduce dust
-High DE
Lecture 3
- Describe common problems associated with high grain diets
- Discuss disorders associated with common grasses and legumes fed to horses
- Describe how NSC and fructans relate to laminitis and how to manage a horse with laminitis
- Describe the cause of fescue toxicosis and symptoms in horses
- Discuss predisposing factors for cribbing and gastric ulcers and how to treat/prevent each disorder
- Describe problems with feeding hay to horses with heaves 7. Describe choke and moldy corn disease
Body Condition Scoring in Horses
What are the ideal ranges according to their use?
How many pounds about does each over conditioned score translate to?
1 to 9 scale
4-6 ideal range
It depends on what their job is, may need to be more on the lean side or not.
Each body condition score = ~50lbs
ex if they are an 8 score, they are about 100 lbs overweight
Poor: 1-3
Moderate: 4-6
Fat: 7-9 susceptible to equine metabolic syndrome, insulin resistant, laminitis
Performance horses
-Around 4-5 score ideal
Pleasure horses: 5-6 ideal
Areas to asses in the horse
-Crest
-Withers
-Behind the shoulder
-Along the back
-Tailhead region
-Over the ribs
Equine Digestion review
Where does most proteins/AAs get digested? Where do high quality and poor protein (what is high quality protein?) get digested?
-Selective grazers: picky, can clip grass close to the ground. Grind with molars.
-Small stomach: frequent meals, no gallbladder (bile flows constantly if eating continuously)
-Non-ruminant herbivore, most digestion in small intestine, fermentation in cecum and large intestine.
Mammals have Amylase enzyme to digest starch
-Horses have microbes in hindgut to digest hemicellulose, cellulose, lignin.
Small intestine
-Proteins absorbed as AAs
-Quality varies with the protein source (refers to the amino acid profile, is it going to contain a lot of essential AAs that are required in the diet?)
-High quality protein more digested and absorbed. Mixed feed up to 55% of protein that gets digested in SI
-low quality protein gets digested in the hindgut
-Ruminants: microbes take care of essential AAs, don’t have to have it in diet.
-Horses: we do worry about protein quality
Carbohydrates
-Starch and others digested in SI
-Hydrolyzed/digestible carbohydrates, such as starch
Surgery where 50% SI removed, problems occur
Carbohydrate terms (CHO)
In which category do some oligosaccharides (fructans) and resistant starches fall into? Where are they digested? Is there a problem associated with them, why?
-NSC: non-structural carbohydrates that are digestible, simple sugars, starch, fructans.
-Structural carbohydrates: cellulose, hemicellulose, lignin
-Hydrolyzable: simple sugars, non-resistant starches
-Rapidly fermentable: Resistant starches, oligossacharides (short chain of carbohydrates, ex: fructans). Microbial digestion in large intestine. Too much of this can cause problems due to rapid fermentation resistant starches carbohydrates
-Slowly fermentable CHO: Hemicellulose and cellulose, takes a long time to ferment them.
Equine LI digestion
How long does it take for feed to make it to LI?
What is the VFAs produced?
-Primary site of water absorption
Feed from a single meal can appear in LI within 2 hrs
-Digestion in LI results in microbial fermentation (breakdown of structural carbohydrates, cellulose, hemicellulose)
Product
VFAs
-Acetate
-Butyrate
-Propionate
Pasture for horses
Is pasture alone always nutritionally sufficient for bred or lactating mares?
Ideal to have multiple pastures and use pasture rotation, which helps with parasite control and prevents over-grazing
What is an ideal pasture for horses?
-Ideal pasture is a mixture of grasses and legumes
-Lactating mares, horses in training have higher energy demands not usually met with pasture alone. Grain supplementation
-It is common to batch feed horses which leads to feces to be dry. The natural way for horses is pasture all day long
-If they are in a good pasture they can get their nutritional needs met within 4 hours.
-Rotational pasture is ideal
-Kentucky blue grass preferable to taller grasses.
-Endophyte free fescue, timothy are ok grasses.
-Ideal 4-8 inches tall grass, not forming seed heads. They don’t like seed head grass.
Adequate pasture
-Nutrient analysis: grass sample and soil sample.
-Is digestible energy sufficient, are nutrients present in correct rations? One reason for fertilizer
1. Get nutritional analysis
2. Feed by weight
Characteristics of good equine hay
-Low stemminess
-Lots of leafiness
-Green color (brown means loss of vitamin A)
-Free from mold and dust
-Smells good/fresh
-No foreign material weeds, poisonous plants.
“horse hay vs. cow hay”
Equine dry matter intake
Maintenance : 1.5 to 2% of BW
3% BW peak lactation
2 to 3.5% of BW in growing horses
Example: 950 lb horse at 1.5% of BW per day (950 x 0.015) = 14.25 lbs DM/day
Feeding Grain
-Usually fed in pan or ground
-Need to weigh and not rely on volume
Storage
-Important due to access of wildlife to feed, opossums can transmit diseases
-Weather protected
-Off the gound, prevent
Texture feeds
-Often molasses added to increase palatability and reduce dust. “Sweet feed”
Pelleted feeds
-Ideal bc they are uniform, they can’t sort it. Less mold formation, but possibility of choke
Lactating mares
-Feed 2-3 times a day
-At least 1 or more extra bowls
Lecture 4
- Describe common problems associated with high grain diets
- Discuss disorders associated with common grasses and legumes fed to horses
- Describe how NSC and fructans relate to laminitis and how to manage a horse with laminitis
- Describe the cause of fescue toxicosis and symptoms in horses
- Discuss predisposing factors for cribbing and gastric ulcers and how to treat/prevent each disorder
- Describe problems with feeding hay to horses with heaves 7. Describe choke and moldy corn disease
High concentration diets in horses
What are some problems that can happen when horse if fed too much concentrate diets?
** The dry matter of BW per day intake, only tells me the limit of DM intake, not nutritional needs or meet energy requirement **
-Delivery too much starch to LI, overeating on grain. High starch fermentation may lead to: diarrhea, colic, and laminitis.
-Guideline of limitations: 5.5 lbs per 1100lbs of BW, at least 50% of hay, not lower than 40%.
-Fermentation causes decrease pH, creation of Volatile fatty acids, so lower pH.
-Changes to cecal pH: more gram (-) bacteria dies. Changes in bacterial population can result in endotoxin release that cause mucosal damage. It can result in SHOCK due to inflammatory mediators released. Treated as emergency
Problems with Bermuda Grass and Endophyte-infected tall fescue
Which grass is associated with ileal compaction and colic?
Bermuda Grass
-Can rapidly become fibrous and cause impaction colic. Coastal bermuda can cause ileal impactions in horses. Resulting in Strong Contractions that squeezes water content out, theory.
Fescue grass
-Can be endophyte-infected
-Poor growth
-Prolonged gestation in mares, thickened placenta, agalactia, increased foal mortality
Clovers
-Alsike clover: linked to developmental liver disease, neurological signs, photosensitization
-Red clover: extreme slobbering produced. Slaframine toxin.
Laminitis, Rapid fermentation of NSC
-Many possible causes
-Sugars, fructans, and starch (soluble, non-structural carbohydrates) where they are rapidly fermented.
Excessive NSC in LI
-Overgrowth of bacteria that digests starch and fructans. Lactid acid produced during fermentation, acidic environment, inflammation of gut wall, diarrhea, colic. Damaged to the wall allows endotoxins of bacteria to injury the gut and absorption of toxins, endotoxins = laminitis.
-NSC: non-structural carbs
-WSC: water soluble carbs, oligosaccharides, some polysaccharides, frunctans and pectins
-ESC: ethanol soluble carbohydrates, particularly sugars, glucose, sucrose, fructose. Value should be low
Ex: WSC - ESC = rough estimate of fructans.
NSC = WSC + Starch
WSC = ESC + Fructans
Fructans: accumulate when rate of photosynthesis exceeds use of energy in plants, such as when there is cool weather, late in the day, drought, after a frost. Typically highest levels in late spring grasses.
Fructans
What is the storage carbohydrate in growing grasses? Why is it dangerous for horses? what conditions lead to high accumulation of it in the plant?
How can you avoid pasture associated laments?
-They are oligosaccharides (short chains of fructose)
-Storage carb in growing grasses
-Fructans accumulate when rate of photosynthesis exceeds use of energy for growth in plants.
Cool weather, after a frost, drought, late in the day: periods of accumulation highest in grasses
-Why are fructans dangerous? not digested by mammalian enzymes, can’t digest the chains in the SI and end up in the large intestine.
Experimentally laminitis induced: starch 18g/kg DM , fructans 10g/kg
pasture can accumulate > 400 g fructans/kg DM
Avoiding Pasture-associated Laminitis
-NSC content of hay can be reduced by ~30% by soaking in water for 30- 60 minutes
-Restrict grazing, especially in spring
-Supplement with hay made from mature grasses
-Analyze grasses for NSC
NSC above 12% may contribute to issues
Cribbing (wind sucking, aerophagia)
Predisposing factors
-Stall weaning vs. pasture weaning
-Stall housing following weaning
-Feeding concentrates
-Lack of time at pasture
-Lack of straw bedding in stall
Treatment
-Increase dietary fiber, remove ledges, electric fece, creosote, dog collar, cribbing collar, surgery, etc. Miracle collar used frequently Cribbing muzzle
Gastric Ulcers
-Most common in performance horses
-Non-glandular stratified squamous mucosa
Risk factors
-Intense exercise
-Increased stall time
-Meal feeding
-Not having hay available and at libitum
Treatment
-Feeding alfalfa can be protective. Protein and calcium buffer gastric pH.
-Feeding aloe vera, corn oil, antacids.
-Roughage stimulates saliva = buffer rich in bicarbonate
-Gastroguard, Ulcergard, Omeprazole
-Avoid dusty, moldy hay.
-Feed cubes
-Soak hay: 30% reduction in sugar content, 50% reduction in potassium (also done for laminitis)
-Steam, sterilized the hay
Vitamin E deficiency = Equine lower motor neuron disease. Equine degenerative Myeloencephalopathy
Moldy Corn
-Leukoencephalomalacia
-Fumonisins toxicity (mycotoxin) causes neurological signs
-Liquefactive necrosis of the cerebral WM
Choke
-Happend with pellets more often
-Food gets stuck in esophagus
-Nasal discharge
-Bad teeth
Lecture 5 Equine Nutrition
- List sources of nutrient requirement information
- Discuss average maintenance energy requirements and calculate increased energy requirements for lactation and work
- Discuss the average CP% requirements for horses in various physiological states 4. Explain when it may be appropriate to supplement fat in a diet
- Describe general guidelines for water provision
- Explain how to safely manage/increase the diet of a starving horse
- Discuss potential problems with geriatric horses and possible diet adjustments 8. Describe how the metabolism of horses and ponies differs
- Describe how the diet of an obese horse should be managed and how to safely reduce feed intake in the obese horses and strategies for management
- Discuss the causes and results of DOD and contracted tendons in growing horses
- Discuss how diet should be managed in horses susceptible to recurrent exertional rhabdomyolysis
- List and describe examples of supplements/nutraceuticals for reproduction, hoof health, DJD, inflammation, etc.
Resources for nutrient requirement of horses
1. National Research Council: represents minimum requirements
2. Equine-analytical website: type of horse, age, current BW and BCS. Physiological state
Energy flow diagram
For horses it is calculated as Digestible Energy (DE)
- Bomb calorimeter
- Gross energy (GE)
- Digestible energy (DE): accounting for fecal energy losses
- Metabolized energy (ME): Dogs, cats, cattle (beef) accounts for gases and urinary energy losses
- Net energy (NE): diary cattle, it accounts for the three major energy losses, including heat loss. It is the most accurate energy measurement
-NEm: net energy for maintenance
-NEp: net energy for production (dairy cattle, lactation, pregnancy needs)
Protein requirements of Horses, Calcium, Phosphorus, Dietary fat
CP for Maintenance, pregnant mares, lactating mares, weanlings are?
-Lysine: important bc tends to be one of the most limiting in a lot of the feed, not as much as needed in most feeds.
-Protein quality less critical in mature horse at maintenance: essential ammino acids. Ideal profile important for growth
-Maintanence: 8% CP
-Pregnant mares: 10% during last trimester
-Lactating mares: 13% first 3 months, 11% 3 months to weaning
-Weanlings: 14%
Deficiencies
Young animals: affected growth
Mature animals: body condition loss, poor hoof growth and coat, won’t thrive.
Calcium and phosphorus requirements
Maintenance:
Lactation:
Growth: highest
Dietary fat
-Endurance horses burn fat: 25-100 km over 1-2 days
Feeding trials show benefits of adding fat to diet of endurance horses
-Reduce risk of grain overload as fat replaces some of the grain
Supplemental fat
-Must acclimate horses to higher levels of fat
-May improve coat sheen
Basal hay:grain diets are about 3% fat
-Can include up tp 10% of fat in diet
-Sources: corn oil, say oil, rice bran.
Water
-1000lbs horse = ~8-10 gallons per day for maintenance
-Warm water in cold weather will increase intake 3x, prevents impaction.
Guidelines
Lactation increases need by 50-80%
Exercice increases need by 20-400%
Prevents impaction
- Provide free access to palatable water. Cool water preferred except in winter
- During exercise allow horse to drink as often as possible
- Provide salt to encourage adequate water consumption
Clinical Nutrition
- Managing starvation
-Start on poor to moderate quality grass or oat hay to start GI tract working well again.
-Introduce at 50% of maintenance (based on BW) and gradually increase to maintenance level over 10 days.
-As horse starves there is less production of digestive enzymes, so don’t start feeding them like a normal horse.
Reduce nutrient drains such as parasites
- Managing general dietary changes for a starving horse or reintroduced after colic. Applies to healthy horses too.
-Grain: Add 1/4 of full amount every 2-3 days (then half), to achieve 10 day minimum
-Start at 1/4, 1/2, 3/4 full
-Make sure it is not more than 1lb per day of concentrate
-Laminitis and colic can occur from sudden dietary changes
- Nutritional management of geriatric horses
BCS <4 do better on what?
-About 70% of geriatric horses have age-associated issues
-Potential problems
-PPID: lose of dopamine inhibition of ACTH release
-Poor dentition
-Arthritis
-BCS < 4: PRASCEND Dietary management = pelleted senior feeds, fat supplementation, limit grain and pasture with high fructans. Feed 2-4 times a day
Pony and Horse Metabolism Not the same
What can happen if a pony is fasted? what is the treatment?
Pony
-Increased lipolysis from adipose tissue in response to decreased insulin and negative energy balance
-Much more susceptible to hyperlipemia if fasted. Treatment = IV glucose and amino acids, but nutritional management is best Start about 50% of maintenance
-Leads to fatty infiltration of liver, overall high TG
Hyperlipemia treatment
-Nutritional management is best, but insulin may help
-Force feeding (if nor willing)
Nutritional problems in growing horses
What are some issues that can happen and causes?
-Developmental orthopedic disease: Bone cysts, valves, various, OCD, physitis
-Too much grain/energy, overfeeding
-Improper amounts of minerals, calcium, phosphorus, copper, zinc.
Requirements
-Calcium 0.8-1.5 %
-Phosphorus 0.4-0.6%
-Exercise strengthens bones
Dietary management of obese horses
-3 to 4 weeks to safely reduce feed/grain intake
Not below 50% of maintenance, first at current body weight, then for ideal body weight
Strategy
-Feed 2% of current body weight for 2 weeks, then 1.5% of current BW for 2 weeks, then 1.5% of target body weight for 2 weeks
-Feed a poor quality hay, but ration must be balanced
Management
-Grazing muzzle
-Limit pasture access
-Thyroid hormone: levothyroxine, feed 3x normal dosage. Weaned off once weight loss occurs
Exertional Myopathy
Syndrome of muscle fatigue (not on objectives)
Lecture 7
- State how much dry matter a dairy cow eats during peak lactation
- Describe the different types of milking systems and milking parlors and advantages of each type
- Describe the reproduction benchmarks for dairy cows and factors affecting peak milk production
- Explain the types of dairy production systems
- Discuss different feeding systems for confinement dairies
- Discuss the advantages/disadvantages of feeding a TMR vs. component feeding
- Explain the guidelines for inclusion of grain, NDF, protein, and fat in the diet of an early lactation cow
- Explain how to body condition score a dairy cow
Holstein Cow - Metabolic athlete
How much can a cow eat DM and AF during peak lactation?
~1350 lbs
Consumes ~50 lbs DM per day (3.7% of BW) in peak lactation
-Consumes ~100 lbs of food AF/day
-Peak milk production ~100-140 lbs/day
-TMR: total mixed ratio, the most common way to feed cows. It can be corn silage, hay, soybean meal, other byproducts feeds, vitamins, and minerals. Mixing it well and completely is very important.
Types of milking systems
Portable milkers
-Usually less than 20 cows
Barn milking system
-Used if cows are tied in a barn. One milking station per two cows.
Milking Parlors
- Herringbone: milking machines in the middle, two rows of cows on each side. Central pit for workers to be in. Setup at a slant, udders toward the pit and workers can clean udders and connect the milker
- SwingOver: very similar to herringbone, but only one set of milkers
- Rapid exits parallel: building can be short
- Rotary:
- Robotic
Typical life of a dairy cow
At what age are heifers freshen?
How many days does a cow spend pregnant?
How many days of dry period?
Lactates until what day?
When about is peak lactation?
-Day 0: the day that she calfs (gives birth)
-First calf heifer: usually 2 years of age
-Days 0-120: Open (non-pregnant)
-Days 120-400 (280 d) pregnant, lactates until day 340. Dry off for about 60 days
-Dry period: 60 days
-Usually removed from the herd after 3-5 lactations
-Days open: time from calving until conception
Goal is to have 75% cows bred by 150 days in milk (DIM)
-Heat detection rate (HDR): main way via artificial insemination
-Pregnancy rate (PR)
-HDR + PR affect calving interval and days open
-Calving interval ideal: ~400 days or 13.2 months
-Days open: time from calving until conception. Average ~166 days. Goal is to have 75% cows bred by 150 days in milk (DIM)
-Waiting period: ideal 45-60, commonly 90-100 days
-AI services per conception is usually 2
Lactation Curve
-Lactation ends about day 340
-Peak milk production usually between 30-150 days DIM. Affected by breed, nutrition, season of the year.
-High production animals peak later in the lactation curve compared to lower-producing animals.
Dairy production system
Confinement dairies
-Stanchion barns
-Free stall + parlor
-Dry lot parlor
-Compost-bedeed pack barn (since 2001, new) + parlor
Pasture based systems
-Intensive grazing: graze 6-7 mts/year confinement for 5-6 mts. Feed savings
-Intensive grazing and seasonal breeding: challenge is variation in forage quality. When cows are in peak lactation they graze, with the goal of decreasing feed cost.
-Permanent pasture and supplemental feeding: focus breeding into 2-3 so calves
Milk is highly variable due to changing forage quality
Confinement dairy feeding systems
What are the challenges? What are the benefits of feeding forage before grain? What is the maximum percentage ration of grains in total mixed ration (TMR)?
What is the ideal balance?
What are advantages of TMR?
-Hay and grain: concentrates (grains) should always be limited to more than 60% of the ration. Issues: consuming enough nutrients depends on the cow eating enough of both.
Hay alone does not provide adequate energy requirements, they need more
-Component feeding: corn silage, grain mix,
-Total mixed ration (TMR)
Component feeding
-Feed and forage before grain, feed hay first
-Feed forage 30 minutes - 1.5 hours before offering grain. Benefits includes buffering of the rumen before producing a lot of acid from gain mixture.
-Ideally, a balance of rapidly + slowly fermentable carbohydrate sources
-Ideally some protein from soybean meal or distillers grain
TMR
-Probably the most common
-Tends to reduce sorting of feed
-Cows fed TMR tend to produce more milk
Feeding Dairy Cows
No less than 30% of____?
What is scratch factor? height?
-DMI is limiting factor: hight producing cows unable to meet energy requirements in early lactation from diet alone. Dry matter intake.
-NDF no less than 30%, most should come from forage. Physically effective NDF = scratch factor ~2 inches or longer to stimulate the rumen to chew cot and produce buffer.
-Protein - need rumen degradable and undegradable protein.
Lecture 8 Dairy Nutrition 2
- List and discuss the factors influencing and regulating DMI in dairy cows
- Summarize how cows budget their time each day; discuss the significance of deviations from this normal schedule
- Discuss the implications of competition at the feed bunk
- List the major VFAs produced in the rumen and state how they are used in energy metabolism
- Define subacute rumen acidosis and discuss factors that contribute to its development
- Discuss how ambient temperature affects rumen pH
- Define net energy
- List the minimum requirements for ADF, NDF, forage NDF and NFC in early lactation cow rations
- Discuss the guidelines for inclusion of fat and protein in dairy cow rations
Dairy Nutrition Goals
Preserve rumen health
What is a transition cow? what is the transition period?
-Maximize energy intake: needs for high production = 5x maintenance
-Maximize dry matter
-Need rapidly fermenting , but they lower pH, to protect rumen health you make sure there is enough forage in diet to provide enough buffering.
-The transitioning cow is a cow that is three weeks prior to three weeks after calving. That is when she is transitioning to her milk production. Time when grain in her diet is being adjusted.
-Transition needs to be slow, can risk acidosis
DMI
-Expressed as percentage of body weight
-Beef maintenance = ~2% DMI of BW
-Lactating dairy cow ~3.5-4.5% DMI
-1350 lbs dairy cow at 3.7% DMI = 50 lbs DM/day
-Influenced by stage of lacation, cows consume feed to meet energy needs, so intake is driven by milk production
-Digestibility of fiber in diet
-Environmental conditions
Regulation of DMI
-Rumen fill is going to regulate water intake, DMI, different in different classes of animals
-Affected by level of production
-Affected by energy content of the feed, highly digestible = high energy = intake increases due to palatability
DMI (%BW) = 120/NDF
Cow time management each day
How many hours does a cow spend eating each day? drinking? ruminating? resting at least?
Top 10% of herd spends how many hours resting?
-3-5 hours eating per day, 9-14 meals.
-48,080 chews (10% of energy use)
-30 minutes drinking
-At least 7-10 hours ruminating
-Needs at least 10 hours of lying/resting
-2-3 hours milking
How do the top 10% of the heard differ? 14.1 hrs resting
-Amount of resting time is greater than the average
-Laying down reduces time on their feet, and helps increase blood flow to the udder, also ruminating more which contributes to eating more.
-Most cows are laying down and standing more than 60 times per day
-They might now like the surface of the ground, may be uncomfortable and lay in the alley.
Competition at the feed bunk
-Space should allow 70% of cows to eat at one time
-18-30 inches
-For every additional 1 lb of DM eaten, 2.5-3 lbs of milk more produced.
Nutrients for dairy cows
What is the main glucose precursor? hint: Precursor - P
What are the VFAs? Percentages in rumen production? Hint: APB. Which one is the precursor for fat and milk hint: Adipose - A. Which one is precursor for B-hydroxybutyrate?
Rumen Health
How much forage cows need minimum? What do they provide and how much of it is needed?
What is SARA? what is normal rumen pH and units of change normally? What happens to rumen health when temperature are high?
Protein metabolism
Soluble Intake Protein (SIP)
Non-protein nitrogen (NPN)
Natural protein
Degradable intake protein (DIP)
Undegradable Intake Protein (UIP)
Metabolizable Protein (MO)
Rumen Digestible Protein (RDP)
-Energy sources
-Protein
-Minerals, Ca, P, Mg especially
-Fiber and length (~2inches) to stimulate rumination.
-Water
-Vitamins
Energy sources for dairy cows
-Forages - structural carbohydrates (SC) - cell walls. Lignin, cellulose, hemicellulose, pectins.
-Non-structural carbohydrates (NSC)
-Non-fiber carbohydrates (NFC) includes NSC + more of the soluble fiber sources
Energy metabolism
Rumen production of VFAs
-Acetate: 65%
-Propionate goes up if there is more grain in the diet 25%
-Butyrate 10%
Ruminants constant production of glucose, constant gluconeognenesis
Other between meals liver release and store glucose, gluconeogenesis between meals
-Propionate is the main glucose precursor
-Acetate mainly coming from structural carbohydrates main procursor for fat (adipose and milk)
Flow of dietary Energy
NEm: net energy for maintenance
NEL: net energy for lactation
Rumen Health
-Need 15-20% of forage
-Provides effective NDF (eNDF) needed 22% at least
Early lactating cows
-NDF from forage 20-24% (DM basis)
-ADF 18%
-NFC 37-42%
Dry cows
-NDF 35%
-ADF 28%
-NDF from forage 25%
-NFC 20-30%
Subacute Rumen Acidosis (SARA)
-Insufficient eNDF reduces salivary production of buffer = lower pH
-Transition cows at high risk
-High grain diets lead to excessive VFAs production, can exceed the absorptive ability of the rumen papillae, lowering pH.
-Normal rumen pH fluctuates 0.5-1 pH units within a 24 hr period
-If below 5.5 pH, DMI will decrease - protective mechanism
-Very low rumen pH can lead to damage of rumen wall, bacteria enter blood.
Ambient temperature and rumen pH
-Dairy cattle can’t dissipate heal efficiently
-Lots of human fermentation produces a lot of heat
-High temp = high stress
-Reduced intake, panting, drooling
Protein Metabolism
SIP: means readily available nitrogen for microbes (urea is a source)
DIP: can be 60-65% of total protein intake
DIP/RDP: contains true proteins = more slowly digested in rumen/available to microbes over longer time period
[UIP/RDP]/by-pass protein: can be 35-40%
Must carefully balance dietary CHO and RDP because microbial protein synthesis requires energy
COWS UTILIZE MICROBIAL PROTEIN for about 50% of PROTEIN REQUIREMENT
-CP 16-18% dairy
-CP 12% dry cows
Fat in Dairy Rations
-If NFC (non fiber carbs) is high, substitute corn for fat ok
-Based om 3% rations
-Maximun fat in ration is 7%
-Fat in rumen is undegredable, so reduces available CHO for microbial protein synthesis
Lecture 9 Dairy Nutrition 3
Protein Nutrition
-Amino acid balance: Lysine and methionine limiting most feeds
-Soybean meal, dried brewers grain, blood or fish meal may provide extra lysine and methionine
-Rumen-protected AA may be fed
-Molasses will be rapidly fermented in rumen
Issues in protein - environmental
-Exceeding the protein requirement for any animal, the nitrogen will be excreted into the environment. It is a waste of money and bad for the environment.
12-18% protein, nitrogen excretion increases from 99-228 g/day
Need to match carbohydrate and protein fermentation to maximize N utilization by bacteria
Milk fever
Metabolic alkalosis and acidosis physiology. **Metabolic alkalosis
Potassium can get exchange in cells for hydrogens
High dietary potassium we can have an issue with inducing metabolic alkalosis. Potassium added into plasma, decrease hydrogen in cells = increased hydroxyl ions to maintain electroneutrality.
Metabolic alkalosis affects thyroid hormone receptor and alters homeostasis, calcium and vitamin D homeostasis disturbed.
Lecture 10 Dairy Calf Nutrition
Health of the Newborn
-Calves are taken aways from the cow right away
-They have a very naive immune system
-Born into a contaminated environment: important to keep them as clean as possible
*Get colostrum into them asap
-Thermoregulartion difficult
-They are at risk for Hypoglycemia/starvation. They are born without much fat and muscle tone is minimal. They can’t do much to generate body heal
Control of disease
-Adequate colostrum
-Clean environment
-Protection against rapid heat loss
-Caretakers should have clean hands
Immediate care
-Dry the calf
-Dip navel in iodine solution
-Separate calf from cow (dairy)
-Hand-feed high quality colostrum
-Beef are moved to nursing pasture
Ideal to give colostrum within 6 hours from birth
-Milk the cow for colostrum within 4 hours
-Ability to absorb immunoglobulins begins to fall immediately after birth
-By 6 hours after birth, absorption ability has decreased by 30%
-By 8 hours, reduced absorption by 50%
-By 24 hours reduced absorption is reduced nearly completely
-Milk or milk replaces until about 6 weeks of age
-Weaning onto solid food
What is colostrum?
-Only the first one is the highest quality
-After the first milking the milk is called “transitional” into regular milk
-Colostrum is double the DM content of milk (including protein)
-Antibody-rich: IgG - the largest antibody component in cow milk, very important in prevention of septicemia. IgA, IgM, IgG.
Measure antibodies
-Colostrometer
-Adequate of IgG leven in colostrum is 20-100 mg/ml
-Needs at least 50 mg/ml or higher to be considered high quality
-Measure specific gravity
Colostrum
-Failure of passive transfer
-Total plasma protein levels test (refractometer or IgG Assay) should be 5.5 g/dl or greater.
Colostrum feeding to calves
-Hand feed dairy calves
1. Feed full amount by esophageal feeder ASAP
2. Feed full amount within first 6 hours
3. Feed half to 2/3 amount within first two hours and remained non later than 13 hours.
Colostrum feeding to calves and Colostrum failure
-Amount depends on breed and genetics
-50-100 lbs, feed 3 quarts
-<50 lbs, feed 2 quarts
->100 lbs feed 4 quarts
**Serum IgG critical level >0.8 g/dl **
Risk factors for newborns
-Cow leaking colostrum
-First time heifer calf, less quality colostrum
-Rearing in groups of 7 or more
-Premature birth
Adequate immunity
-Depends on adequate nutrition
-Heifers produce less volume with lower IgG concentrations than cows
-High volume does not always equal high quality colostrum
-Usually true that high quality colostrum is thick and creamy
-High producing cows tend to produce dilute colostrum: the volume is very high so the IgG levels are being diluted
**Need >60 g/l or 0.6 g/dl concentration to be sufficient antibody within constraints of normal intake for calf
Colostrum Substitutes
-Frozen
-Commercial products
Must be from BLV-negative and Johne’s negative cows
Replacers, NOT supplements
Lecture 11 Beef Nutrition
Compared beef cattle to dairy cattle
-Beef cattle are NOT “factories” (dairy) but “scavengers” bc they are out in the pasture all the time. Their nutrition comes from the pasture primarily
Types of operations
- Cow-calf operations: heifers and bulls born (castrated to steers), heifers are kept for replacement cows, usually. Bull calves sold at weaning
-Large : 200 or more
-Medium: 50 to 199
-Small: 1-49
- Background and stocker operations: weened calves kept on dry-lots and fed roughage and grain
-Stocker: weaned calves that are grazing with some grain supplementation.
Goal is the same, we want to grow to a weight to enter a feedlot - Finishing operations: grow to a finish weight for slaughter. High grain diet. Feedlots.
There is still a lot of beef cattle small (>100 cows) operations
-Most have a permanent herd of cows
-May or may not have a bull
-Using land suitable for pasture and hay, main source of nutrition
-About 2/3 of calves sold at weaning, “feeder calves” they can go to an auction or specialized sells.
Technology utilization in cow/calf operations
-Large operations tend to utilize more technology
-Palpation and semen evaluation are two of the most utilized reproductive technologies.
-Embryo transferred is the least used
Goals of cow-calf operations
- Maintain reproductive efficiency
- Minimize morbidity and mortality
- Keep cows cheaply over the winter
Average weights
-Mature angus cow 1000-1300 lbs
-Newborn calves 65-100 lbs
-Weaning weight (6mts) 500 lbs (can vary depending on age, some people wean at different ages, early = less weight ~430-450 lbs; later weaning 600-700 lbs
-Stocker cattle: weaning weight controls range 400-700 lbs
-Finished weight: 1000-1300 lbs
-Dressing (Hot carcass weight divided by the live weight) percentage 59-64% average 63%
Production Goals
-Calving interval every 365 days
-Percentage cows in heat by 60 days post calving = 80%
-Calf weaning weight should be 45-50% of cow’s weight
-Length of breeding season (cows need to be pregnant within 80 days post calving to maintain a yearly calving interval) is about 65 days for cows, 42 for heifers. Three chances to become pregnant during those 65 days = 21 days estrus cycle
-Pregnancy rate 90-95% for cows, 90% for heifers
Average age at weaning = 180 days
Backgrounding and stocker calves at pasture
-Goal: 700-800 lbs
-Overcome weaning stress and grow
-Add frame/lean tissue not fat. Support skeletal growth
**Most buyers purchase weaned calves in uniform groups of 40 or more*
-Uniformity allows to feed at same rate and treat with vaccines/feeding
-Grain to supplement may be needed or even forage during drought
Nutrient requirement for beef cattle
-NEg: net energy for weight gain = net energy for maintenance + and net energy for production (growth)
-CP (crude protein) coming in from feed. Two types, degradable intake protein and degradable protein protein. UIP goes to small intestine (small portion that scapes digestion by microbes and digested in small intestine as is). DIP is available to microbes and converted into ammonia. Ammonia that is produce need to be utilized quickly within the rumen, microbes use nitrogen, but if it builds up we risk ammonia toxicity, liver can’t detoxify so much and urea builds up. Microbes need energy for them to utilize the ammonia.
-Energy + DIP = MCP (microbial crude protein) you make more microbes and the protein becomes available to the animal
-UIP + MCP = MP (metabolizable protein) will be digested in the small intestine.
-Metabolizable protein requirement = UIP + MCP
Mineral Requirements
-Calcium (grains are low in calcium, forages are high in calcium)
-Phosphorous
-Ca:P can be important in steer bc of development of urinary calculi. Typically on a higher grain diet (>phosphorous)
-Magnesium (low in spring grass, concern for grass tetany)
-Salt
-Potassium
-Sulfur particularly needed when urea is added - toxicity is concern
Trace minerals
-Should always be supplemented
-May need to add VitB for stressed calves, can help
Environmental adjustment
-Thermoneutral zone: area where the animal doesn’t need to spend much energy in maintaining normal body temperature 32-77F
-BCS, coat (dry or wet, muddy) factors that affect thermoneutral zone
-Below LCT = cold stress
-Above UCT = heat stress
Lower Critical Temperature and Upper Critical Temperature
Effective temperature
-Important consideration when determining energy needs
-Needs to be adjusted when a lot of moisture, wind
LCT
-Cold stress increases energy requirements
-Increase about 1% per degree F below LCT
-As always do not want to make quick and drastic diet changes, slow and carefully increase feed and grain together.
BCS
-Affects reproductive performance and particularly the interval between calving to first heat. Shorter intervals to first heat cycle with higher BCS
-Cows with lower BCS = lower colostrum quality, calves will have lower IgG.
-Ruminant animals have huge GI tract, huge fluctuation in rumen or gut fill/gut fill. Can not depend on body weight to tell you much, could change 50lbs due to rumen fill
-Really high and really low BCS impede reproduction <5, >7.
-First time heifer should be at 6
-Cows that are above a BCS of 5 with reproductive issue things to consider are possible vitamin/mineral deficiency.
Heifer Development
-Target weight concept: 65% of mature weight at breeding and 85% of mature weight by the time they have their first calf.
-Feeding a heifer is probably the second most expensive aspect of cow-calf operations.
-Ex 1100 lb mature should weigh 715 lb at breeding
-Heifers should be fed separately from mature cows.
-11% CP and 36-42 Mcal NEg should be sufficient
Calves development
-Preconditioning: management method to prepare them for the auction
-Weaning very stressful, vaccination, transportation, change in diet. Don’t want to do at the same time.
-Castration of all males, vaccination. Feed bunk acclimated and weaned 30-45 days before sold.
Things to do before they are sold
-Preconditioned
-Quality assured (injection sites), all shots in front of shoulder to minimize muscle site blemishes
-Individual ID
-Source verified
-Age verified
Energy need for Stocker Cattle
-ADG (average daily gain) 0.5 lbs/day
-ADG 2-3lbs per day = grain mix at 1-2.5lbs/d (25-40% CP, ionophores, vitamins, minerals)
-Usually need to supplement protein for growing cattle (particularly UIP)
-12-16% CP (8% maintenance for microbes only)
-Supplement feed CP
-Urea does ok if feeding high energy diet but not high forage diets
Urea + high energy diet works well because plenty of energy for the microbes to utilize nitrogen.
-High forage (digested slowly) does not equal high energy. High forage + high energy would not be able to quickly utilize nitrogen in urea. Risking ammonia toxicity
Feedlot cattle
-Transition from pasture to high grain diet (acidosis and bloat risk, laminitis, liver abscesses)
-Slowly diet change weeks of transition, final ration 80%, so from 40 to 80
-CP 9-14% needs
-Need to supplement Ca, not phosphorous bc grain has it.
-Need forage in diet for proper rumen function
-Grain source depends on the location of the feedlot, corn (West), sorghum.
-Need to maintain DMI or sign that something is wrong during transition.
-Feedbunk and MONITOR FEED INTAKE: very important
-Fed ad libitum: little feed is left over, ensures that the cattle are eating all they can (minimize waste), don’t want too much left (indicates problems)
Nutritional Problems in Beef Cattle
Grass tetany
-Low magnesium in grass, spring grass, which are high in potassium = overall Mg deficiency in grass, C/S muscle twitching, incoordination, trashing, eventually death. Tx: IV magnesium
Nitrate poisoning
-Nitrates are reduced to ammonia in the rumen. As they are converted in the rumen get nitrates as intermediate, nitrite leads to methemoglobin (can’t carry oxygen) formation. High nitrates after pasture is fertilized or if you have water/weeds high in nitrates. C/S muscle tremors, tissue hypoxia and death.
Mycotoxins
-Corn feed or silage concern bc mold. Calves are more sensitive than adult cattle.
Urinary Calculi
-Grains bc they are high in phosphorus, steers sensitive
Sulfur toxicity
-Issue with distillers grains highly variable sulfur content. Sulfur is typically high when they come from ethanol plants. Risk factor for polioencephalomalacia. C/S milk fat depression, low rumen pH, sub-acute rumen acidosis (SARA).
-0.7% - 1.7% sulfur in distillers grains, requirement is only 0.18-0.24%
-Sulfur in rumen reduced to sulfide, and hydrogen gas accumulates, which starts to interfere with cellular metabolism, particularly the CNS is affected and blindness, recumbency, seizures, takes weeks to develop (polioencephalomalcia). Also develops when high intake of feed with thiaminases in plants or they can be produced by rumen microbes.
Grain overload/acidosis
Bloat (frothy and free grass)
Implant and additives
Growth Implants
-Hormonal: estrogenic group, androgenic group. They can be used at any stage of growth. They can increase the average ADG by 15-20% . Implanted into the ear.
-MGA (melengestrol acetate): progesterone analog given to heifers to suppress estrus, which increases stress and decreases DMI.
-Optaflexx (ractopamine) beta agonist. Repartitioning agent is something that will cause more nutrients to go towards muscle instead of fat. Only approved to be used in the last 28-42 days of finishing. Controversial agent, more death loss in cattle, most companies JBS, USA, Tyson, Smithville have banned its use, and other countries too.
Ionophores antibiotics
-Monensin (Rumensins), lasalocid
-Feed additives that selectively target some rumen bacteria, not used in human medicine so fine to use here.
-Goal is to modify rumen bacteria.
-Alter the profile of VFAs that are produced, decrease acetate and methane, increase propionate (and bacteria population that make it)
-Feed on high grain diets, improves feed efficiency and decreases incidence of acidosis
-Direct metabolism toward deposition of muscle
Lecture 14
Craig Datz (DVM)
caring.datz@royalcanin.com
Domestic Animal Nutrition
Overview
Pets (dogs, cats, birds, exotics)
Livestock: food and fiber producing. Nutrition is the key to get an animal to market weight. Marbling, quality of meat, etc.
Working, Sporting (farm animals, horses): racehorses need optimal nutrition key.
Zoos, aquariums, (exhibition, conservation)
Research (rodents, primates) lab animal nutrition is mostly done for you.
Other
Proper Nutrition
-Better health, longevity, of pets for example
-Fam animals
-Research nutrition needs to be standardized, protocols. Example, NSAIDs and arthritis, diet may have contributed to results.
“Five freedoms”
-From thirst and hunger
-From discomfort
-From pain, injury, and disease
-From fear and distress
Veterinary practice considerations
-Similar than pediatrician treating a child with parent in the room
-VCPR
-80-90% people say they leave office without hearing about nutrition
-Nutrition is important
Feeding Methods
Meals
-Once or twice per day, measured a fixed amount. Maybe 3-4 times for kittens
-Remove food that is not eaten or save
-Advantages: portion control, observed palatability, acceptance, appetite, intake, physiologic for dogs.
-Disadvantages: people may not know how much to put in the bowl or believe recommendations are too much/little. Requires time and effort. Not physiological for cats (eat often during the day)
Free-choice
-Food is always available
-Advantages: convenient, no special measurements, animal regulates its own intake. Eliminates begging behavior
-Disadvantages: limited portion control, risk of overweight/obesity, difficult to monitor appetite.
Time-feeding
-Food offered for a fixed period of time and then removed.
-Some times done during research studies
-May encourage engorging
Hand-feeding
-Coaxes animal to eat
-Reduces stress
-Requires the most time and effort, may lead to over or under feeding
Combination feeding
-For example wet food offered as a meal once a day, dry food fed free-choice
Commercial pet food
Dry (kibble)
-The most common way to feed
-Produced by extrusion (same as chex cereal), baking, meals, pelleting
-Needs preservatives
-Most economical, convenient, long-term storage, most sustainable. Most sustainable.
-May have lower salability, lack of variety of flavors, textures.
-Once opened within two months should be consumed. Loss quality, taste, fatty acids oxidized rancid.
Wet (can, trays, pouches)
-Produced by mixing and sterilization (heat, pressure)
-Long shelf life (5-10 years), convenient, palatable, variety of flavors, textures.
-Can be expensive, high water content (70-85%), high environmental impact. Bigger carbon foot print.
Frozen or Refrigerated
-Similar to above
-High environmental impact
-Freshpet provides the refrigerator
-Raw, cooked, partially cooked.
Freeze-dried
Commercial pet food diets
-Retail (over the counter)
-Veterinary diets
Retail diets
-Widely available, mostly intended for healthy pets
-Grocery stores
-Now online orders, no limits
Veterinary exclusive diets
-Prescription diet (trademark of Hills)
-Veterinary therapeutic or exclusive diet
-Prescription only means: FDA Rx product, it does not applied to pet diets because they are not regulated by FDA. It is not writing a prescription it is an order. Veterinarian has to authorize the order
What are the general categories of veterinary diets?
Home cooked diets
-Some owners prefer to avoid commercial pet food
-Some people do it right, but most do it wrong
-Food allergies are a good reason to make
Do not use recipes form internet
Balance.it.com trusted place
Lecture 15
Nutrient Categories
Protein
Fat
Vitamins
Minerals
Water
Macronutrients: protein, fat, carbohydrate
-Provide energy calories. Profile refers to the % of metabolizable energy (ME) proportions diet
Micronutrients: vitamins, minerals,
Macronutrient profile: always fills the 100%, there is no such a thing as a single high protein diet, low fat, etc., they all change to get the 100% Find it in the Guide
Nutrients
Try to get 100% of their requirements every day unlike humans
-Too much or too little not good
-Optimal range between reduced and high intake (target)
Protein
-Contain oxygen, nitrogen, carbon, hydrogen (some phosphorous or sulfur)
-Primary
-Alpha-helix
-Tertiary structure
Essential AAs bc you can’t make them
Dogs required 10 amino acids
Cats require 11 (taurine+)
Humans require 9
Animals and humans need AAs not Proteins
Functions of proteins and AAs
-Enzyme, hormones, neurotransmitters, antibodies, structural, mechanical, transport (Hb)
Deficiencies
-Decreased growth rate, weight loss, anemia, poor hair coat, decreased color (Tyrosine or Alenine deficiency = red coat)
Fat ans Oils
-Cholesterol and phospholipids are also examples of lipids
Fatty Acid
-FAs building blocks of of triglycerides
-Linear structures with a methyl end and a carboxyl
-Single bonds: saturated
-Double bonds: monounsaturated
-Two or more double bonds: polyunsaturated
-Short-chain FA: < 6 carbons
-Medium: 6-12
-Long: >6
Important ones (memorize)
Omega 3
-Alpha-linolenic acid
-Eicosapentaenoic Acid
-Decosahaenoic Acid
Omega 6
-Linoiec Acid
-Gamma-Linoienoic
-Arachidonic
Lecture 16 Macronutrients
Fat soluble vitamins
ADEK
Water Soluble vitamins
BC
Vitamin D function as what in the body?
Functions as a hormone in the body
Vitamin A
-Growth
-Deficiency: decreased vision or blindness, decrease immune function
Toxicity
-Born abnormalities: cervical spondylitis
-Feeding liver to animals, cod liver oil which contains too much (fish oil confusion), or excessive supplementation
-Dogs can take carotenoids (B-carotine) from plants and active vitamin A, CAT CAN’T.
Vitamin D
-Humans get is from sunlight
-Dogs and cats don’t, they have to have it in their diet
-Dogs narrowest therapeutic range 500 IU/kg to 3000 IU/kg. Cats more tolerant of excess
Toxicity
-Increased body calcium (higher Ca levels in blood)
-Production of Ca oxalate urinary stones
-Developmental musculoskeletal disorders
Vitamin E
Steatitis in cats: eating fatty fish without adequate E to prevent oxidation
Toxicity
-Not seen
Vitamin K
Chemical names
Important for blood clotting: factors II, VII, IX, X
-Essential but don’t know exactly the amount
-Cats have a minimum has been seen if excess consumption of fish
-Rodenticide toxicity: injectable available K1
-Chronic diarrhea: may need supplementation (shot if in hospital)
Thiamin (vitamin B-1)
-Coenzyme for metabolic processes
-deficiency not very common but happens
-Neurologic signs, lack of appetite, weight loss. CATS ventroflexion (also potassium deficiency)
-Lost 99% during heating process of food, they need to put a lot more of it in the food. Small pet food company may not analyze Thiamine content, poor quality.
Niacin (B3)
-Can be used as a drug to treat some autoimmune conditions dermatology issues NIACINAMIDE form
-Deficiencies: oral ulcers, tongue necrosis.
-Functions as a coenzyme
-Humans cholesterol Niacin
Cobalamin (B12)
-Necessary for RBC synthesis
-Deficiency in animals = anemia
-Ileum is the only part where it gets absorbed
Minerals
-Non organic
-Ash percentage in levels (what is left over after everything else has been burnt)
Lecture 17 Nutritional assessment and energy calculations
