Flashcards in Repro Exam 3 Deck (275):
How much body water (in %) can an animal lose before it dies?
What are the 3 sources for total body water?
Drinking water, water in food, metabolic water
What are the functions of water in the body?
Solvent, transport medium, temperature regulation, participates in digestive processes, elimination of waste products
How is water lost from the body? Which method causes the most loss?
Urinary excretion = greatest loss; fecal excretion, evaporation
What is obligatory water loss?
Minimum amount of water required for the body to excrete waste products
What is facultative water loss?
Additional water excreted to maintain proper water balance
What factors affect voluntary water consumption – aka drinking?
Ambient temperature, type of diet, physiological status (health, level of exercise), water quality (taste), water temperature
What or how can we impact water consumption? (Increase it?)
Diet: abundant in water, increasing NaCl content; Increased: environmental temperatures, exercise, energy intake; tepid water preferred to cold water
For what reason(s) would we want to increase water consumption?
Diarrhea, increased: environmental temperatures, exercise and energy intake
How much of the body’s dry weight is protein?
50% or more
Large organic compounds containing carbon, hydrogen, oxygen & nitrogen; building blocks of proteins
What is the amine group?
What is the carboxyl group?
What is the “R” group?
Why are proteins considered acids?
made of amino acids ??
How many amino acids are there?
What is the difference between a simple and a complex protein?
Simple: contain only amino acids
Complex: simple protein combined with a non-protein molecule (ex: glycoproteins, lipoproteins)
Estimation of protein content based on nitrogen content
Protein that can be converted to a form that can be absorbed by the animal
What are the functions of protein in the body?
Structural components, muscle contraction, enzymes, hormones, blood clotting, antibodies, carrier substances
Of the functions in the body, which proteins do you think are the least digestible?
Keratin, Collagen, Actin & Myosin ????????
Amino acids that must be provided in the diet
essential amino acid
What are the essential amino acids? (Memorize them)
Arginine Histidine Isoleucine Leucine Lysine Methoinine
Phyenylalanine Taurine (cats only) Tryptophan Threonine Valine
PVT. MAT(T) HILL (Matt has 2 T’s if he is a cat)
Why must proteins be part of the diet?
Provide essential amino acids for protein synthesis
Provide nitrogen for synthesis of AA & other nitrogen-containing compounds
Can protein be used as an energy source?
Yes, if energy needs are not being met w/carbohydrates and fats
What does “positive nitrogen balance” mean in regards to diet?
Intake exceeds excretion; occurs when new tissue is being synthesized
What does “negative nitrogen balance” mean?
Excretion exceeds intake
What ways can the body lose protein?
Body tissues are being catabolized to provide energy
Inadequate levels of proteins/AA are being fed
Renal or gastrointestinal disease increases losses
What does the term “high quality protein” mean?
Contains all the essential AA’s
Essential AA present in the lowest quantity in a particular feedstuff; limits body’s ability to use that particular feedstuff to make body protein
limiting amino acid
What are the most common “limiting amino acids”?
Methionine, tryptophan, lysine
How does energy density of a diet affect protein requirements?
If the diet does not contain adequate levels of energy in the form of carbohydrates and fats, proteins will be used for energy. This type of diet must contain higher levels of proteins to meet AA and nitrogen requirements.
How does energy density of a diet affect the quality of protein required?
Diets that are very energy dense must contain higher % of protein when consumed or fed to just meet energy requirements. Because of the high energy density, the animal will stop eating before it has obtained all the necessary proteins.
How much of a plant is carbohydrates? (in percentage)
There are 2 major categories of carbohydrates, what are they?
Starches & sugars; Fiber
Which category is the most easily digested? Which is the most difficult?
Fiber most difficult; Starches & sugars most easily
In what form do animals store carbohydrates?
What is meant by the term monosaccharides?
Single unit sugars
Give some examples of monosaccharides and where they are found.
Glucose (prepared in corn syrup & sweet fruits)
Fructose (honey, ripe fruits, some veggies)
Galactose (not found in free form in foods)
What is meant by the term disaccharides?
Sugars made of 2 linked monosaccharide units
Give some examples and where they are found.
Lactose: milk; Sucrose: table sugar, sugar cane, beets, maple syrup
What is meant by the term polysaccharides?
Many linked monosaccharide units; starch, glycogen, fiber
Give some examples and where they are found.
Starch: commercial pet foods & cereal grains; Glycogen: liver & muscle; Fiber: plant material
Why can’t table sugar (sucrose) be used as an energy source in neonates?
They lack sucrase, the enzyme necessary to digest sucrose
Why are many adults (and most adult cats) unable to tolerate milk?
Lack lactase, enzyme necessary to digest lactose
Noncarbohydrate component of fiber, a polymer (made of long chain of linked units), non-digestible
Why is fiber hard to digest?
Contains lignan which is non-digestible; bonds between the monosaccharides in fiber are of chemical nature that resists breakdown by the enzymes of the GI tract
Why are ruminants (and other herbivores) able to “digest” fiber?
Certain microbes can break down fiber to varying degrees
The process of “digesting” fiber is called _________ and releases __________.
Fermentation; short-chain fatty acids (SCFAs)
Can monogastrics absorb SCFA’s?
Not to any significant degree
Why is fiber necessary in the diet?
Provide source of energy only to cells of colon
What effect does fiber have on energy density of a diet?
Decreases energy density of diet; useful for weight control diets
The feeling or state of being sated
What would you expect to happen to the volume of stool in an animal fed a high fiber diet?
Do carbohydrates play a role in protein synthesis?
Yes, source of carbon for synthesis of nonessential AA’s
Synthesis of glucose by the liver
Compare the relative carbohydrate content in feeds manufactured for livestock, dry pet foods and canned pet foods.
Livestock: large proportions
Dry pet foods: moderate amounts
Canned pet foods: little to no carbohydrates
What are the differences between fats and oils?
Fats: lipids of animal origin, except marine mammals
Oils: liquid fats usually of plant or marine mammal origin
Carboxylic acid with long hydrocarbon tails; Basic building block of fat (along w/ triglycerides & glycerol); Found in animal & plant materials
What are lipoproteins?
Lipid + protein
What are phospholipids?
Lipid + phosphoric acid & nitrogen
What are glycolipids?
Lipid + carbohydrate
Another term for fats & oils, make of 3 fatty acids linked to a molecule of glycerol
A type of fat that contains no double bonds between carbon atoms; carbon atoms saturated w/hydrogen
a type of fat that contains 1 or more double bond between carbon atoms
In human nutrition, which is the “good fat” and which is the “bad fat”?
Unsaturated = good; Saturated = bad
What has more saturated fatty acids, oils or fats?
Conversion of unsaturated fatty acids to saturated fatty acids; hydrogen is added to the molecule
What is the process by which transfats are produced?
Why does ruminant body fat contain a high percentage of saturated body fat?
Because rumen bacteria cause hydrogenation
Fat has 4 major roles in the body, what are they?
Stored energy, insulation, structural (cell membranes), nutrient transport
Fat has 3 major roles in the diet, what are they?
Source of energy and essential fatty acids (EFAs) and improves palatability and texture
How does fat affect the energy density of a diet?
Substantially increases the energy density of the food
A fatty acid that cannot be produced by the body at a rate sufficient to prevent disease & must be supplied in the diet
essential fatty acid
Linolenic acid; an EFA in cats and other species if linoleic acid is not present in sufficient concentration
What is arachadonic acid a precursor molecule for?
Linoleic acid (?)
In what species is arachadonic acid an essential fatty acid?
an EFA in cats and other species if linoleic acid is not present in sufficient concentration
What are symptoms of essential fatty acid deficiencies? There are 4 major ones.
Poor coat: hair loss & skin lesions
Decreased reproductive efficiency & lactation
Liver & kidney abnormalities in kittens
What does the term “rancid” mean?
What makes a food become rancid?
Fats exposed to high temperatures for excessive periods undergo oxidation = rancid fat unavailable to animal
Why is vitamin E sometimes (usually) added to diets that have a high content of polyunsaturated fatty acids?
Excessive ingestion of polyunsaturated fatty acids (PUFAs) can result in an increase in the dietary vitamin E requirement
Besides being an important vitamin, why is vitamin E used in manufacturing animal feeds?
Vit E is preferentially oxidized before PUFAs, protects PUFAs from rancidity
What is one clinical syndrome that occurs when feeding diets low in vitamin E?
pansteatitis (yellow fat disease) can occur in cats
What are the clinical signs of pansteatitis?
Depression & anorexia, increased sensitivity to touch on chest and abdomen, reluctance to move
Diets made up largely of ______ can result in hypovitaminosis E.
PUFAs, primarily fish products
Why must a cat eat animal fat? (or, why can’t a cat utilize plant oils?)
The only source of arachidonic acid is animal fat
What are the criteria for being a vitamin?
Organic molecules, required in extremely small amounts, essential for normal metabolism, deficiency symptoms or illnesses result when there is not enough present in the body, cannot normally be synthesized by the body
What are the fat soluble vitamins?
A, D, E, K
What is a provitamin?
Provitamins are converted to active vitamins by animal cells
Do deficiencies of fat soluble vitamins happen rapidly or slowly?
Slowly because they can be stored in the liver and body fat
Is it possible to develop toxicities with fat soluble vitamins?
There is a potential for toxicity
What are the water soluble vitamins?
B-complex (Thiamin, riboflavin, pyridoxine, cyanocobalamin, pantothenic acid, nicotinic acid, folic acid, biotin, choline) and C (ascorbic acid)
Do deficiencies of water soluble vitamins happen rapidly or slowly?
Is it possible to develop toxicities with water soluble vitamins?
Toxicity unlikely since they are not stored in the body
How are water soluble vitamins eliminated from the body?
Excreted in urine
What is ascorbic acid?
What does vitamin A do in the body?
Maintenance of epithelial tissues, vision, bone growth, reproduction
What is/are the sources of vitamin A?
Carotenoids, a yellow/orange pigment synthesized by plants
Most plentiful Carotenoid (provitamin A) and has the highest biological activity
Is the concentration of vitamin A higher in fresh grasses or stored hay?
Higher in fresh grasses
Why iss the concentration of vitamin A higher in fresh grasses?
Vitamin A is destroyed by oxidation
Do animal products (meat) contain vitamin A?
No, fish liver oil, milk, liver, and egg yolk may contain vit A
How are precursor vitamins converted to Vitamin A?
Enzymes in intestinal mucosa convert carotenoids to active vit A
Why do felines require actual, active vitamin A?
Felines lack the intestinal enzyme that converts carotenoids to active vit A
What are symptoms of vitamin A deficiency?
Night blindness, impaired growth, reproductive failure, loss of epithelial integrity, dermatoses, abnormal bone & tooth development
In what species would you most likely see vitamin A deficiency?
Ruminants, esp thos maintained on range only over the winter
What are symptoms of vitamin A toxicosis?
Skeletal abnormalities, skin abnormalities, anorexia & weight loss, hyperesthesia
What is vitamin D?
A group of compounds that regulates Ca and P metabolism
What is the precursor to vitamin D?
Ergosterol ergocalciferol Vit D2
Where is vitamin D activated?
Liver and kidney
What is vitamin D3?
Inactive storage form of D3
What is another name for vitamin D3?
What is the active form of vitamin D?
What hormone controls conversion of the precursor to vitamin D to the active form of vitamin D?
Parathyroid hormone (PTH)
What is the function of vitamin D in the body?
Increases plasma Ca & P: increases efficiency of intestinal absorption of dietary Ca & P; mobilizes Ca from bone; increases P reabsorption in the kidneys
What are symptoms of deficiencies of vitamin D in growing animals?
Rikets: abnormal bone development results in bowing of legs & thickening of joints
What are symptoms of deficiencies of vitamin D in adult animals?
Osteomalacia: impaired bone mineralization
Which type of animal is most susceptible to vitamin D deficiencies?
Exotic pets: reptiles, especially iguanas
What are symptoms of vitamin D toxicosis? (hypervitaminosis D) (know these – they are important symptoms for a wide variety of pesticides.)
V/D, weakness, PU/PD, muscle tremors, seizures, anorexia, hematemesis, constipation, melena, & loss of body weight
What is the chemical name for vitamin E?
Tocopherol & tocotrienols
Where is vitamin E stored?
Fat and liver
What is the function of vitamin E in the body?
Potent antioxidant in body and diet, spares selenium
Are vitamin E deficiencies common?
Uncommon, seen in dogs & cats fed poorly prepared or poorly stored food
What are the symptoms of vitamin E deficiency?
Muscle degeneration, decrease reproduction performance, pansteatitis in cats
What are the 3 forms of vitamin K?
Vit K 1, 2, 3
Where are the 3 forms of vitamin K found or made?
K1: green plants; K2: synthesized by bacteria in the rumen and large intestine; K3: synthetic form
What foods provide vitamin K?
Green leafy plants, liver, fish, eggs
Vitamin K is important in blood clotting cascade. Which clotting factors are vitamin K dependent?
II, VII, IX, X
Dicumerol is an anticoagulant. What rodenticide agents are based on dicumerol?
What plant produces dicumerol when it spoils?
What are the functions of B vitamins in the body? (Broad statements)
Act as coenzymes in tissue synthesis & energy metabolism; involved in the use of food energy; involved in cell maintenance and growth &/or blood synthesis
List the B vitamins.
Thiamin, riboflavin, niacin, pyridoxine, pantothemic acid, biotin, folic acid, cobalamin, choline
Which B vitamins are involved in energy production?
Thiamin, riboflavin, niacin, pyridoxine, pantothemic acid, biotin
Which are involved in growth and cell maintenance?
Folic acid, cobalamin, choline
What is Vitamin B1? Alternate name?
Functions in carb metabolism, thiamin
In what feedstuffs is B1 found?
Meats, wheat germ, whole grains, many forages
What are symptoms of vitamin B1 deficiency?
CNS dysfunction, anorexia, weight loss, anemia
What is vitamin B2? Alternate name?
Riboflavin, functions in energy metabolism
What is the source of B2 in the diet?
Milk, organ, meats, plants
What is Vitamin B3? Other name?
Nicotinic acid, niacin; functions in several metabolic pathways involving use of energy-containing nutrients
What is the source of vitamin B3?
Leafy plants, meat
What are the symptoms of Vitamin B3 deficiency?
What is folic acid?
Functions in synthesis of DNA
In what feedstuffs is folic acid found?
Leafy green plants, organ meats, soybean meal
What are symptoms of folic acid deficiency?
Decreased cellular reproduction: reduced growth, anemia, leucopenia, birth defects
What type of birth defect(s) can be caused by folic acid deficiency?
What is Vitamin B12? What is its other name?
Cobalamin or cyanocobalamin
What does vitamin B12 do in the body?
Involved in biochemical reactions & metabolism of fats & carbs
Where is vitamin B12 found?
Only found in food of animal origin
What are symptoms of vitamin B12 deficiency?
Rare, anemia, impaired CNS function
What is the scientific name for vitamin C?
For which specie(s) would vitamin C be considered “essential”?
Humans and guinea pigs
What does vitamin C do in the body?
Formation & maintenance of collagen (important in bone, teeth, & connective tissue); antioxidant (immune system)
What are symptoms of vitamin C deficiency? (there are many!)
Unlikey but impaired wound healing, loosening of periodontal ligaments (tooth loss), capillary bleeding, anemia, poor bone formation, increased incidence of upper respiratory disease
What is the deficiency of vit C called?
What foods have increased levels of vitamin C?
Parsley, cabbage, green peppers, kale (lettuce poor in Vit C)
What makes something a “mineral”?
Inorganic elements “ash” necessary for maintenance and production. Cannot be synthesized by body or microorganisms
Must minerals be provided in the diet?
What is meant by the terms “Macroelement” and “Microelement”?
Macroelement: required by body in relatively large amounts
Microelement: required by body in very small amounts, trace minerals
What are the “Macroelements”? (Memorize)
Ca, P, Mg, Sulfur (S), Na Cl, K
What are the “Microelements”? (Memorize)
Fe, Copper, Cobalt, Zinc, Iodine, selenium, manganese, fluorine, molybdenum, vanadium, chromium, silicon, nickel, tin
What functions do minerals serve in the body? (there are 5)
Ossification (bones & teeth), enzyme cofactors, nerve transmission, muscle contraction, components of organic compounds
How much calcium is found in the serum?
Less than 1%
What hormone regulates calcium levels?
Parathyroid hormone (PTH)
What is calcitonin and what does it do?
Released from thyroid gland & in response to hypercalcemia; reduces plasma Ca levels
What are the sources of calcium in diets?
Dairy products, meat & bone meal, bone
What conditions occur as a result calcium deficiency? (there are 3)
Rickets in growing animals; osteomalacia in adults; parturient paresis: milk fever, result of hypocalcemia in early lactation
What is nutritional secondary hyperparathyroidism?
Deficiency of Ca in diet, results in chronic release of PTH & bone demineralization
How does nutritional secondary hyperparathyroidism occur?
Animals are fed diets deficient in Ca (table scraps) and increased in P
What are the symptoms of nutritional secondary hyperparathyroidism?
Periodontal disease, loss of teeth, rubber jaw, skulls enlarged by deposition of matrix in horses – matrix doesn’t ossify, skull feels soft, miller’s disease
Although phosphorus levels are high in grains (wheat, corn, oats, etc.) it is not usable by non-ruminants. Why?
Bound to phytate, poorly absorbed by non-ruminants
Why is it important for diets to be balanced with respect to calcium and phosphorus ratios?
Homeostatic mechanisms are closely interrelated. Feeding an excess of either will result in a decreased absorption of the other.
What are the major sources of magnesium in the diet?
Grains, legumes, dairy products
What condition occurs in animals fed a diet with excessive amount of magnesium?
What condition can occur in cattle fed a diet with a deficiency in magnesium?
What are the symptoms of grass tetany?
Neurologic signs including seizures, coma, death
Under what conditions is a dietary deficiency in magnesium most likely to occur?
Cattle grazing on lush green pastures
What 2 amino acids are responsible for containing most of the body’s sulfur?
Cystine & methionine
Charged particles or substances that separate into charged particles when in solution
What are the 3 most common mineral electrolytes?
Na, Cl, K
Where is the majority of sodium in the body found?
What is an “effective osmole”?
Chemically attracts water molecules and holds them
Theoretically, what problems could be caused by feeding a diet high in sodium ?
Increased H2O intake, hypertension, increased H2O retention (increased load on heart, exacerbate symptoms of congestive heart failure, increase work load on kidneys)
Where is the majority of chlorine in the body found?
Where is the majority of iron in the body found?
Is iron absorbed from the diet well?
No, only 5-10% is absorbed
Which is better absorbed, Ferrous iron or ferric iron?
In what ways would iron be lost from the body?
External hemorrhage is only significant Fe lost, ex: parasites, parturition, trauma, sx
Which specie(s) are prone to iron deficiencies?
What changes on the CBC might be expected in an iron deficient patient?
Fe deficiency is rarely a problem
What are the symptoms of copper deficiency?
Anemia, depigmentation of hair & skin, abnormal bone growth
What are the symptoms of zinc deficiency?
Skin lesions, depigmentation of skin & hair, growth retardation, reproduction failure, abnormal bone growth
What condition can occur in animals fed a diet deficient in iodine?
What conditions occur as a result of excessive selenium in the diet?
Hairloss, hough sloughing, repro failure
What conditions occur as a result of deficiency of selenium in the diet?
White muscle disease, liver necrosis, reproduction failure
In what species does “white muscle disease” occur?
What are the symptoms of “white muscle disease”?
Weakness, lameness, sudden death
Contains seed pigment, protein and fiber; sometimes includes the aleurone layer
What is the primary component of the endosperm of a seed?
What is the germ of a seed?
Which amino acids are usually the limiting amino acids in a cereal grain protein?
Lysine and/or methionine
Why is corn considered the “feed grain of choice”?
Produces more energy per acre than other crops; adapted to many climates
Why do animals fed diets high in corn or corn oil usually have relatively healthier hair coats?
High oil content
Which cereal grain contains vitamin A?
Does mold have to be present on corn for it to be contaminated with mycotoxins?
What are the effects of Zearaleone?
What pathologic condition results when corn contaminated with fumonsin is fed to horses?
Equine leukocencephalomalacia: causes degeneration of the cerebellum in horses
What pathologic condition(s) can be caused by aflatoxin?
Causes decreased feed intake, poor growth, & diarrhea; potent carcinogen: liver cancer
How can corn be checked for the presence of aflatoxin?
Will glow under black light
Oats are an important source of energy for which species?
Kernel without a hull
In what nutrient category are oats the most superior in? (they have the best____?)
Wheat is considered the world’s most important crop. So why isn’t it used extensively as feed for livestock?
Too expensive to feed livestock; unpalatable if finely ground
However, wheat is important in feeding cattle. How is it used?
Cattle allowed to graze on whole plant when it is young, then they are pulled off so the plant can mature
How is wheat bran used in animal feed?
Used in horse, cattle, and rabbit feed and farrowing sows
What is grain overload?
Problem that occurs most often in a feedlot setting
How does it happen (what causes it to happen)?
Animals pulled off pasture to be fed diets high in grain.
What pathologic condition results from grain overload in cattle?
If switch occurs too fast: increase in lactic acid producing bacteria
Lactic acid reduces pH of rumen: stops growth of bacteria & further reduces rumen pH
*Results in ulcers of ruminal wall
What pathologic condition results from grain overload in horses?
Can “grain overload” occur in other situations?
Horses eating lush green, fast growing pasture in spring & fall (clover pastures)
Product of the sugar cane-refining industry
Why is molasses used in diet formulations?
Energy source, increases palatability, mineral source, manufacturing of feed
Why is beet pulp sometimes used in horse feed?
High in digestible fiber
Liquid remains produced during cheese processing; contains lactose, minerals, & water-soluble proteins
Protein supplements must have at least ______% protein
What does the term “meal” mean?
Any ingredient that has been cooked, dried, & ground (reduced in particle size)
What are the common “oil seeds”?
Rapeseed, linseed (flax), canola, cotton seed, olive, palm, peanuts, safflower, soybean, sunflower
The most important protein supplement for non-ruminant live-stock feeding is ______.
Why must soybeans be “cooked” (exposed to heat) before use as a protein source in animal feed?
Raw soybeans are toxic to most animals, but toxins are destroyed by heat treatment
What part of the cotton plant is used as a protein supplement in ruminant diets?
Cotton seed meal
What is gossypol?
Toxic compound found in cotton plant
What animals are affected by gossypol?
Calves, lambs, monogastrics
What are the effects of gossypol on the animals eating it?
Affects heart & liver, causes anemia
Give examples of legumes.
Soybeans, field beans, peanuts, lentils, peas
Where does corn gluten come from?
Residue from production of: corn starch, fructose, corn syrup, corn oil
Why is protein from animal sources considered “high quality”?
Contain good balance of amino acids and vitamin B12 which is not found in plant protein
What vitamin is also referred to as “animal protein factor”?
What diseases can be transmitted by feeding protein obtained from animal sources?
Bovine spongiform encephalopathy (mad cow disease); scrapie; Creutzfeldt-Jakob disease; E. coli; salmonella
What is the difference between “meat meal” and “meat and bone meal”?
Products of rendering plant & slaughter house wastes
If bone is included, the resulting product is meat & bone meal
Why is ammonia sometimes fed to ruminants?
Rumen microbes synthesize AA’s using nitrogen in ammonia
Which amino acids can be “man-made”?
Lysine, methionine, taurine
What does the term “forage” mean?
Vegetable material in fresh (pasture and other grazed roughage), dried (hay), & ensiled (silage) states
List some characteristics of roughages.
Bulky – low weight per volume, high in fiber, low in energy, lower in digestibility than concentrates, tend to be high in minerals & vitamins, variable protein
Give some examples of “grasses”.
Bromegrass, fescue, bluegrass, barley, oats, timothy, wheat
Do humans eat “grass”?
Which is more nutritious, young grasses or mature grasses?
What is the major distinguishing characteristic of a legume?
Ability to utilize atmospheric nitrogen
Is a peanut a pea or a nut?
It’s a legume
What are some advantages of using land for pasture?
Lessen feed costs & capital expenditures; good source of vitamins & minerals; reasonable source of protein if well managed; reduced threat of communicable diseases; provides exercise; management skills not as critical; makes use of otherwise non-productive land
What are some disadvantages of using land for pasture?
Some pasture land could bring higher return from other uses; animals are harders to check and handle; potential for predation; natural weather changes; must maintain pasture land (toxic plants)
What does the term “ideal stocking rate” mean?
Perfect balance between rate of harvest by animals & rate of new growth of plant
Compare continuous grazing to rotational grazing. What do those terms mean? What are advantages and disadvantages to each technique?
Continuous grazing: animals on same pasture year round. Disadv: less efficient use of pasture – high stocking rates will leave plants denuded of foliage; low stocking rates – plants will mature & become less nutritious
Rotational grazing: most of foliage is harvested; pasture rests during regrowth; animals constantly provided w/young, nutritious plants; pastures are evenly fertilized w/manure; plants regrow vigorously
How is “winter wheat pasture” used in the livestock industry?
Cattle put into wheat fields to graze from fall until spring, cattle removed in spring, young wheat plants are high in soluble protein & carbs
Forage harvested during growing period & preserved by drying for later use
What are advantages of feeding “hay”?
Long term storage possible; good source of vitamins & minerals; facilitates digestion in herbivores being fed high energy diets; once harvested, easy to handle & feed
What are disadvantages of feeding “hay’?
Harvest requires considerable labor & expensive equipment; loss of leaf material occurs during harvest; some loss of nutrients during harvest & storage; spoilage & combustion can occur in improperly cured hay; presence of toxic material/pests; some hay fields could bring high return from other uses
Stems & leaves after removal of seeds; usually used for bedding; occasionally used for roughage
What is “prussic acid”?
What plant accumulates “prussic acid”?
When would you expect to see “prussic acid” toxicity most often?
In mature plants, drought, freezing
What are symptoms of “prussic acid” poisoning?
Animal often dead; Csx: excitement, rapid pulse, generalized muscle tremors, salivation, lacrimation, voiding of urine & feces, bright pink mucous membranes, blood bright cherry red
What would blood drawn from a patient with “prussic acid” poisoning look like?
bright cherry red
What “drugs” are used to treat “prussic acid” poisoning?
Tx w/sodium nitrate & sodium thiosulfate
Which plants are implicated in nitrate toxicity?
Sorghums, winter wheat, heavily fertilized grasses
How do nitrates cause toxicity?
Nitrates are reduced to nitrites in the rumen. Nitrites absorbed into the bloodstream. Nitrites oxidize the iron in Hb. Converts hemoglobin to methemoglobin which cannot carry O2.
What would blood drawn from a patient with nitrate toxicity look like?
Chocolate brown color
What is “grass tetany”?
Metabolic disorder caused by hypomagnesemia; associated w/consumption of young lush grasses
Loss of blood supply to feet & extremities caused by fescue toxicosis
What roughages are associated with bloat?
Winter wheat & alfalfa
What is cantaridin?
Comparable to cyanide & strychnine in toxicity, produced in blister beetles
What species is most susceptible to cantharidin toxicity?
What are the symptoms of “blister beetle” poisioning? (Cantharidin toxicity)
Severe skin inflammation & blisters; colic; elevated temps; depression; increase HR & RR; dehydration; sweating; diarrhea; frequent urination
From slide with pictures: depression, looking at flank, lying down more than usual, rolling, stretching, dog sitting
Which species of blister beetle has the highest content of cantharidin?
Striped blister beetle
Describe ways to manage pasture and hay to avoid cantharidin toxicity.
Use first cutting for horse feed since beetles not active then
Cut on schedule
Do not crimp or crush hay if beetles are present
Do not use hay conditioner when harvesting infected alfalfa
Check fields w/flowering plants before harvest