Animal Nutrition Test 5 Flashcards
How many interactions are known to occur between pairs of minerals (if level of one is increased then digestibility, absorbability, or metabolizability of the other mineral is reduced)?
Over 45
How many mineral elements are required in the diet?
Good evidence for 20, many nutritionist think there’s more. The text says 22, but the specific 22 minerals can’t be nailed down from the reading)
When a mineral in the body has no function it’s called
An innocuous contaminant
Name the macrominerals
Mg2+ Na+ P (PO4) S Cl- Ca2+ K+
Name the microminerals
Si Mo Co Mn Zn Cu Se Cr I F Fe B
Example of mineral involved with hormones
Iodine is a part of the thyroxine hormone, which speeds up the body’s metabolism
Calcium constitutes what percent of bone wet weight?
9%
What percent of all body calcium is found in the bones and teeth? Soft tissues and blood?
99%, 1%
Minerals required for bone lengthening
Ca, P, Mg, F
Which vitamin is necessary for calcium transport across biological membranes?
D
Optimal dietary Ca:P ratios for nonruminants
1:1-2:1
How are fatty acids involved with Ca digestibility?
Fatty acids freed from fat digestion bind Ca, forming an indigestible fatty acid-Ca complex (similar to soap). This reduces Ca digestibility
Ca inhibits absorption of what mineral (besides P)?
Zn
Chronic Ca deficiency symptoms:
Rickets plus acute symptoms. Rickets is a disease of young growing animals which can also be caused by vit D deficiency or P imbalance
Acute Ca deficiency symptoms:
Muscle incoordination (wobbly walks), paralysis, even death. “Big head” disease in horses, various bone disorders
2 other names for calcium tetany
Milk fever
Parturient paresis
What species is milk tetany common in?
Dairy cattle, dogs, sows, and other species
When does milk fever usually occur?
Within the first 5 days after parturition (basically bc milk synthesis depletes the blood of calcium)
Problem with calcitonin and milk tetany
Female absorbs extra Ca during pregnancy and calcitonin helps deposit it in bones. But when lactation starts after giving birth, BLOOD calcium levels drop bc milk needs the calcium. The resulting low blood calcium stimulates parathyroid hormone production, but this is overridden by the calcitonin that is still present so blood can’t be released from bones, until several hours after the calcitonin was produced when it starts being destroyed. Then when the calcitonin is gone the danger of milk fever is gone, is the female lives that long
Modern and old-days treatment of milk fever
Modern: inject Ca, glucose, and Mg. The female will usually recover in less than 30 mins, but another injection may be needed to cure her
Old: reverse milk synthesis mechanism so the milk can be reabsorbed into body. This is done by inflating a cows udder with an air pump and a teat cannula and then sealing the teats with tape
Prevention of milk fever
- feed low calcium diet for 2 weeks before birth to stimulate parathyroid hormone, which will destroy calcitonin
- inject a big dose of vit D within 7 days prior to birth to stimulate extra ca absorption and therefore increase blood calcium levels (caution: if vit D is injected too soon then vit D toxicity, characterized by soft tissue and joint calcification, and milk fever may result)
What is the most versatile element found in livestock? Why?
P, it’s involved in almost every aspect of metabolism
What percent of all body P is found in the bones and teeth? Soft tissues and blood?
80%, 20%
Nearly all cells have P in them
Metabolic functions of P
- P combines with Ca to form crystals that resemble hydroxyapatite crystals, and these are components of hard tissues (therefore it’s indirectly controlled by same hormones as Ca bc it “follows” Ca)
- component of many enzymes (phosphoproteins)
- energy utilization (ATP for example)
- buffer in blood
- protein synthesis (P in RNA and DNA)
- lipid transport and metabolism and cell membrane structure (phospholipids)
Ca:P ratio in:
Monogastrics
Pigs
Laying hens
Growing chickens
Monogastrics: 1:1-1.5:1
Pigs: 1:1-1.2:1
Laying hens: much higher Ca bc egg shell is mostly Ca
Growing chickens: 2:1
Always check the current NRC or Extension Service recommendations
How much plant P is unavailable? Why?
1/2-2/3
Phytic acid in plants binds P and the complex (phytate P) is indigestible to monogastrics, which don’t have phytase to free the P from phytic acid
The phytate P in animal manure is an environmental problem
P deficiency symptoms:
- Rickets in growing animals
- decreased appetite and anorexia
- reduced productivity
- abnormal eating or chewing called pica (chewing on wood and bones, eating soil, and a depraved appetite)
- long term effects in adults result in lameness and reduced bone strength
Percent of Mg bound in bones?
70%
Remember: in terms of largest mineral presence, it goes Ca>P>Mg>others
:)
Functions of Mg
- bone development and maintenance
- needed by enzymes for optimal activity (all enzymes that hydrolyze ATP need it)
- carb, fat, and protein metabolism (bc of bullet above)
Deficiency symptoms of Mg
- neuromuscular hyperirritability (muscle spasms)
- skin lesions
- calcium deposits in arteries, kidneys, and soft tissue (arteriosclerosis?)
- reduced microbial fermentation in rumen and cecum
- retracted head in calves
- anorexia and reduced productivity
- grass tetany
- bone abnormalities
4 other names for grass tetany
Wheat poisoning
Grass staggers
Lactation tetany
Winter tetany
Low blood Mg levels
Grass tetany typically occurs in:
Beef cattle that are grazing lush green pastures, especially when they’re lactating (losing Mg in milk) or those grazing heavily fertilized pastures and those is colder temperatures (shivering depletes Mg)
(The grass is typically adequate in Mg but due to poor Mg absorption, blood, bone, and muscle Mg levels are reduced. The poor absorption can be caused by too much P and protein in the grass, so analyzing the grass for Mg alone won’t give you any advanced warning of grass tetany)
Symptoms of grass tetany
Standing alone Loss of appetite Easy excitability Viscousness Grinding of teeth Salivation Incoordination Collapse Convulsions Coma Death (usually the first indication that you have grass tetany unless you check your heard 3 or more times a day)
How long after first grass tetany symptoms are observed does death usually occur?
6-20 hours
Grass tetany treatment
Injection of calculi-Mg solution under the supervision of a vet, only if the animal hasn’t gone into a coma yet
If the animal has been unable to walk for a few hours before the treatment, results aren’t usually favorable. Also relapses after treatment are usually fatal.
Grass tetany prevention
Really difficult to prevent in grazing livestock bc of all the variables
1) fertilized supplemented with Mg, works best with sandy soils. Expensive solution
2) give each cow 2 oz/day of MgO mixed into a range cube or with grain. Tastes super bad so it’s hard to get them to eat it
3) limit grazing time or feed hay at night
4) feed lots of grain but it’s expensive and defeats the purpose of grazing
5) can also feed Mg carbonate, MgCl, or MgP. The poorest source of Mg is MgO but it’s cheapest
Mg deficiency may play a role in ______ in humans and animals
Osteoporosis
Which 3 minerals work together to maintain the osmotic balance in intracellular and extracellular fluids?
Na, Cl, and K
Which 2 minerals cause an animal to exhibit deficiency symptoms the fastest if deficient from the diet? Why is this bad?
Na and Cl. This is bad bc very few feeds contain enough salt (except seaweed, fish meal, and whey that hasn’t been desalted)
Is K usually deficient in a normal diet?
No, both plant and animal product are usually very high in K. However, supplementation of ruminant animals has been beneficial in recent years (especially after shipping stress)
Where are Na, Cl, and K found in vivo?
Na: extracellular fluid (90%)
K: intracellular fluid (90%)
Cl: both inside and outside of cells
The Na:K makes an electrochemical gradient surrounding the cell, which regulates nerve impulses and muscle contractions, so these two things are impaired during deficiency of Na and K
(remember the sodium potassium pump)
GENERAL deficiency symptoms for Na, Cl, and K
Anorexia, reduced growth, unthrifty appearance, reduced productivity; and death
3 functions of Na
1) acid base regulation (93% of bases in the blood have sodium. Think of bicarbonate!)
2) reduced reproduction
3) osmotic balance (water follows Na into the sweat gland)
Only direct water pumps in vivo are in the:
Heart
Intestines (peristaltic motion)
Lymph system
Na deficiency symptoms
Reduced growth rate Reduced feed efficiency Reduced milk production Weight loss Drinking urine and licking the ground in salty areas
3 Cl functions
1) acid base regulation (associated with 66% of blood acids)
2) component of gastric juice (HCl and salts)
3) osmotic balance, especially of extracellular fluid
Cl deficiency symptoms
Depressed growth rate
Other symptoms are probably masked by Na deficiency symptoms which are very fast and overwhelming
5 K functions
1) muscle and nerve functions (heart lesions and irregular heartbeat can happen when deficient in K)
2) osmotic balance
3) acid base maintenance
4) enzyme reactions
5) helps cells absorb AAs and glucose
K deficiency symptoms
Abnormal EKGs Growth depression Unsteady gait Muscle weakness Depraved appetite (pica) and wool biting in sheep Emaciation and death
Why is S the odd man out in mineral nutrition?
It has unique ties to AAs
It’s not required in inorganic form by the body
S functions through its presence in organic metabolites. What is it used to make?
The chondroitin matrix of cartilage Taurine Heparin Cysteine Other organic constituents of the body Feathers, gizzard lining, and muscles of birds
How does S deficiency affect sheep?
Reduced wool growth
Reduced weight gain of sheep and cattle
This can occur when you feed NPN instead of protein without supplementing S! However, these effects are the effect of inadequate microbial nutrition on which the host depends for synthesis of organic metabolites, so they can’t be considered as direct effects of S deficiency
Is S toxicity a major problem? Why or why not?
No, the intestinal absorption of inorganic S compounds is low
Fe is needed for proper ____ to occur in cells
Metabolism
What percent of body Fe is found in hemoglobin? In myoglobin in muscles and hemoglobin in RBCs combined?
Over 50%; 60-80%
What 3 molecules can the iron in hemoglobin bind to?
Oxygen, CO, and water
CO2 is carried back from the tissues to the lungs but it’s not attached to the iron directly
Is there enough Fe to meet requirements in most feeds? In milk?
Yes, no (especially in sows milk so baby pigs are susceptible to Fe deficiency)
How much hemoglobin can blood alone carry vs blood with hemoglobin?
1/2 (causes death by suffocation)
What plays the determining role for the homeostasis of iron metabolism?
Absorption (no excretion method!)
The intestinal mucosal cells control the amount of iron entering the animals body
Fe deficiency symptoms
Anemia (microcytic, hypochromic)
Diarrhea
Oral and skin lesions (due to tissue anoxia)
Decreased cytochrome activity (only in sever deficiency)
The thumps in baby pigs
Describe the thumps
Baby pig has a marginal iron supply when it’s born that lasts for 5-6 days. Sows milk has low iron content (lowest of all livestock species) and rapidly growing piglets are using all of their body iron
The thumps symptoms
Pallor of the skin Labored breathing Rough hair coat Poor and reduced growth Respiratory infections
Treatment of the thumps
1) inject soluble Fe solution into piglet before 6 days of age and then 1-2 weeks later depending on the product being raised. This method guarantees the pig will get enough Fe
2) oral dose of Fe with a stomach tube at about 4-6 days
3) Fe supplement coated with something sweet or iron water in pig pen
4) give piglets a chunk of dirt
5) feeding iron chelated to AAs to sow may help, but just feeding Fe won’t
Copper functions
Required for:
Fe absorption synthesis of hemoglobin bone collagen formation elastin formation (blood vessels) nerve transmission
Copper deficiency symptoms
Hypochronic anemia Deformed bones Ruptured aorta Incoordination Paralysis and infertility in cows
Copper (toxicity) imbalance effects
Tissue necrosis
Jaundice
Brown liver (due to Cu accumulation)
Cobalt function
Contained in vitamin B12, similar to sulfur in Met and Cys, so functions are those listed in B12
Cobalt deficiency symptoms
Called “wasting disease”
Listless Anorexia Weight loss Normochromic anemia Death
Cobalt (toxicity) imbalance effects
Thyroid hyperplasia (like goiter but goiter is tied to iodine)
Anorexia
Nausea
Diarrhea
Iodine function
Contained in thyroxin hormone
Iodine deficiency symptoms
Goiter (enlarged thyroid gland)
Hairless piglets
Premature aging
Lowered basal metabolic rate
Iodine (toxicity) imbalance effects
Vasodilation
Skin lesions
Nausea
Hyperthyroidism
2-3 g per 70 Kg of body weight is fatal in humans
Zinc functions
Required by several enzymes such as:
Carbonic anhydrase
Phosphatase
Other enzymes
Important in carb and amino acid metabolism
Zinc deficiency symptoms
Skin lesions Anorexia Slow growth Stiff joints Reduced serum zinc Impaired taste and dwarfism in humans Parakeratosis in pigs
Zinc (toxicity) imbalance effects
Reduces copper absorption Dermatitis Corrosion of the GI tract Diarrhea Possibly death
Selenium function
Component of gluthathione peroxidase (removes toxic peroxides, interacts with vit E which is an antioxidant so it prevents peroxide formation)
Se deficiency symptoms
“White muscle disease”:
Liver necrosis
Atrophy of the pancreas
When deficient simultaneously with vit E, results in muscular dystrophy in calves and lambs
Se toxicity (imbalance) effects
Blind staggers and alkali disease in western states Hair loss from tail in cattle and horses Hooves slough off Reproduction failure Anorexia Death
Toxicity symptoms are noted with as little as 9 ppm se in diet
Molybedenum function
Component of enzymes like xanthine oxide
Mo deficiency symptoms
Anorexia
Poor growth
Mo (toxicity) imbalance effects
Diarrhea
Anemia
Stiffness
Treatment: feed Cu above the requirement as Cu reduced Mo toxicity and vice versa
F function
Strengthens bone and teeth
Helps prevent dental carries (1 ppm in water)
F deficiency symptoms
Weak bone and teeth structure
F (toxicity) imbalance effects
Bones and teeth lose normal color and become thickened and soft
Mottled enamel in children
2-5 ppm in water produce toxic results in children
Fluorine is a cumulative process
Chromium function
??
Required for body cells to be sensitive to insulin
Chromium deficiency symptoms
Impaired glucose tolerance (decreased insulin sensitivity, glucose not absorbed)
Cornea (eye) lesions
Anorexia
Poor growth
Chromium (toxicity) imbalance effects
Unknown
Silicon function
Calcification of chick bone and connective tissue
Silicon deficiency symptoms
Small joints
Growth depression
