Bret McNabb, DVM MPVM DACT
www.bpc.edu
MACROMINERALS
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Calcium
Magnesium
Phosphorus
Potassium
Sodium
Chloride
Sulfur
MICROMINERALS
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Chromium
Cobalt
Copper
Iodine
Iron
Manganese
Molybdenum
Nickel
Selenium
Zinc
Olson et al, VCNA, 2007
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Necropsy
Liver biopsy
Blood
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Supplemental feeds
 Intended for limited intake
 Variable consumption
 Formulation – inorganic vs. organic or “chelated” form
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Individual supplementation
 Ensure administration
 More labor intensive
▪ Oral bolus
▪ Injectable formulations
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Absorbed in the small intestine
 Pre-ruminants – 70% absorbed
 Ruminants – 5% absorbed
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Liver is the primary storage organ
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Functions:
 Growth and development
 Immune system
 Metabolism
 Pigment deposition (melanin)
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Life Stages
Beef cattle – 10 mg Cu/kg diet
 Breed: Simmental, Charolais more sensitive to copper deficiency
than Angus
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Dairy Cattle – 13-16 mg/kg diet
 Breed: Jerseys tend to accumulate more copper than Holsteins
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Molybdenum (Mo) and sulfur (S)
bind copper in the rumen
 Can’t absorb copper
 Need the correct ratio
SO4
Sulfate
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Dietary copper:molybdenum ratio <2:1
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Primary vs. secondary
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Signs are often non-specific
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Weight loss, diarrhea
Infertility
Anemia
Decreased hair pigment
Spontaneous bone fractures
Weak immune system
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Rare in cattle, common in sheep
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Acute vs. chronic exposure
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Clinical Signs
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Plasma Cu levels increase 10-20 fold
Icterus, significant hemoglobin loss via kidneys
Lethargy, weakness, depression
Diarrhea
Excessive thirst
Death within 1-2 days
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Cu Status
Plasma Cu
(ug/ml)
Liver Cu (ug/g)
DM
Deficient
<0.5
<35
Marginal
0.5-0.7
35-100
Adequate
0.7-1.3
100-300
Toxic
>1.5
>500
Serum/Plasma levels
 Maintain near normal levels until liver Cu drops below 35ppm
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Liver Biopsy
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Salt Mix Supplementation
 Copper oxide (CuO) – 80% Cu
 Copper sulfate (CuSO4) – 40% Cu
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Rumen bolus
 Copper Oxide Needles
▪ 25g for cattle >500lbs.
▪ 12.5g for cattle 150-500 lbs.
 Last 6-8 months
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Injectable Products
 Copper carbonate (Multi-Min)
▪ 15mg Cu/ml
▪ Cow: 1cc/200lbs
 Copper glycinate (Cuprate, 30% Cu by weight)
▪ No longer available
 Toxicity potential
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Soil
 More available in acidic (low pH) soil
 Toxic conditions – can add lime or gypsum to alkalize soil and
reduce uptake
www.luresext.edu
Glutathione Peroxidase (GSH-Px)
Iodothyronine 5’-deiodinase
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Absorbed primarily in the small intestine (duodenum)
Lower absorption in ruminants than monogastrics
REQUIREMENTS
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Cattle
0.1 – 2 mg/kg Se in diet
SOURCES
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Sodium selenite
Sodium selenate
Selenomethionine
 Bioavailability is 2x greater
Sub-clinical Se deficiency &
Se-responsive syndromes
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Sulfur Interactions
 Interferes with Se uptake by plants
 Se metabolism in ruminants
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Musculoskeletal
Reproductive
Gastrointestinal
Immunologic
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White Muscle Disease (Nutritional Myodegeneration)
 Cardiac (heart) form – Can occur within 2-3 days after birth
▪ Necrosis/calcification of myocardium and intercostal muscles
 General disease is generally 1-4 weeks of age
▪ Lame, stiff, reluctant to move
▪ Pale muscles
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General Weakness
 Less severe form
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Adult myodegeneration
 May be caused by exercise or stress
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Reproductive Loss
 Late-term abortion
 Early embryonic loss
 Prolonged pregnancy
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Infertility
 Lowered sperm motility in bulls
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Retained Placenta
 Altered white blood cell function
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Gastrointestinal System
 Diarrhea
 Generalized ill-thrift
 Decreased feed efficiency
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Immune System
 Lowered white blood cell function
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Acute – respiratory distress, uncoordination, abnormal posture,
death
Chronic – Anorexia, emaciation, lameness, cracked/deformed
hooves, hair loss
Reproductive problems
 Abortion
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Mechanism – interferes with/replaces sulfur in amino acid
structure (cysteine and methionine)
 Over-supplementation
 Se-accumulating plants (Astragalus spp, Vetch)
▪ Forages >5mg/kg Se can lead to chronic toxicosis
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Whole blood
Liver sample
Feed or soil samples?
Se Status
Whole Blood Se
(ppb or ng/ml)
Liver Se
(ppm or ug/g) DM
Deficient
<50
0.1-0.4
Marginal
50-80
0.5-0.8
Adequate
100-350
0.9-1.75
Toxic
5,000
20-150
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Injectable formulations (sodium selenite, 2.19mg = 1mg Se)
 Therapeutic and short-term supplement
 Provides partial Se supplementation for 30-45 days
1mg Se/ml
2.5-3.75cc/100lbs
(0.055 mg/kg BW)
5mg Se/ml
1cc/200lbs
(0.055 mg/kg BW)
2.5mg Se/ml
1cc/100lbs
(0.055 mg/kg BW)
5mg Se/ml
1cc/100-200lbs
(0.055-0.11 mg/kg BW)
Maas, et al, 1993
Maas, et al, 1993
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Rumen bolus (Pacific Trace Minerals Inc., Se 365 Bolus)
 8-10% elemental Se
 Beef cattle only, over 3 months old
 Slow release (3mg/day) over a 1-year period
Renquist, et al, 2007
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Salt Mix
 Assume 1oz/day consumption
 Cattle maximum: 120ppm sodium selenite
 Sheep maximum: 90ppm sodium selenite
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Essential component of metalloenzymes
Thousands of metabolic pathways with zinc-requiring
proteins
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Absorbed in duodenum
 70% dietary Zn absorbed
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Excreted via pancreatic secretions
and feces
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Gene expression
 Most apparent in rapidly-dividing cells
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Appetite control
 Zn decreases cholecystokinin and leptin
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Fat absorption
 Pancreas secretes phospholipase A2
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Antioxidants
 Superoxide dismutase
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Beef Cattle: 20-30mg/kg diet
Actual requirements
 Maintenance 0.1mg/kg BW
 Growth: 24mg/kg weight gain
 Pregnancy: 1.1-6.3 mg Zn/day
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Sheep: 20mg/kg diet
Actual Requirements
 Maintenance: 0.1mg/kg BW
 Growth: 24mg/kg weight gain
 Pregnancy: 0.28-1.5mg Zn/day
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Anorexia, reduced growth rates…pregnancy toxemia
Thickened skin and alopecia
Skeletal abnormalities, conformational issues
Compromised immune function
Reproductive disorders
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Reduced testicular size in Zn-deprived calves
Reduced spermatogenesis
Loss of libido
Reduced fecundity and birth weight
Redistribution during stress
Facial eczema?
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Fairly tolerant to high [Zn]
Effects when Zn > 500mg/kg diet
 Reduced volatile fatty acid production (vulnerable microbes)
 Decreased appetite and pica
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Plasma Zn – 60% is albumin-bound
 Reduced during microbial infection, parturition, hyperthermia
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Glass blood tubes with rubber stoppers contain Zn
Zn Status
Plasma Zn
(ppm or ug/ml)
Liver Zn
(ppm or ug/g)
Deficient
<0.4
<30
Marginal
0.5-0.8
30-40
Adequate*
0.8-1.4
50-100
Toxic
>5.0
>300
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Organic vs. Inorganic Sources
Zinc Oxide
Inorganic
Zinc Sulfate
Zinc Methionine
Organic
Zinc Proteinate
 Multi-Min
▪ 60mg Zn/ml
▪ Cattle: 1cc/200lbs = 0.14 mg/kg
 Inject-A-Min
 Mineral Max
Richeson et al
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Required for the synthesis of vitamin B12
 Propionate metabolism
 Gluconeogenesis (Malonyl CoA → Succinyl CoA)
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Diet requirement (cattle): 0.1mg/kg diet
Deficiency – relatively rare, but more often seen in
southeastern US
 Signs: Anorexia, poor growth, weight loss, anemia, reduced disease
resistance (impaired neutrophil function)
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Toxicity is rare – ruminants can tolerate 100x NRC req.
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Supplement with mineral mixtures
Forage grown in lower pH soil will uptake more cobalt
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Free-choice mineral supplements are the most common
 Place in high-traffic areas
 1 mineral tub per 40 cows
 Add palatable ingredients when water mineral content is high
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Selecting a commercial supplement
 Specific mineral requirements of the cow
 Relative biological availability of mineral sources
 Daily intake
 Concentrations of minerals already in the diet
Heavy Metal Screen
Arsenic
Cadmium
Copper
Iron
Mercury
Manganese
Molybdenum
Lead
Zinc
Trace Mineral Panel
Calcium
Copper
Iron (unbound)
Magnesium
Potassium
Phosphorous
Sodium
Zinc
Test
Sample
Price
Selenium
Purple Top EDTA Blood
$18 ea
10g Liver
$24 ea
Trace Mineral Panel
Royal Blue Top EDTA/Heparin
$18 ea
Heavy Metal Screen
10g Liver
$32 ea