Animal Science 429: Sheep
Vitamin and Mineral Nutrition
Immunity
Danielle Pogge
Outline
• Immunity background
• Antioxidants and immunity
• Minerals and related disorders
Immunity background
• Health/Immunological issues in the industry:
– Internal parasites/worms
– Digestive disorders
– Abortion diseases
– Foot rot
• Sheep Normals:
– Body Temperature: ~102°F
– Respiration rate: ~20/min
– Heartbeat: ~75/min
Maintain Healthy Sheep
• Management:
– Buy healthy sheep
– Minimize stressors
• Adequate space, nutrition, air quality, social
– Biosecurity measures:
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•
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Isolate new sheep
Monitor visitors (boot covers, etc)
Clean stock trailers and scales
Shows = place to pick up diseases
Innate vs. Adaptive
• Innate immunity = No Memory and Fast
– Non-specific!
– Surface barriers: skin and mucous membranes
– Internal defense: fever, phagocytes, NK cells,
inflammation, antimicrobial proteins
• Adaptive immunity = Memory but delayed
– Antigen specific!
– Developed over lifetime:
• Humoral immunity: B cells (bone marrow)
• Cellular immunity: T cells (thymus)
• Can’t have Adaptive without Innate!
The Immune Response
• Initiation:
– Fever, swelling, aching, vasodialation
– Energy repartitioning to synthesize acute phase
proteins (inflammatory mediators)
• Reduction in production efficiency
– Activation of Adaptive immune response
– Immunological memory
• Resolution:
– Release of anti-inflammatory mediators (TGF-B and
IL-10)
– Repair tissues (ROS damage)
– Down-regulate pro-inflammatory signals
Vaccination Response
• Immunological
Memory
– Initial response (1°)
delayed
– Second exposure (2°) =
Rapid response
– Mobilize lymphocytes
Immunity and Production
• Influence of an immune response on production:
– Hypermetabolic = Inefficient!
• Decrease anabolic processes, focused on catabolism
– Mobilization of nutrients for immune support
» Protein = cytokine production not growth/maintenance
» Lipid = reduction in adipose mass
• Immune response reactions are expensive (calories and
protein) for producers
– Reduction in growth and production
» Longer days on feed (finishers)
» Loss of lambs or ewes (abortions/death)
– Increase susceptibility to secondary infections
• GI and lungs targets (mucosal surfaces)
Antioxidants and Immunity
• Antioxidants = Prevention of Oxidative Stress
– Defined as: molecules that prevent cell damage against free radicals
and are critical for maintaining optimum health
• Common antioxidants:
– Vitamins (A, C, D, E) and Minerals (Cu, Zn, Mn, Se, Fe)
• Free Radicals/ROS
– Normal respiration/metabolism (mitochondria)
– Infection (mode of killing = release ROS)
– UV exposure
• Oxidative Stress (Pro-oxidants vs. Antioxidants)
– Decreased cell function (apoptosis) and gut integrity = increase
pathogen entry to system = Immune reaction!
Vitamins and Immunity
• Vitamin A (beta-carotene):
– Epithelial cell generation (gene functions)
• Epithelial cell barrier function (host defense)
– Development/differentiation of lymphocytes
– Role in activation of T-lymphocytes
• Vitamin D:
– Enhanced bacterial killing by macrophages
• Vitamin E and C:
– ROS scavengers
Trace Minerals and Immunity
• Cu, Zn, Mn, Fe, Se
– SOD
– Catalase
– GSH-Px
• Immune response
– Activation of
macrophages
– Killing mechanism =
release ROS
– Increase oxidative
damage/stress
Vitamin and Mineral
Requirements
Factors influencing availability
• Bioavailability:
– A measure of the use of a mineral/vitamin to
support a physiological function (Dr. Hansen)
• Influencing factors:
– Age, stage of production, gender, species,
genetics, pH/solubility of mineral, gut
integrity/immune status, antagonisms, stress,
heat, soil status, storage….
Vitamins A, D, E, C
• Sources:
– A: forages (carotenoids)
– D: Sun exposure (cholesterol  1, 25 OH-D3)
Plants (D2)
– E: Leafy plants (only produced by plants)
– C: Glucose  Vitamin C (liver)
• Deficiency:
– A: decreased growth, retained placenta, bone
malformation, night blindness
– D: rickets (young), osteomalacia (older)
– E: white muscle disease, stiffness, arched back
– C: scurvy (collagen malformation)
Biotin
• B vitamins: produced by bacteria in rumen
• Functions:
– Involved in CHO, lipid, and protein metabolism
• Keratin production (dermis = skin, hair, hooves, etc)
• Deficiency:
– High concentrate diets may decrease biotin production
• Soft hooves that easily crack
• Supplementation:
– Study: 0.21, 3.26, 5.25mg
– Hoof health
• Rams?
Bampidis et al. (2006) Animal Feed Science and Technology
Mineral classifications:
• Macros = required in
large amounts (%)
– Ca, P, K, S, Na, Mg, Cl
• Micros = required in
small amounts
(ppm/ppb)
– Cu, Fe, Zn, Mn, Se, I,
Co
Calcium (Ca) & Phosphorus (P)
• Source:
– Forages = Ca high, P low
– Cereal grains = P high, Ca low
• Supplement Sources:
– Limestone (Ca)
– Dicalcium phosphate (Ca, P)
• Requirements (based on percent diet):
– Ca: P Ratio: 1.5-2: 1
– 0.2 -0.82% Ca (age dependent)
• No toxic level (homeostasis, excretion to urine)
– 0.16 – 0.38% P
• Phytate decrease availability of Ca, P, Mg
– Ruminants microbes = phytase (break phytate)
• Functions:
Ca and P
– Bone mineralization (Hydroxyapatite)
– Ca:
• Muscle contraction and degradation
– Protease calpain
• Resting membrane potential (K)
– P:
• High energy bonds (ATP)
• Phospholipids (membranes)
• Deficiency
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–
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Rickets, osteomalacia, osteoperosis
Kidney stones (urinary calculi)
Antagonist with other minerals: Zn, Fe, Mg
Decreased growth and reproduction
Urinary Calculi
• Male sheep (wethers and rams)
– Small urinary tract design
• Kidney stone types:
– Phosphates, Ca oxalates; Silica
• Cause:
– High concentrate diets
• Low Ca, High P
• Prevention:
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–
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Adequate water intake
Salt (increase water intake)
Ammonium Cl or sulfate
Adequate Ca:P ratio 1.5-2: 1
Do not add P to the diet
Electrolytes
• Sodium (Na), Potassium (K), Chloride (Cl), Magnesium (Mg):
– Salt (Na, Cl); Ammoninum Chloride (Cl); Mg oxide
• Requirement:
– 0.09 - 0.18% Na
– 0.5 – 0.8 % K
– 0.12- 0.18% Mg
• Functions:
– Action potential (depolarization)
• Nerve conduction and muscle contraction (K)
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Osmotic pressure (electrolytes)
Nutrient Absorption (Na), HCl production (Cl)
Acid-Base Balance
Enzymes for CHO and protein synthesis
Associated with P (Mg)
• Phospholipids and enzyme stabilization, DNA/RNA backbones
• Deficiency/Toxicity:
– Reduced growth, production, and feed efficiency
– Muscle weakness (tetany)
Grass Tetany
• Hypomagnesia; “Grass staggers”
• Symptoms:
– Sensitivity to touch, trembling of facial muscles
– Stiff movements, tetanic spasms of all limbs
• Cause:
– Low blood Mg and high K
• Spring grass = low Mg and high K
• Mineral imbalance
• High K inhibits Mg absorption
• Prevention:
– Supplement ewes on pasture with Mg
Sulfur (S)
• S in feeds:
– S-AA, DDGS, sulfates (supplement)
• Requirement:
– 0.14- 0.26 %
• Microbe health (S-AA and S-B vitamins)
• Functions:
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–
–
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Component of S AA (Met, Cysteine, Cystine, Taurine)
Component of B vit (Thiamin and Biotin)
Wool component (curling/crimping—disulfide bonds)
Redox reactions
• Disulfide bonds—sulfhydryl groups
• Glutathione synthesis
– Detoxify
Sulfur
• Deficiency:
– Decreased digestibility and protein synthesis
– Reduced wool growth or shedding growth
• Toxicity:
– High S diets (EtOH byproducts) or high S water
• H2S production in rumen = toxic
– Reduced intake and gain
– Polioencephalomalacia (PEM)
• Brain lesions and blindness
• Treat: dexamethasone and thamine
– Gradual ration changes
– Provide roughage (keeps pH up)
Trace Minerals: Copper (Cu)
• Requirements:
– Limited tolerance for Cu (7-11 ppm, Toxic: 25
ppm)
– Cattle and swine feed high in Cu
– Breed susceptibility
• Texel = poor at absorbing Cu
• Functions:
– Enzymes (collagen formation and immunity)
• Cu-Zn SOD– remove ROS
– Keratin (wool) production
Copper (Cu)
• Deficiency:
– Cause: dietary antagonisms (Mo, S) –thiomolybdates
– Decreased immunity
• SOD, cytochrome oxidase
– “Sway-back”
• Brittle bones and stringy/loss of wool
• Toxicity:
– Accumulation of excess Cu
– Symptoms:
• Lethargic, anemic, thirst, red urine, jaundice
– Death = 1-2 d after symptoms appear
• Treatment
– Prevention preferred (do not supplement Cu)
– Drench of 10 - 50 mg ammonium molybdate and 0.5- 1.0 g Na
sulfate
Zinc (Zn)
• Requirements:
– 20 - 30 ppm (max = 750 ppm)
• Functions:
– Enzyme cofactor
• Nucleic acid, protein, and CHO metabolism
– Immune component
• SOD with Cu
• Deficiency:
– Reduced growth, feed intake, feed efficiency
– Impaired immune response
– Foot lesions
• Foot Rot Treatment
– Zn sulfate
Selenium (Se)
• Requirement: narrow window– 0.1 – 0.3 ppm
– 2 ppm = toxic
• Functions:
– Immunity (GSH-Px: blood)
– Remove ROS – decrease oxidative stress/damage
• Deficiency:
– White Muscle Disease
• Prevent: Selenium/Vitamin E injection
– Decrease repro performance
– Increase lamb mortality
• Toxicity:
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Soil status = in forage
Reduced gain and intake
Lameness
Loss of hair/wool
White Muscle Disease
• Symptoms:
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Stiff rear legs/arched back
Sudden death
Aspiration pneumonia
Poor suckling
• Se required for tongue muscles
– Decreased reproduction
• Prevention:
– Vitamin E/Se injection prior to lambing
– Provide adequate vitamin E to ewes
• High grain = low E
• Milk is primary source of E to newborns
Iodine (I)
• Requirement:
– 0.1 to 0.8 ppm; 50 ppm = toxic
• Goiter
– Symptoms:
• Enlarged thyroid
• Poor wool coat at birth
• Low survival
– Prevention:
• Iodized salt
• Keep in mind goitergens (kale, etc.)
Summary
• Vitamins and minerals are essential for many
processes in the body
• Deficiencies and toxicities can result in a
reduction in performance
• Proper management can eliminate a lot of
disorders