Animal Science 429: Sheep

Vitamin and Mineral NutritionImmunity

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: • 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)

Ca and P • Functions: – Bone mineralization (Hydroxyapatite)– Ca:

• Muscle contraction and degradation – Protease calpain

• Resting membrane potential (K)

– P: • High energy bonds (ATP) • Phospholipids (membranes)

• Deficiency – 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: – 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) – 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: – 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: – Soil status = in forage – Reduced gain and intake – Lameness – Loss of hair/wool

White Muscle Disease • Symptoms: – 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