Animal Science 429: Sheep

1. Animal Science 429: Sheep Vitamin and Mineral Nutrition Immunity Danielle Pogge

2. Outline • Immunity background • Antioxidants and immunity • Minerals and related disorders

3. 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

4. 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

5. 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!

6. 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

7. Vaccination Response • Immunological Memory • Initial response (1°) delayed • Second exposure (2°) = Rapid response • Mobilize lymphocytes

8. 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)

9. 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!

10. 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

11. 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

12. Vitamin and Mineral Requirements

13. 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….

14. 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)

15. 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

16. 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

17. 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)

18. 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

19. 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

20. 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)

21. 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

22. 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

23. 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)

24. 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

25. Copper (Cu) • Deficiency: • Cause: dietary antagonisms (Mo, S) –thiomolybdates • Decreased immunity • SOD, cytochromeoxidase • “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

26. 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

27. 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

28. 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

29. 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.)

30. 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