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Mineral Nutrition for Ruminants. Major Minerals. Major (macro) minerals Ca, P, K, Mg, Na, Cl, S Included as % in diet Functions. Trace Minerals . Trace (micro) minerals Cobalt, copper, iodine, iron, manganese, molybdenum, selenium and zinc all required Chromium-no established requirement
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Major Minerals • Major (macro) minerals • Ca, P, K, Mg, Na, Cl, S • Included as % in diet • Functions
Trace Minerals • Trace (micro) minerals • Cobalt, copper, iodine, iron, manganese, molybdenum, selenium and zinc all required • Chromium-no established requirement • Included as ppm or ppb in diet • Function
Milk Fever Symptoms included lack of appetite and paralysis Treatment is intravenous Ca borogluconate
Milk Fever Prevention • mEq(Na+ + K+) – mEq(Cl- + SO4-) • Normal diet: +20 to +30 mEq/100g diet (electrolyte balance) • Anionic diet: -7 to -25 mEq/100g diet • Induces mild acidosis, which increases tissue responsiveness to PTH • Ca release from bone to serum
Grass Tetany • Fertilizing with K or N make it worse • Symptoms include muscular twitching, collapse, convulsion • Treatment is IV Mg gluconate • Prevent with high Mag mineral (MagOx)
Copper, sulfur and molybdenum • Cu + thiomolybdates insoluble complexes • Thiomolybdates can result in reduced Cu absorption and systemic metabolism NRC, 1996
Copper Toxicosis • 5 ppm Cu • Excessive Cu builds up in RBC, causing Heinz-body formation and methemoglobin production • Can’t bind oxygen-chocolate blood • Release of hemoglobin damages kidneys • Avoid feeding cattle mineral
Copper Toxicosis Treatment • IV methylene blue to control metHb • Copper chelators • Ammonium tetrathiomolybdate • Cu:Mo ratio of 10:1 or less
Sulfur Toxicity in Ruminants • Eructate-reinhale • Toxic in high amounts • Polioencephalomalacia (PEM, brainers)
Polioencephalomalacia (PEM) • Terminology • Polio = • Encephalo = • Malacia = • Clinical signs • Subacute – head pressing, circling, ataxia, staggering, blindness, depression, stupor • Acute – blindness, seizures, comatose • Can be caused by thiamine deficiency, lead or salt poisoning and high sulfur diets
S induced PEM • Does not appear to be caused by thiamine or copper deficiency • No alterations of thiamine or its mono- and diphosphate esters in whole blood, brain, cerebrospinal fluid, or liver (Sager et al., 1990; Gould et al.,1991) • Thiamine treatment can help reduce symptoms • Increase energy availability to the brain • plays a key role in the tri-carboxcylic acid cycle and pentose shunt • Thiamine-supplemented groups also manifested PEM, even though clinical signs were not observed (Olkowski et al., 1992).
Oxidative Stress • Byproduct of cellular respiration • Roles in cell signalling • Dangerous in excess • Species • Hydroxyl • Superoxide • Hydrogen peroxide
Oxidative Stress • Effects • Inactivation of some enzymes (oxidation of metal cofactors)
Antioxidant Capacity • Superoxide anion to hydrogen peroxide • Copper-Zinc SOD-cytosol • Manganese SOD-mitochondria http://en.wikipedia.org/wiki/Superoxide_dismutase
Antioxidant Capacity • Hydrogen peroxide to water and oxygen • Consists of 4 parts, each containing a heme (iron) group
Antioxidant Capacity • Hydrogen peroxide to water • Selenium dependent enzyme-4 selenium atoms per molecule
Iodine • 70-80% of body I- is in thyroid • T4 (thyroxine) • T3 (triiodothyronine)-3 times more active than T4 • Controls rate of energy metabolism in cells
Iodine • Plants have “goitrogens” (goiter creating), block use of iodine • Reduced growth • Impaired reproduction-dead, weak or hairless young
Selenium • Function • Glutathione peroxidase (antioxidant) • Iodothyronine 5’-deiodinase-1 (T4 conversion to T3)
Selenium • Deficiency • Reproductive problems such as retained placenta and low fertility, weak newborns
Cobalt • Rumen microorganisms synthesize B12 from cobalt • B12 dependent enzymes • Methylmalonyl-CoA mutase • Methionine synthetase
Mineral Deficiencies • Severe (clinical signs) • Marginal • Slight reductions in milk • Increased incidence of disease
Deficiencies • Occur because • Presence of antagonist in diet • Low bioavailability of mineral
Mineral Sources • Feedstuffs • Mineral supplements • Goal of supplementation program:
Types of Supplement White salt Protein-molasses block Liquid supplement (molasses, corn steep, to suspend mineral)
Differences among supplements • Amount of mineral provided • Source of mineral used • Level of intake • Salt level (high level to limit) • Amount of carrier-molasses, grain by-products, flavoring agents