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MINERALS REQUIRED IN LIVESTOCK DIETS. Major minerals (Required in large quantities) Beef Dairy Swine Chicken Finishing Cow Dry Lactating Finishing Sow Broiler Layer Ca, % .5 .15-.3 .6 .8 .6 .75 .8 3.5
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MINERALS REQUIRED IN LIVESTOCK DIETS • Major minerals (Required in large quantities) BeefDairySwineChicken FinishingCowDryLactatingFinishingSowBroilerLayer Ca, % .5 .15-.3 .6 .8 .6 .75 .8 3.5 P, % .2 .12-.23 .3 .4 .5 .6 .8 .8 Mg, % .10 .12 .25 .3 .04 .04 .05 .05 Na, % .06 .08 .15 .25 .10 .15 .15 .15 Cl, % - - .25 .30 .08 .12 .15 .15 K, % .6 .6 1.0 1.5 .23 .20 .4 .4 S, % .15 .15 .2 .26 - - - - • Minor minerals (Required in very small quantities Fe, ppm 30 50 100 100 60 80 80 45 Cu, ppm 10 10 20 20 4 5 8 2 Zn, ppm 30 30 80 70 60 50 50 35 Mn, ppm 20 40 50 50 2 10 60 35 I, ppm .50 .50 .60 .60 .14 .14 .35 .30 Co, ppm .10 .10 .30 .20 - - - - Se, ppm .10 .10 .30 .30 .15 .15 .15 .10 Mo Cr
Minerals are often overfed • Levels of minerals commonly fed in industry to swine MineralLevel fed, % of requirement Ca 160-190 P 140-150 Mg 400-500 Na 147-190 K 390-423 Fe 470-776 Cu 440-667 Zn 298-334 Mn 770-3100 • Reasons for overfeeding of minerals • High levels in feeds • Supplementation to provide safety margin • No consideration of mineral bioavailability • Free choice feeding of trace mineral salt • Use of Cu and Zn salts as growth promotants for swine and poultry Dose, ppm Cu 100-250 Zn 2000-4000
Utilization rates of most minerals are low Utilization rateExcretion rate (% of intake) Ca 30-50 50-70 P 20-50 50-80 Mg 15-30 70-85 Na 10-25 75-90 K 5-20 80-95 Fe 5-30 70-95 Cu 5-30 70-95 Zn 5-30 70-95 Mn 5-10 90-95 • Factors mineral utilization rates • Mineral sources • Organic mineral (Chelates) > SO4 or CO3 salts > oxides • Level fed • Low levels > high levels • Interactions with other minerals • High K reduces Mg absorption • High Zn reduces Cu absorption • Low Cu reduces Fe absorption • Processing • Grinding increases mineral absorption • Age and nutritional status of animals • Young animals absorb minerals better than adults
All minerals are toxic to animals if fed in excess • Maximum tolerable concentrations BeefDairySwinePoultrySheep Ca, % 2 2 1 .4-1.2 2 P, % 1 1 1.5 .8-1.0 .6 Mg, % .4 .5 .3 .3 .5 NaCl, % 4 4 8 2 9 K, % 3 3 2 2 3 S, % .4 .4 - - - Fe, ppm 1000 1000 3000 1000 500 Cu, ppm 100 100 250 300 25 Zn, ppm 500 500 1000 1000 300 Mn, ppm 1000 1000 400 2000 1000 Mo, ppm 5 10 20 100 10 I, ppm 50 50 400 300 50 Co, ppm 10 10 10 10 10 Se, ppm 2 2 2 2 2 Cr, ppm 1000 1000 1000 1000 1000 • Causes of toxicities • Oversupplementation • Poor formulation and/or mixing • Wrong feeds fed to wrong species • High concentrations in feedstuffs
Examples • High K forages (associated with overfertilization) • Health effects • Milk fever A calcium deficiency occurring to dairy cows in early lactation. Results in tetany and death, if untreated. Caused by overfeeding cations, particularly K, during the dry period. Prevents resorption of Ca from bone. • Grass tetany A Magnesium deficiency occurring to animals grazing lush, heavily fertilized grass pastures in the spring. Results in tetany and death, if untreated. Caused by low Mg content of lush forage and inhibition of Mg absorption by high levels of K and N. • High Se forages • Causes • High Se soils in western U.S. • Plant species that accumulate Se • Health effects • Se toxicity Lameness Blind staggers (Labored breathing and ataxia (loss of coordination) • Not yet associated with manure application
CONCERNS WITH EXCESS MINERALS IN SOILS • In soils, most minerals act like P • Minerals bind to soils high in clay or organic matter • Particularly occurs at pH>6 • Occurs particularly near soil surface • Minerals move to water sources with soil erosion • Minerals do not bind to soils that are high in sand or have a low pH • Travel with infiltrating water into ground water sources • Most minerals have limited bioavailability to plants • < 40% • Results in accumulation of trace minerals in soils • Example: • In areas where swine manure has been heavily applied in North Carolina: soil Zn increased 4 times soil K increased 2 times soil Cu increased 3 times • Concern • Once trace minerals have accumulated in the soil, they’re difficult to remove.
Environmental effects of excessive application of manure minerals • Minerals of most concern • P, NaCl, K, Cu, Zn • Effects • Toxic to plants • NaCl, Cu, Zn, Mn • Detrimental or toxic to animal health • May enter water resources with soil erosion or water infiltration
METHODS TO LIMIT MINERAL EXCRETION IN MANURE • Use of precision nutrition of minerals • Limit safety margins when feeding minerals • Utilize mineral sources with high bioavailability • Must balance for available minerals rather than total minerals • Balance for individual minerals rather than using complete trace mineral premixes • Requires rapid feed analysis • Limit use of free choice trace mineral salt • Utilize phase feeding • Utilize separate sex feeding • Limit feed waste