Vitamins in Ruminants

• Organic compounds required in trace amounts for biological processes

• Vital amine • Fat soluble

– A, D, E, and K

– Absorbed with lipids

• Water soluble– C, B family

Vitamins

Vitamins

Fat solubleVitamins A, D, E and K

Water solubleThiamine, niacin, riboflavin, pyridoxine,pantothenic acid, biotin, folic acid, vitamin B12, vitamin C, choline

Water soluble vitamins and vitamin K synthesized in the rumen or in body tissues

Dietary requirements: Vitamins A, D, and E

Vitamin Nutrition of Ruminants

Important1. Some vitamins must be supplemented in the diet2. Several aspects of vitamin nutrition unique to

ruminants3. Likely will be more important:

• As productivity of ruminants is increased• With increased confinement of animals

References1. Chapter 7 Dairy NRC 20012. Chapter 6 Beef NRC 1996

Vitamin Requirements of Ruminants

• Ruminants require the same vitamins as monogastric animals at cell level• Prior to rumen development young ruminants require dietary sources of vitamins

• Colostrum and milk• Concentration of vitamins in colostrum is greater

than in milk• Calves need to be fed vitamins if they are being fed milk replacers with nonmilk protein

Vitamin Requirements of Ruminants

Mature ruminants have dietary requirement for:Vitamins A, D, and E

Vitamin D in feed or from UV exposure

B vitamins usually not supplemented in ruminant dietsHigh producing dairy cows sometimes benefitfrom supplementation with B vitamins

Mixtures of biotin, niacin, riboflaven, panothenicacid, thiamin, and B12

Inadequate Dietary Vitamin Intakes

• Low concentrations in feedsHarvesting and agronomic effects

• Processing and storage effectsHumidity, heat, light, pH, minerals, pelleting

• Reduced feed intake• Bioavailability

B-vitamins affected more than fat soluble• Level of production

Increased grain intake, increased feed intake,increased rate of passage, reduced rumen function

• Rearing in confinement out of sunlight• Stress and disease

Decreased feed intake, increased requirement

Factors Influencing Vitamin Stability

pHVitamin Heat Oxygen Light Humidity< 7 7 > 7

A - - - - - + +

D - - - - + + -

E -(+) -(+) -(+) -(+) +(+) +(+) +(+)

K + + - - - + -

Thiamin - - + - + - -

+ = stable - = unstable ( ) = tocopheryl acetate

Circumstances Affecting Vitamin Nutrition

Vitamin antagonists of importance to ruminants• Dicumarin (Dicumarol)

Found in moldy sweet clover - Blocks the action of vitamin K (Depresses formation of thrombin) Animals can bleed internally• Rancid fats

Destroys vitamins A, D, and E• Thiamin antagonists

Thiaminase - may develop in the rumenAmprolium blocks absorptionSulfur may destroy thiamin in the rumen

Situations for Supplementing Vitamins ---Dairy--- ---Beef---

Situation A D E A D E Forage, long storage X X Weather damaged forage X X X Residue crops X X X X Heat damaged forage X X Frost damage corn silage X X High grain feeding X X X X Housed indoors X X Milk or replacer diet X X X X X X Stress periods X X X X X Oxidized favor in milk X Extend case life of meat X X Improve tenderness beef X X

Vitamin A (Retinol)

Vitamin of most practical importance in ruminant feeds.Deficiency most likely:

High concentrate feeds (low forage)Large amounts of fermented feedsMature - drought pasturesLong stored feeds

Sunlight, air, high temperaturesHeavily processed feeds

Some destruction of vitamin A in the rumenIncreases when concentrates are fedForage diets 20% Grain diets up to 70%

-Carotene

Provitamin A found in many plantsMostly in the vegetative parts of plantsDecreases as plants matureDecreases with time in storageSome destruction in the rumen (0 to 35%)Converted to retinol by enzymes in intestinalmucosal cellsSome absorption of -carotene

Ruminants do not efficiently convert caroteneto vitamin A

1 mg carotene = 400 IU vitamin A

Vitamin A

DeficiencyReduced feed intake - slow growthRough hair coatEdema of joints and brisketWatery eyesNight blindness

Retinol needed for synthesis of rhodopsinLow conceptionStill birthsFunction of immune system

• Functions– Normal night vision– http://www.blackwellpublishing.com/matthews

/rhodopsin.html

Vitamin A

Vitamin A

RequirementsCattle IU/kg feed DM

Growing 2,200Pregnant beef cows 2,800Pregnant dairy cows 4,000Lactating cows 3,900

SheepGrowing lambs 1,500Gestating ewes 3,300Lactating ewes 2,700

Vitamin A

RequirementsDairy cattle

Growing: 80 IU/kg body wtAdult: 110 IU/kg body wt

Supplemental Vitamin A (retinol)1 IU of Vit A activity =

0.344 ug of all-trans retinyl acetate0.550 ug all-trans retinyl palmitate

Vitamin A – When to Supplement?

Carotene content of feeds is variable and usuallyunknown

Cost of supplemental vitamin A is low – so usuallyshould supplement

Exception is animals grazing green foragesShould be consuming adequate carotene

Increased exposure to infectious pathogens

Times when immunocompetence may be reduced

Vitamin A Reserves in the Body

• Vitamin A stored in the liver when intake of vitamin A or carotene is high

• Vitamin A in the liver has about 4 week half life

• Should not depend on more that 2 to 4 months of protection from storage of vitamin A in the liver

• Ruminants have a high tolerance for vitamin A Will tolerate 66,000 IU/kg feed

Vitamin D1. Ergocalciferol (Vitamin D2) - found in plants2. Cholecalciferol (Vitamin D3) - found in animals Photochemical conversion in skin:

7-dehydrocholesterol Cholecalciferol

Liver (Sequesters Vit D3) Vit D3 25-hydroxy-vit D3

• Circulating form of Vit D3

• Blood concentrations of 25-hydroxy-vit D3

indication of vitamin D status of the animalKindney 25-hydroxy-vit D3 1, 25-dihydroxy-vit D3

• Active form of vitamin D• Active on skeleton and intestine• Potentiates action of parathyroid hormone

Vitamin D from UV exposure

Active Vit D3

Vitamin D3

Low blood Ca (or P) increases parathyroid hormonesecretion

Parathyroid hormone increases production of• 1,25-dihydroxy-vit D3 in kidney• Increases resorption of bone Ca and P

Involved in:• Absorption of Ca and P and mobilization of Ca and P from bone• Regulation of blood Ca and P• Immune cell function• Reproduction of males and females

Vitamin D - Ruminants

Deficiency• Rickets in calves• Swollen and stiff joints• Reduced feed intake• Tetany• Weak bones

Vitamin D can be toxic• High blood Ca• Calcification of soft tissues• Loss of appetite

Vitamin D not stored in the body in any quantity

Vitamin D - Requirements

Requirement IU/kg Feed DMAll beef cattle 275Growing lambs 185Gestating ewes 216Lactating ewes 148Lactating dairy 30 IU/kg body wtDry pregnant cows 30 IU/kg body wt

• Generally recognized as more than required

Animals fed sun cured hays and/or kept in sunlight have limited needs for supplemental vitamin D

Dairy NRC does not give credit to feed and sunlightas sources of vitamin D

Vitamin D Toxicity

Safe feeding levels:A few days - 25,000 IU/kg feed60 days - 2,200 IU/kg feed

Toxicity• Loss of appetite• Weight loss• Reduced rumination• Depression• Widespread calcification of soft tissue

Kidneys, heart, pancreas, lymph glands, lung alveoli• Inflammation• Demineralization of skeletal system

Feeding Mega Doses of Vitamin D

Prevent milk fever20 million IU/d starting 3 to 5 days before calvingcontinuing through the fist day postpartum

Improve tenderness of beefAssumption:

Increased blood and muscle Ca increasesactivity of calpains, enzymes in musclethat degrade muscle myofibrils

Observations:Blood Ca increasedIncreased degradation of myofibrilsReduced force to shear muscle

Vitamin E

-tocopherol is the most common form ofvitamin E in feeds

• Vit E content of feeds is highly variable• Vit E decreases in forages with drying and storage

Most fresh forages excellent source of Vit E• Most grains have low concentrations of Vit E• Heat treatment destroys most of the Vit E

Supplemental form of vitamin E is DL- -tocopherol• The esterified form is more stable than the alcohol• Rumen metabolism is minimal•1 IU = 1 mg DL- -tocopherol

Vitamin E

Functions as an antioxidant and involved in• Maintenance of cell membranes• Immunity• Reproduction

Deficiency• White muscle disease• Weak muscles• Retained placenta• Reduced reproduction• Reduced disease resistance

Toxicity not demonstrated in ruminants

Vitamin E not extensively stored in the body

Vitamin E - Dairy - 2001

1. Dry cows 60 days before calving80 IU/kg feed DM• Based on reduction of mastitis and immune function• Higher amounts needed for fetus and to increase

concentration in colostrum

2. Lactating cows20 IU/kg feed DM

Needs to be increased when poor qualityforage is fed or if feeds have low Se content

Supplement Se if low in soils3 to 5 mg /d for dry cows6 to 8 mg/d for lactating cows

Vitamin E - Beef & Sheep

Requirement IU/kg feed DMAll beef cattle 15 to 60Pregnant and lactating cows 20Growing heifers 25All sheep 15

Related to adequacy of selenium

Vitamin E not transferred across placenta to fetusDependent on colostrum for dietary source

Feedlot cattleFeed 500 IU/day for 100 days.Extend shelf life of beef cuts in the sales case

Vitamin K

Vitamin K is a generic term describing a groupof quinone compounds

• Phylloquinone (vitamin K1) Found in chloroplasts of plants

• Menaquinone (vitamin K2) Synthesized by rumen bacteria

• Menadione (vitamin K3) Synthetic form used for supplementing vit K

Vitamin K

Required for synthesis of four blood clotting factors• Prothrombin, factors VII, IX, and X• Involved in blood clot formation

No established supplemental requirement for ruminants• Microbial synthesis and vit K in feeds

Deficiency limited to:• Cattle consuming moldy sweet clover have prolonged clotting of blood - “sweet clover disease”• A fungus produces dicoumarol that is a metabolic antagonist of vitamin K

Stiffness and lamenessUncontrolled bleeding – hematoma of tissues

Other Water Soluble VitaminsNot required in diet of ruminants

Ruminants with functional rumen obtain watersoluble vitamins from the digestive tract

Niacin -------- Supplementation may benefit highBiotin ---- producing animalsFolic acid ---

Vitamin B12 – Synthesized in rumen if Co present, not present in feeds

Vitamin C - Not synthesized in cattle until about 3 wks

RiboflavinPyridoxinePantothenic acidCholine

Supplementation of B Vitamins

1. Prevent overt deficiency symptoms• Probably occur only in calves fed milk replacers

2. Prevent subclinical deficiencies• Optimum production• Impact of stress on immune system

Niacin - May benefit early lactation cowsBiotin - May benefit herds with high incidence of hoof lesionsFolic acid - Might increase milk productionCobalt - B12 - (methylmalonyl CoA mutase) utilization of propionate, foliate metabolism, milk yieldB-vitamins - immune function of stressed cattle

Thiamin

1. Adequate quantities normally produced by the bacteria in the rumen2. Inadequate thiamin

Thiaminase and thiamin antimetabolites producedin ruminants fed rapidly fermented diets

• Infrequently polioencephalomalacia (PEM), a disorder of the central nervous system develops

• Retracted head, weakness, collapse, blindness are symptoms

• Respond to administration of thiamin