Vitamins in Ruminants
Vitamins
• 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
Fat soluble
Vitamins A, D, E and K
Water soluble
Thiamine, 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
Important
1. Some vitamins must be supplemented in the diet
2. Several aspects of vitamin nutrition unique to
ruminants
3. Likely will be more important:
• As productivity of ruminants is increased
• With increased confinement of animals
References
1. Chapter 7 Dairy NRC 2001
2. 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 diets
High producing dairy cows sometimes benefit
from supplementation with B vitamins
Mixtures of biotin, niacin, riboflaven, panothenic
acid, thiamin, and B12
Inadequate Dietary Vitamin Intakes
• Low concentrations in feeds
Harvesting and agronomic effects
• Processing and storage effects
Humidity, 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
Vitamin Heat Oxygen Light Humidity
pH
7
+
>7
+
+
-
A
-
-
-
-
<7
-
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 rumen
Amprolium blocks absorption
Sulfur may destroy thiamin in the rumen
Situations for Supplementing Vitamins
Situation
Forage, long storage
Weather damaged forage
Residue crops
Heat damaged forage
Frost damage corn silage
High grain feeding
Housed indoors
Milk or replacer diet
Stress periods
Oxidized favor in milk
Extend case life of meat
Improve tenderness beef
---Dairy--A
D
E
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
---Beef--A
D
E
X
X
X
X
X
X
X
X
X
X
X
X
X
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 feeds
Mature - drought pastures
Long stored feeds
Sunlight, air, high temperatures
Heavily processed feeds
Some destruction of vitamin A in the rumen
Increases when concentrates are fed
Forage diets 20%
Grain diets up to 70%
-Carotene
Provitamin A found in many plants
Mostly in the vegetative parts of plants
Decreases as plants mature
Decreases with time in storage
Some destruction in the rumen (0 to 35%)
Converted to retinol by enzymes in intestinal
mucosal cells
Some absorption of -carotene
Ruminants do not efficiently convert carotene
to vitamin A
1 mg carotene = 400 IU vitamin A
Vitamin A
Deficiency
Reduced feed intake - slow growth
Rough hair coat
Edema of joints and brisket
Watery eyes
Night blindness
Retinol needed for synthesis of rhodopsin
Low conception
Still births
Function of immune system
Vitamin A
• Functions
– Normal night vision
– http://www.blackwellpublishing.com/matthews/
rhodopsin.html
Vitamin A
Requirements
Cattle
Growing
Pregnant beef cows
Pregnant dairy cows
Lactating cows
Sheep
Growing lambs
Gestating ewes
Lactating ewes
IU/kg feed DM
2,200
2,800
4,000
3,900
1,500
3,300
2,700
Vitamin A
Requirements
Dairy cattle
Growing: 80 IU/kg body wt
Adult: 110 IU/kg body wt
Supplemental Vitamin A (retinol)
1 IU of Vit A activity =
0.344 ug of all-trans retinyl acetate
0.550 ug all-trans retinyl palmitate
Vitamin A – When to Supplement?
Carotene content of feeds is variable and usually
unknown
Cost of supplemental vitamin A is low – so usually
should supplement
Exception is animals grazing green forages
Should 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 D
1. Ergocalciferol (Vitamin D2) - found in plants
2. 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 animal
Kindney
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 hormone
secretion
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 DM
All beef cattle
275
Growing lambs
185
Gestating ewes
216
Lactating ewes
148
Lactating dairy
30 IU/kg body wt
Dry 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 sunlight
as sources of vitamin D
Vitamin D Toxicity
Safe feeding levels:
A few days - 25,000 IU/kg feed
60 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 fever
20 million IU/d starting 3 to 5 days before calving
continuing through the fist day postpartum
Improve tenderness of beef
Assumption:
Increased blood and muscle Ca increases
activity of calpains, enzymes in muscle
that degrade muscle myofibrils
Observations:
Blood Ca increased
Increased degradation of myofibrils
Reduced force to shear muscle
Vitamin E
-tocopherol is the most common form of
vitamin 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 calving
80 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 cows
20 IU/kg feed DM
Needs to be increased when poor quality
forage is fed or if feeds have low Se content
Supplement Se if low in soils
3 to 5 mg /d for dry cows
6 to 8 mg/d for lactating cows
Vitamin E - Beef & Sheep
Requirement
IU/kg feed DM
All beef cattle
15 to 60
Pregnant and lactating cows 20
Growing heifers
25
All sheep
15
Related to adequacy of selenium
Vitamin E not transferred across placenta to fetus
Dependent on colostrum for dietary source
Feedlot cattle
Feed 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 group
of 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 lameness
Uncontrolled bleeding – hematoma of tissues
Other Water Soluble Vitamins
Not required in diet of ruminants
Ruminants with functional rumen obtain water
soluble vitamins from the digestive tract
Niacin -------- Supplementation may benefit high
Biotin ---producing animals
Folic acid --Vitamin B12 – Synthesized in rumen if Co present,
not present in feeds
Vitamin C - Not synthesized in cattle until about 3 wks
Riboflavin
Pyridoxine
Pantothenic acid
Choline
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 cows
Biotin - May benefit herds with high incidence of
hoof lesions
Folic acid - Might increase milk production
Cobalt - B12 - (methylmalonyl CoA mutase) utilization
of propionate, foliate metabolism, milk yield
B-vitamins - immune function of stressed cattle
Thiamin
1. Adequate quantities normally produced by the bacteria
in the rumen
2. Inadequate thiamin
Thiaminase and thiamin antimetabolites produced
in 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