1. V ITAMINS IN R UMINANTS

2. V ITAMINS Vital amine Fat soluble A, D, E, and K Absorbed with lipids Water soluble C, B family

3. V ITAMINS Fat soluble Vitamins A, D, E and K Water soluble Thiamine, niacin, riboflavin, pyridoxine, pantothenic acid, biotin, folic acid, vitamin B 12, vitamin C, choline Water soluble vitamins and vitamin K synthesized in the rumen or in body tissues Dietary requirements:

4. V ITAMIN N UTRITION OF R UMINANTS 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

5. V ITAMIN R EQUIREMENTS OF R UMINANTS 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

6. V ITAMIN R EQUIREMENTS OF R UMINANTS 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 B 12

7. I NADEQUATE D IETARY V ITAMIN I NTAKES Harvesting and agronomic 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

8. C IRCUMSTANCES A FFECTING V ITAMIN N UTRITION Vitamin antagonists of importance to ruminants Found in moldy sweet clover - Blocks the action of vitamin K (Depresses formation of thrombin) Animals can bleed internally Destroys vitamins A, D, and E Thiamin antagonists Thiaminase - may develop in the rumen Amprolium blocks absorption Sulfur may destroy thiamin in the rumen

9. S ITUATIONS FOR S UPPLEMENTING V ITAMINS

10. V ITAMIN A (R ETINOL ) 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%

11.  -C AROTENE 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

12. V ITAMIN A Deficiency 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

13. V ITAMIN A Requirements Cattle IU/kg feed DM Growing2,200 Pregnant beef cows2,800 Pregnant dairy cows4,000 Lactating cows3,900 Sheep Growing lambs1,500 Gestating ewes3,300 Lactating ewes2,700

14. V ITAMIN 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

15. V ITAMIN D 1.Ergocalciferol (Vitamin D 2 ) - found in plants 2.Cholecalciferol (Vitamin D 3 ) - found in animals Photochemical conversion in skin: 7-dehydrocholesterolCholecalciferol Liver (Sequesters Vit D 3 ) Vit D 3 25-hydroxy-vit D 3 Circulating form of Vit D 3 Blood concentrations of 25-hydroxy-vit D 3 indication of vitamin D status of the animal Kindney 25-hydroxy-vit D 3 1, 25-dihydroxy-vit D 3 Active form of vitamin D Active on skeleton and intestine Potentiates action of parathyroid hormone

16. V ITAMIN D FROM UV EXPOSURE Active Vit D 3

17. V ITAMIN D 3 Parathyroid hormone increases production of 1,25-dihydroxy-vit D 3 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

19. V ITAMIN D - R UMINANTS Deficiency 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

20. V ITAMIN D - R EQUIREMENTS Requirement IU/kg Feed DM All beef cattle275 Growing lambs185 Gestating ewes216 Lactating ewes148 Lactating dairy30 IU/kg body wt Dry pregnant cows30 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

21. V ITAMIN D T OXICITY 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

22. F EEDING M EGA D OSES OF V ITAMIN 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

23. V ITAMIN E 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

24. V ITAMIN E 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

25. V ITAMIN E - D AIRY - 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

26. V ITAMIN E - B EEF & S HEEP Requirement IU/kg feed DM All beef cattle 15 to 60 Pregnant and lactating cows20 Growing heifers25 All sheep15 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

27. V ITAMIN K Phylloquinone (vitamin K 1 )  Found in chloroplasts of plants Menaquinone (vitamin K 2 )  Synthesized by rumen bacteria Menadione (vitamin K 3 )  Synthetic form used for supplementing vit K

28. V ITAMIN 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 delayed 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

29. O THER W ATER S OLUBLE V ITAMINS N OT 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

30. S UPPLEMENTATION OF B V ITAMINS 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 - B 12 - (methylmalonyl CoA mutase) utilization of propionate, folate metabolism, milk yield B-vitamins - immune function of stressed cattle