Chapter 6 Livestock Nutrition

1. Chapter 6 Livestock Nutrition Vitamins, Feed Additives and Water

2. Objectives • Describe vitamins and feed additives. • List sources of vitamins and feed additives. • Describe the functions of vitamins, feed additives, and water. • Describe deficiency symptoms caused by lack of vitamin in the ration. • Discuss the effects of feed additives in the ration. • Discuss regulations on the use of feed additives in the ration. • Discuss requirements for vitamins, feed additives and water.

3. Vitamins Defined • Vital to health, only needed in small amounts. • Required for normal growth and and maintenance of animal life. • Only small amounts are needed because they function as catalysts in metabolic processes.

4. Composition • There are 16 vitamins in animal nutrition that are essential. • They all have different chemical compositions. • Different from each other in specific functions, but are grouped together because they are all organic, essential in trace amounts.

5. Naming • During early research, they were designated by the letter of the alphabet in which they were discovered. • Vitamin B was actually a number of different substances, therefore they started using subscripts. • Today they are referred to either by letter designations or chemical names, the latter is used more often.

6. Solubility • Some are soluble in water and fat. • Water soluble include B complex and C. • Fat soluble fats include A, D, E and K. • The solubility of a vitamin is related to its function in metabolism.

7. Ration Considerations • Some vitamins can be synthesized in the body, therefore do not need to be added to a diet. • Fat soluble vitamins can be stored in the animals body, reducing the need for daily supply. • Water soluble cannot be stored therefore need to be supplied on a daily basis.

8. Ration Consideration • Vitamin content of feeds varies with the quality of feed. • A feed may contain an essential vitamin but it may have a low availability in metabolism. • It is generally recommended that vitamin premixes be used at the appropriate levels in livestock feeding to assure a ready supply of essential vitamins are available.

9. Ration Considerations • Specific vitamins have specific functions. • Involved in a number of metabolic processes and deficiency symptoms are an indication that basic metabolic processes in the body have been disturbed.

10. Vitamin A • The product of the conversion in the animal’s body of carotene which is found in feeds. • True vitamin A is not found in feeds. • Because vitamin A is converted from carotene, the carotene is regarded as a precursor of vitamin A. • Beta-carotene is the standard used.

11. Vitamin A • Different animal species covert carotene to vitamin A at different rates. • When the feed source supplied enough carotene, the animal can usually meet its requirements for vitamin A from the diet.

12. Vit A Functions • Normal maintenance of the eyes, membrane tissue, respiratory, digestive, reproductive, nerve, and bone growth.

13. Vit A Deficiency • Night blindness is a symptom of severe vitamin A. • Animals may become permanently blind because of a vitamin A deficiency. • Eye infections and constriction in the optic nerves can be less severe symptoms. • Excessive watering of eyes. Cornea ulcerations are indications of possible vit A deficiency.

14. Vitamin A Deficiency • Keratinization of the epithelial tissue, which causes lowered resistance to infections is common with vitamin A deficiency. • Diarrhea, reduced appetite, poor growth and weight loss are also indicators of vit. A deficiency. • Reproductive problems, poor conception, reduced fertility in males, shortened gestation, retained placenta and still born can also be indicators.

15. Vitamin A Sources • Carotene is found in good quality, fresh, green forages in amounts generally sufficient to supply the needs of livestock. • Green, leafy hays that have been in storage less than one year, legume hays, good qulity grass or legume silages. • Dried sun-cured forages contain less carotene. • Bleached, low quality forages have little carotene content. • Yellow corn is a good source of carotene.

16. Vitamin A Sources • Carotene content of forages in storage is reduced by exposure to the sun and air, high temperature and long storage times reduce content. • Mixing the feeds with oxidizing agents such as some minerals or organic acids will also reduce content.

17. Vitamin A storage • Stored in the liver and fatty tissues of the body. • The animal can use this stored vitamin A during periods of feeding when the diet is deficient in carotene. • A horse can go for 3-6 months when Vit A is deficient, sheep 200 days.

18. Vitamin A Ration Considerations • May need to supplement when: • Poor quality or low levels of forage are available. • Limited amounts of colostrum . • Fed primarily corn silage and low carotene concentrates. • Grazing during drought, rations of cereal grains.

19. Vitamin A Ration Considerations • Vitamin A, in a stabilized form that is resistant to oxidation may be added to the ration through vitamin premixes. • Intramuscular injections of vitamin A may be used. • Stress conditions such as low temperature or exposure to infectious bacteria will increase the vit A requirements.

20. Excess Vit A in Diet • Feeding excessive amount of vit A to horse over along period of time may result in fragile bones, thickening of bony tissue, flaking off of the epithelium.

21. Vitamin D • Important for calcium absorption, Ca and P metabolism. • Fat soluble, stored in the body. • Less critical in mature versus younger animals. • Most important in animals in the third trimester of pregnancy.

22. Vitamin D Forms • Plant forms of vitamin D is ergocalciferol. • Animal forms of vitamin D is cholecalciferol. • The liver converts cholecalciferol to 25-hydroxy D3, which is the main form in which the vitamin circulates in the body.

23. Vitamin D Deficiency • Development of rickets, because of reduced Ca and P absorption. • Indicators are decreased appetite, slower growth, digestive disturbances, stiffness in gait, labored or fast breathing, irritability weakness and sometimes the development of tetany. • Symptoms develop more quickly in younger animals.

24. Vitamin D Deficiency • Pregnant animals may give virth to dead, weak or deformed young as a result of a vitamin D deficiency.

25. Vitamin D Sources • Diets that include sun-cured forages generally provide sufficient vitamin D. • Animals regularly exposed to sunlight or ultrviolet light also will not develop symptoms of vitamin D deficiency. • Green forages, barn cured hay and silages have some vitamin D. • Grains and grain by products have practically no vitamin D.

26. Vitamin D Sources • Vitamin D is more stable than vitamin A, does oxidize, has poor stability when mixed with minerals, especially calcium carbonate. • Rations with adequate levels of Ca and P will require less vitamin D.

27. Vitamin D Toxicity • Extremely toxic to poultry and horses. • Poultry can withstand 100 times the recommended amounts and horses 50 times. • Feeding massive doses in the last weeks of dairy cattle gestation has reduced milk fever.

28. Vitamin E • Functions as an antioxidant, which helps in the abosorption of storage of vitamin A • Vitamin E deficiency results in symptoms similar to selenium, whitemuscle, muscular dystrophy. • Whole cereal grains, green forages, good quality hay all have sufficient sources of Vitamin E.

29. Vitamin K • Necessary for the formation of prothrombin, (material that forms blood clots). • Deficiencies of vitamin K rarely occur because it is synthesized in the rumen. • Feeding moldy feeds may cause vitamin K deficiency leading to a bleeding syndrome. • Green leafy feeds, soybeans, fat soluble, solvent process soybean meal are good sources.

30. Vitamin C • Necessary for the formation of collagen. • Normally they synthesize sufficient amounts.

31. Feed Additives • Products used in animal nutrition that are not nutrients in the usual sense of the word. • Promote greater feed efficiency, produce more rapid gains or higher production. • Types of feed additives include antibiotics and antibacterials, hormones, anthelmintics and other miscellaneous compounds. • Majority are used when growing and/or finishing livestock.

32. Health Concerns • There has been a growing concern in recent ears that the use of some types of additives for livestock feeding may have an imact on human health as well as animal health. • Antibiotics and animal byproducts are the two most controversial issues today.

33. Water • Involved in many of the biochemical reactions in digestion and metabolism. • Transports nutrients and wastes. • Regulates body temperature. • Gives the body form by filling cells. • Provides lubrication. • Milk production.

34. Water • Animals can survive longer without feed than water. • Intake of water ranges from three toeight times the intake of dry matter. • All feeds contain water, 10% for air dry to more than 80% in fresh green forages. • Clean water should be readily available at all times.

35. Water • Temperature of water will effect intake. • Animals will drink more water if it is warmed slightly above freezing. • High humidity decreases water intake, while high ambient temperatures significantly increase water consumption. • Ph levels should be from 6-9.