INTRODUCTION

1. INTRODUCTION •  Feeds represent the most expensive input cost for the livestock producer • Expensive to maintain the animal • Expensive if don't supply nutrient in adequate amounts to get good performance • Expensive if overfeed nutrients relative to the animal's requirements

2. INTRODUCTION • Basic nutrients • Water • Protein • Energy: fat and carbohydrates • Minerals: macro and micro • Vitamins: fat soluble and water soluble

3. INTRODUCTION • Important to understand most limiting nutrient concept: • Animal performance • Environment • Balance • Cost

4. Feeds and ration formulation involves applications of the process of nutrient utilization: • Ingestion • prehension of feed, chewing and swallowing to the initial digestive organs •  Digestion • reduction of food to utilizable form; physical and chemical processing of ingested food • Absorption • food is reduced to utilizable form; transported from inside the digestive tract to the blood stream • active transport • passive diffusion • Metabolism

5. Biological Functions that Require Nutrients Maintenance: "the maintaining of an animal in a state of well being or good health from day to day". A maintenance ration is the feed required to adequately support an animal doing no non-vital work, making no growth, developing no fetus, storing no fat or yielding no product. As much as 100% of an animal’s ration

6. Maintenance • Energy for vital functions: heart, respiratory, membrane transport • energy expenditure gives off heat • Maintain body temperature • sources: heat from work of vital organs, heat from nutrient utilization, heat from work of normal activity, heat from economic work, heat from work of shivering

7. Maintenance • Protein for repair of tissue • there is constant breakdown or turnover of body tissue protein • excreted largely as urine • N excreted as urine during starvation equals maintenance requirement for protein • Minerals: some minerals excreted daily (not a problem) • Vitamins • Others: water, small amount of fats

8. Growth: increase in muscle, bone, and connective tissue (accumulation of fat is not growth) • Protein -- dry matter of muscle and connective tissue • Energy • Minerals -- especially calcium and phosphorus in young • Vitamins • Water -- free muscle tissue is about 75-80% water

9. Fattening • Deposition of unused energy in the form of fat • Internal fat (around abdominal organs), intermuscular, subcutaneous • Intramuscular fat • Fattening versus growth: growth is easier to deposit • muscle is mostly water • fat may actually replace water • 2.25 x's amount of energy in fat versus protein or carbohydrate • nature of the growth curve for all animals

10. Changes in body composition with increased age and weight of pigs age (days) weight (kg) 1 1-2 17 2-2 28 7 89 25 age (days) weight (kg) 144 60 183 90 200 110 water protein fat ash

11. Normal postnatal growth curves of bone, muscle, and fat.

12. Reproductive animals • Milk production: • nutrient requirements are in proportion to amount of milk produced • Major nutrients required are: energy, protein, Ca and P • Fetal development • ***fetal requirement for nutrients is not great • 83 lb calf (25% DM) = 22 lb of DM; which is only about 4 days of milk for the lactating animal • importance of nutrition during late gestation may be preparation for lactation (and rebreeding in cattle) • Others = wool, work, others

13. Nutrients from a Feed Management Perspective (Chapter 3, Kellems and Church) • Water • Water - most crucial nutrient -- most immediately required • 70% of lean body mass • Can only lose 10% of body water • Consume 3-4 times amount of water as dry matter (DM) • Consume an amount of water which is needed to maintain homeostasis (GIT, blood)

14. Water • Functions • transport (digesta, blood) • urine -- media to excrete nitrogenous waste • evaporative cooling • rumen microbes • Sources • drinking water • feed -- some feeds have up to 85% water • metabolic water -- oxidation of nutrients to produce water

15. Water • Practical Applications • water consumption is critical to maintain DM (nutrient) intake • requires management during hot and cold weather • requires management when high salt diets are fed

16. Energy Energy • Energy is very difficult to measure quantitatively • defined as calories -- amount of energy required to raise 1 g of water 1o C -- kilocalorie – megacalorie • Carbohydrate: C:H:O 1:2:1 C6H12O6 + 6 O26 CO2 + 6 H2O

17. Energy - Carbohydrates • Monosaccharides: • Glucose -- primary sugar • Fructose -- ketose, sweet, corn sweeteners • Galactose • Mannose • Arabinose • Xylose • Ribose

18. Energy – Carbohydrates - Polysaccharides •  Nonstructural carbohydrate (NSC) or non-fiber carbohydrate (NFC): mostly starch (some simple sugars), very extensively digested and/or fermented (90+ percent), not bulky • Amylose • Amylopectin: waxy grains, probably more extensively fermented ruminally • Glycogen; animal energy storage; liver and skeletal muscle

19. Amylose -1, 4 linkage CH2OH CH2OH CH2OH O O O O H H O H H H H H H H O O OH H OH H OH H O O HO OH H OH H OH H OH O O O O O O O O O

20. 6 6 CH2OH CH2OH O O 4 1 1 4 O O Structure of starch: Amylopectin, showing 1:6 branch point. 6 6 6 6 CH2OH CH2OH CH2 CH2OH O O O 4 1 1 1 4 4 4 1 O O O

21. Energy – Carbohydrates - Polysaccharides • Structural carbohydrate = fiber: less digestible even in the ruminant, very bulky - occupies much space in the GIT • cellulose: primary carbohydrate in fiber, comprised solely of β-1,4 linked glucose, lowly digestible • hemicellulose; secondary carbohydrate in fiber; made up of glucose, xylose, arabinose, mannose, galactose • lignin -- most significant anti-nutritional factor • amorphous polyphenols • gives support to the cell wall structure • present in the "woody" plant parts • increase as plant matures

22. Energy – Carbohydrates – Other Polymers • Pectin -- plant cell wall cement • Cutin - waxy coat of leaf surface

23. Cell Content Protein Sugar Fats Starch Pectins Primary Wall Secondary Wall Hemicellulose Cell Wall NDF Lignin ADF Cellulose Diagram of a plant cell showing cell wall structure

25. Energy – Structural Carbohydrates • Chemical treatment - objective is to make the SC fraction of forage more digestible • Ammoniation: anhydrous, aqua or urea • Untreated straw  42% digestible • Ammoniated straw  55% digestible • Effectiveness depends on conditions during treatment • Alkaline hydrogen peroxide; oxidizes the lignin

26. Ruminant system of carbohydrate digestion and absorption: Polysaccharide simple sugar absorbed 6 ME or Polysaccharide simple sugar fermented to VFA absorbed ME

27. Ruminant system of carbohydrate digestion and absorption:

28. Ruminant system of carbohydrate digestion and absorption: • Propionic acid most energy efficient VFA • Propionic acid increased by: • Feeding higher level of grain • Feeding ionophores • Ionophores (Rumensin and Bovatec): • Acetic acid,  propionic acid, no change in total VFA • Feed:gain • Methane production,  bloat

29. Ruminant system of carbohydrate digestion and absorption: Effect of feeding grain

30. Ruminant system of carbohydrate digestion and absorption: Effect of feeding grain

31. Energy – Lipids • fat = glycerol + fatty acids • triglyceride = glycerol + 3 fatty acids • fatty acid length -- C14 to C20 • very hydrogenated – energy • saturated vs unsaturated • essential fats • linoleic: C18-2 • linolenic: C18-3 • arachidonic: C20-4

32. Energy – Lipids • Feed applications • fats contain 2.25 x's energy per weight as CHO's -- CHO = 4 kcal/g; fat = 9 kcal/g • increase the energy density of a ration; must be limited, usually 5-6% of ration as lipid for ruminant, 6-7% for monogastric • reduce dustiness • may increase palatability • aid absorption of vitamin A,D,E,K • may decrease absorption of Ca, Mg, Na

33. Energy – Lipids • Feed applications – continue • fat will reduce fiber digestion in the rumen; commonly seen in the lactating dairy cow; restrict fat to about 6 percent of the total diet DM • now have ruminally inert fats on the market to avoid lower fiber digestion; best to have a combination of fat from basal ingredients, an oil source such as whole cottonseed or full fat canola, and inert fat • fat metabolism -- ketones -- ketosis

34. Protein • Most expensive nutrient per weight to supply • Functions • Muscle • Enzymes • Hormones • Antibiotics • skin, hair • Amino acids are what is actually required by the animal -- building blocks of protein

35. Protein • Protein  digestion  free AA  absorption  transported to the cell to synthesize a new protein for use by the animal • Animal can not absorb an intact protein • 21 naturally occurring AA • 10 essential AA

36. Protein • Dietary Essential AA -- an amino acid required by an animal and can not be synthesized by the animal in the amounts needed; and therefore must be present and available in the diet • Arginine • Histidine • Isoleucine • Leucine • Lysine • Methionine – S-containing, Cystine may provide ½ the reqmt • Phenylalanine -- tyrosine may provide ½ of the requirement • Threonine • Tryptophan • Valine • Nonessential AA -- required by the animal but can be produced in adequate amounts • Limiting AA -- AA that is first depleted during protein synthesis

37. Ruminant system of protein digestion and absorption • ** dietary AA are not the same AA that are absorbed and used to synthesize animal protein

39. Summary -- Advantages of the ruminant system º utilize fibrous feeds º utilize NPN º B vitamin production (plus vitamin K)

40. Minerals Macro mineral (Ca, P, K, Na, Cl, S, Mg) Micro mineral ( Fe, Co, Cu, F, I, Mn, Mo, Se, Zn, …) • sulfates more bio-available than oxides • chelated (or proteonated) minerals (Zn, Mn, Cu, Fe, Se) may be beneficial, but are much more expensive • Most recent is FDA approval of Se-methionine • Cu, Se, Zn and Fe are now recognized to be important factors in immune function Ca, P and Mg needed in greatest abundance and most commonly supplemented

41. Minerals • Antagonists-an element which inhibits the absorption or transport of another element

42. Minerals A.Sources Ca% P% 1.Oyster shell 38 2Ground limestone 36 3.Defluorinated rock phosphate 33 18 4.Dicalcium phosphate 23.4 18.7 5.Mono-ammonium phosphate 26.9 (12.2% N) 6.Mono-sodium phosphate 22.4 7.Forages .3-2 .15-.4 8.Grain <.05 .3-.4 9.Requirement .3 to .4 .25 Ca:P ratio = 1.2 to 1.5:1 for growing animals and dairy 6:1 laying hens

43. Minerals • Phytate phosphorus • Form of P bound in phytic acid, most P in grains is in phytate form • This form of P is lowly available for monogastrics but is available for ruminants • Interest in phytase to increase utilization of P in basal ingredients - both endogenous and exogenous phytase

44. Minerals • Magnesium -- hypomagnesemia -- grass tetany • during cool season, low root uptake of Mg • or if dietary Ca is too high • or when high soil (forage) K • or low soil P • desire K:(Mg + Ca) < 2.3 in grazed forage • supplement with MgO, MgSO4, legumes • Symptoms include muscular twitching, collapse, convulsion

45. Trace minerals

46. Selenium • Selenium -- Se deficient soils • FDA will now allow supplemental Se at .3 ppm; seems to be level we need for of Se-deficient soils

47. Copper • Copper - - deficiency of grazing animals throughout the western states; probably more associated with Mo antagonism • Want a Cu:Mo ratio in vegetation greater than 7

48. Thiomolybdates Mo, S (as sulfate, sulfide or S amino acids), Cu and Fe all enter the rumen via feed, soil, water or supplements. Reactions occur between Mo and S enabling the formation of thiomolybdate compounds which will readily bind Cu. In the absence of rumen-available Cu (rumen-labile Cu), thiomolybdates are able to be absorbed through the rumen wall and small intestine, allowing them to bind to Cu-containing substances, including enzymes whose activity will be reduced, thus causing clinical problems often quoted as Cu deficiency, even though it is strictly a thiomolybdate toxicity. Gould and Kendall, 2011

49. Copper Toxicosis • Sheep particularly sensitive to copper • 5 ppm Cu • Excessive Cu builds up in RBC, causing Heinz-body formation and methemoglobin production • Can’t bind oxygen-chocolate blood • Release of hemoglobin damages kidneys • Avoid feeding cattle mineral

50. Vitamin premixes • Fat (A, D, E, K) vs. water soluble (B vitamins, C) • Vitamin Premixes (0.5-1.0% of diet) • Complete vitamin packages-may contain synthetic antioxidants to increase stability • Loss of vitamins in feedstuffs • Heat/humidity increase oxidation of A, E, thiamin, riboflavin and biotin • Vitamin/mineral premixes less stable