EDAG 2103 Animal Production Nutrition Notes.pptx

This comprehensive course covers the principles and practices of animal production and nutrition, including the biology of animal growth and development, nutrient requirements, feeding systems, and nutritional management. Students will learn to calculate nutrient requirements for different animal species and production systems, evaluate feed quality and formulate balanced diets, and apply nutritional management strategies to optimize animal productivity. The course also covers the economic and environmental aspects of animal production, providing a holistic understanding of the field. By the end of the course, students will have a deep understanding of the complex relationships between animal nutrition, growth, and productivity, and be equipped to make informed decisions in animal production systems. The course is suitable for students, researchers, and professionals in animal science, veterinary medicine, and related fields, and assumes a basic knowledge of biology, chemistry, and mathematics.

1. ANIMAL PRODUCTION AND NUTRITION LECTURE NOTES ( EDAG 2103) A. Mugoti LUPANE STATE UNIVERSITY [email protected] Cell: [phone]

2. Outline of course content SECTION I : THE ANIMAL AND ITS FOOD ( i ) Classification and Chemical value of animal feeds Dry Forage and roughages, pastures, range plants, silages. Energy contributing feeds, protein supplements, mineral and vitamin supplements, feed additives. (ii) Chemical Composition of feeds Biochemistry of feed constituents: Water, dry matter, organic constituents, inorganic constituents. (iii) Analysis of feeds Proximate analysis scheme, Van Soest and Moore Systems

3. Outline of course… SECTION II: BIOCHEMISTRY OF DIGESTION AND ABSORPTION OF NUTRIENTS Carbohydrates, lipids, proteins, inorganic components in monogastrics and ruminants. Effect of anti-nutritional factors. Principles of rumen and post rumen fermentation, and protein degradation .

4. Outline of course… SECTION III: DIGESTIBILITY OF FEEDSTUFFS ( i ) Measurement of dry matter, organic matter, NDF digestibilities in vivo , in-vitro (Tilley and Terry), gas production technique and using enzymatic methods. (ii) Validity and limitations of digestibility coefficients, (iii) Factors affecting digestibility, (iv)Indicator method, Nylon bag method, mobile nylon bag technique, (v) Feeding trials, Balance trials.

5. Outline of course… Section IV: Antinutritional Factors Section V: Trends in Climate Change and Animal Nutrition END OF COURSE

6. SECTION 1

7. SECTION I:THE ANIMAL AND ITS FOOD Classification and Chemical value of animal feeds Dry forage and roughages, pastures, range plants, silages. Energy contributing feeds, protein supplements, mineral and vitamin supplements, feed additives. Chemical Composition of feeds Biochemistry of feed constituents: Water, dry matter, organic constituents, inorganic constituents. Analysis of feeds Proximate analysis scheme, Van Soest and Moore Systems

8. Classification and Chemical value of animal feeds Define a feed/ feedstuff/ nutrient? Anything edible that after ingestion can be absorbed and utilised by the animal. Nutrients are those components of the feed that are absorbed by the animal’s GIT. Feed consists of water and Dry Matter (DM). If the water content in feed is 75%, the DM content is 25%. Various classification systems are employed to differentiate feedstuffs, each according to a certain purpose. McDonald et al . (2011) (Animal Nutrition 7 th ed., Part 5) Two systems: an international system of classifying feeds so that we can communicate. the Central African region system

9. Classification of animal feeds.... i ) International classification system feeds are classified into eight (8) classes. Class 1: Forage or roughages . This comprises of very fibrous feed, which contain more than 18 %CF. In this class we find all forms of hay, both legume and non-legume hays. Crop residues like maize, wheat, barley stovers , sunflower and groundnut hulls and shells. Class 2: Succulents. This group includes the green plants or pasture. These could be cut and feed green to animals. They have characteristically high moisture content of greater than 65 %. Class 3: Silages. These are feed material produced by controlled fermentation of a crop of high moisture content. These materials could be legume or non-legume or a mixture of both. Class 4: Energy feeds. Have less than 18 % CP content. In this class we find most of the grain cereals and their by-products. Class 5: Oil seeds and grain legumes - the feeds have a CP content of equal to or greater than 20 %.

10. C lassification of Animal Feeds Class 6: Mineral supplements. They are sources of minerals to the animals. The best example is monocalcium phosphate. This will be used to supply both calcium and phosphorus. Can you think of vitamin supplements? Class 7: Vitamin supplements. These will only be fed to animals specifically to supply the vitamins. Class 8: Feed additives. Feed additives are ingredients or substances or chemicals added to a basic feed mix, usually in small quantities for the purpose of fortifying the basic mix with certain nutrients, stimulants and or medicines. The use of feed additives is controversial. In some countries, they have been banned completely, whilst in other they are still being used. In Zimbabwe some of these are available and registered for use.

11. Classification of animal feeds.... ii) Central Africa classification system Feed classified into four (4) categories namely grasslands/veld and forages; cereals and cereal by-products; oilseeds and grain legumes; animal by products. Grasslands/veld and forages Natural grasslands /veld and cultivated pastures play a significant role in feeding livestock in Central and Southern Africa, especially the ruminants. The grasses have different palatability and growth patterns but have similar composition and feeding value. Generally the pastures have higher nutritive value in terms of protein and phosphorus. The nutritive value of grasses declines with stage of growth. Young actively growing grasses contain 12 to 16 % CP on dry matter basis. At maturity the same plants have as low as 1 to 3 % CP

12. ii) Central Africa classification system... Grasslands/veld and forages nutritive value depends on leaf to stem ratio and declines rapidly after flowering. energy content of the grasses declines in the same way as the CP content. The crude fibre content increases with maturity of the grasses. lignin and P content will increase and decline, respectively as the plant matures. actively growing grasses contain high levels of carotene, which animals convert to vitamin A. Are also rich in B complex vitamins and vitamin E. The vitamin content will decline with maturity. If range cattle are fed on matured or dead grasses they will lose their body condition.

13. Grasslands/veld and forages... Differences between temperate (C3) and tropical (C4) ranges Developing countries, mostly located in the tropical areas (within the tropics) of the world, animals are often managed in small numbers, utilising the by products of agriculture, agro-industries or grazing pasture on land not easily farmed or too infertile for cropping. The cost of agricultural labour in these countries is relatively low or is not an issue such as the cost of family labour. land for ruminant feed such as pasture or crops specifically grown for forage is not generally available and the animal must depend on locally available by-products of agriculture and industry which are often deficient in certain nutrients. There is a need to optimise production from the available resources by providing minimum amounts of the deficient nutrients. The level of production is even then often well below the animal’s genetic potential. Developed (temperate) countries, in order to be profitable animal productivity needs to be maximised by meeting the animals' requirements for nutrients. To achieve these farmers generally use high quality energy dense feeds which are also high in protein. The nutritional research required in the temperate countries therefore is largely fine tuning of the nutrient balances arising for digestion and absorption from a diet.

14. ii) Central Africa classification system... Cereal grains & cereal by-products members of the gramineae which are cultivated for their seed are essentially CHO concentrates, main component being starch concentrated in endosperm proteins are highly concentrated in the embryo and aleurone layer of the seed protein is deficient in certain indispensable aa lysine and methionine lipid content varies with species

15. ii) Central Africa classification system... Maize Diff types of Zea mays, grain colour red, white or yellow Yellow maize contains pigment cryptoxanth , a precursor for Vit A Yellow pigmentation desirable for laying hens, contributes to prodn of yellow colouration of egg yolk Maize by-products: germ, bran & gluten Germ-rich in oil for human consumption Bran ( pericap & testa ) - , high in CF, normally fed to animals in tropical regions Gluten- high in CP ( upto 700g/kg) & is high in pigments essential for poultry diets The 3 products are usually mixed together and sold as maize gluten feed..where ? Wheat, rice, millet, sorghum

16. ii) Central Africa classification system... Oilseeds and grain legumes Oil seed cakes & meals are residues remaining after removal of oil from the seeds. Residues are rich in protein & are therefore valuable feeds for livestock Are of tropical origin & include groundnut, cotton seed, soyabean and sunflower meals/cakes Oil normally removed by: Applying pressure to force out the oil Use of organic solvents (hexane) to dissolve oil from the seed (solvent extraction of seeds with an oil content of less than 350g/kg )

17. Oilseeds and grain legumes cntd Decortication-removal of thick coat or husk by cracking or riddling the seeds of groundnuts , cotton seed & sunflower Husk rich in fibre, low digestibility, lowers nutritive value Protein quality of a particular oilseed is relatively constant but that of the meal or cake derived from it varies with method of oil extraction Digestive disturbances from uncontrolled se of oil-rich cakes, esp unsaturated oil lowers carcass quality, cause soft milk & body fat

18. ii) Central Africa classification system... Animal by products are usually given to animals in smaller amounts to make good deficiencies of certain indispensible amino acids from monogastrics on an all-vegetable-protein diet also importantly, contribute to animal mineral nutrition & supply vitamins of the B-complex very expensive, their large scale use is uneconomic Examples: Meat and bone-meal, milk, fish meal and poultry manure

19. Chemical Composition of feeds

20. Chemical Comp of feeds…

21. Nutrient Comp of animal body

22. Nutrients for different classes Feed group Key nutrients Grass and forage crops Energy, protein, fibre, vitamins, minerals & trace elements Dried forages and straw Fibre, minerals & trace elements Silages Energy, protein, fibre, minerals & trace elements Roots tubers, Cereals & related by-products Energy, minerals & trace elements Protein concentrates Protein, energy, minerals & trace elements Vitamins and trace minerals Vitamins, minerals & trace elements

23. Analysis of feed Analysis of feeds can be done using: Physical procedures; Chemical analysis Proximate analysis, Detergent fibre system ; Biological systems; feeding/ metabolism trials; in vivo , in situ / sacco , in vitro methods

24. Feed evaluation methods a) Physical analysis of feeds For you to produce or buy superior feeds you need to know what makes feed quality and how to recognise it. You need to be familiar with those recognisable characteristics of feeds, which indicate high palatability and nutrient content. The best way though, may be to observe the animals feeding. Animals prefer and thrive on high quality feed. Physical evaluation of feedstuffs is based on the eye and smell appeal. For hays it must show that it was cut whilst young. It must be leafy and bright green indicating proper curing. It must be free of weeds and stubble. There must be no moulds or dust soil. The hay must have pleasing fragrant smell. For silage you should have a pleasing acid smell. The taste should not be bitter or sharp. The silage should be free of moulds or slims. A green or brown silage is good. For the grains and other concentrate, the seeds should not be crashed or split. They should have a good colour peculiar to that species, again no moulds, rodent or insect damage or foreign materials. You should be able to pick a castor bean seed in soyabean seed, as this can be disastrous if left in the seeds. The concentrates and seeds should be free from rancid odour. Other people examine their feeds under the microscope checking for foreign objects such as iron filings, rodent excreta, and moulds.

25. b) Chemical Analysis of feeds Today , many agricultural experiments stations and large feed companies have facilities to analyse feeds by complicated chemical procedures. These analyses are done to prevent and detect any nutritional problems. Feed composition tables are also generated from these chemical analyses. The tables are used as the basis for ration formulation and for feed buying and merchandising. The law also requires that the commercially prepared feeds be labelled with a list of guaranteed analysis. The laws require that the feed label (tag) show in percent the minimum crude protein and fat; and maximum crude fibre and ash.

26. i ) Proximate analysis Devised by Henneberg and Stohmann a 100 years ago this system estimates the potential value of a feed or feedstuff for feeding purposes without using animals. it is based on the separation of feed components into fractions or groups in relation to their feeding values. it divides the feed into six fractions: moisture, ash, CP, EE, CF and NFE. Resources : McDonald et al . (2011) (Animal Nutrition 7 th ed., Part 1, Chp 1); http://www.fao.org/docrep/field/003/ab479e/ab479e03.htm

27. Water / moisture Water is vital to any animal. The bodies of young animals may consist up to 80% of their live weight. Older, and especially fat animals, have less water in their bodies (down to 50%). Feeds can contain both high and low water percentages. Examples of feeds with high water contents are young grass (± 15% DM) and cabbage (< 10% DM). Hay and concentrates are feeds with low water contents (85-90% DM). An animal obtains water from three sources: drinking water , water present in food and metabolic water . Water or moisture content should be determined first in order to compare the feeding value of feed. Those with high moisture content tend to reduce the dry matter intake. As a result of this variation in water content of many feeds, statements of the feeding value of feeds are being reported in moisture free (dry matter) basis. The feed sample whose water has been removed in referred to as dry matter. The water content can be determined by heating the sample at 100˚C to a constant weight in an oven over 24 hrs or 70˚C for 36 hrs or by vacuum drying or distillation with a chemical called toluene or by freeze drying or using moisture meters based on the conductivity. The heating system is what is used commonly here in Zimbabwe.

28. Water/ moisture…. Calculating moisture content two methods; Method A loss of mass during heating x 100 = % water Mass of sample before drying   Method B: Mass of sample after drying x 100 = %DM (Dry matter) Mass of sample before drying   100 - % DM = % water

29. What are the functions of water in animal nutrition? ?????????????????????????????????

30. Dry matter Although water is very important, the DM is crucial to the composition of a ration. Why? All valuable feed substances i.e nutrients are contained in the DM. If the DM% in a feed is known, it is possible to calculate how many kg DM an animal obtains from the feedstuff (and how many kg concentrate is needed as a supplement according to the norms for the production level). DM consist of: ash, Crude Protein (CP), Ether Extract (EE), Crude Fibre (CF) and Nitrogen Free Extract (NFE).

31. Dry matter … Ash the ash fraction of the proximate analysis stands for the inorganic compounds found in the feed. the weighed sample in porcelain crucible is ignited in a muffle furnace at more than 600˚C. the residue that is left after burning is termed ash. The process has removed the water, fat, protein and carbohydrates. this is a high temperature treatment that may alter forms of some minerals and may volatilise some minerals like chlorine, zinc, selenium and iodine. the percentage ash content is calculated as: Mass of sample after burning x 100 = % ash or mineral matter Mass of original sample

32. Dry matter… Crude Protein (CP) Protein on average is taken to contain 16 % N. It is therefore possible to estimate the amount of protein a feed contains, if we know the N content. multiply the amount of N by the factor of 6.25 [100/16]. the method used to determine the nitrogen content of feeds is called the K jeldahl process. small dried sample is digested in concentrated sulphuric acid until all the organic matter is destroyed. N from the feed is converted into ammonium sulphate. the digested material is then neutralized with sodium hydroxide, distilled driving the ammonia over the standard acid and titrated. this will determine the amount of nitrogen in the sample

33. Crude Protein (CP)... E.g Given that a feed has 2 % nitrogen then its CP content is: 2/100 x 6.25 = 12.50 % CP. the analysis does not tell if the feed mixture has true protein or other forms of nitrogen (NPN). the procedure does not convert Nitrate N to ammonium salts.

34. Dry matter… Ether extract (EE) the feed sample is boiled in a special designed apparatus in ether. ether will dissolve the fat fraction. after this the ether is evaporated. the loss in weight makes up the ether extract. the % EE is calculated as follows: Mass of the ether extract x 100 = % ether extract Mass of sample used this procedure will include any ether soluble fat compounds including some non-nutrient compounds like chlorophyll, volatile oils, resins, pigments and plant waxes which are of little value to animals.

35. Dry matter… Crude fibre (CF) is an indicator of the ease with which digestion of the feed occurs, and bulkiness of the feed. contains those materials like cellulose, hemicelluloses and some lignin if present. feed sample is boiled in dilute acid, then dilute alkali. This imitates the digestion action of digestion enzymes. residue is weighed and ashed . The difference between the initial residue mass and the ashed mass gives the mass of fibre present in the sample. After removal of water and ether extract from a feed, the sample is boiled in weak acid (0.255N H 2 SO 4 ), then in weak alkali (0.312N NaOH ). This removes the proteins, sugars, and starches. Cellulose, lignin and mineral matter will be the residue. This material is then dried and weighed and then burnt in a muffle furnace at 600 C. The loss in weight is recorded as the crude fibre.   Mass of sample after boiling – Mass of sample after ashing x 100 = % CF Mass of original sample

36. Dry matter… Nitrogen-free extract (NFE) this fraction is meant to represent the carbohydrate content of feed. this fraction is determined by difference. all the fractions we discussed above are added together and subtracted from 100 as follows: Nitrogen-free-extract (NFE) =100 - (%moisture + %CF + %ash + %EE + %CP) this may also contain organic acids and water-soluble vitamins in addition to readily available carbohydrates

37. i ) Proximate analysis.. Pros and cons one of the advantages is that most laboratories are equipped to run this type of analysis, no need for dear and complicated equipment. PA provides a good general evaluation of the feed a feed high in CF will be inferior in feeding value to one that is very low in CF. the TDN system of feeding standards is based on the proximate analysis. although considered old, this system is still in use today in Zimbabwe and that most of the data available on feed composition to date is reported in terms of proximate analysis fractions. major disadvantage -the system does not define the individual nutrients of the feed. Instead, the fractions are mixtures of the various nutrients. the PA is not accurate.

38. i ) Proximate analysis.. Cons Assumptions and adjustments are used in the calculations of several components. CP is calculated based on the assumption that proteins contain 16 %N. In, real terms, some feeds contain protein with more that 16 %N, other protein contain less N (milk?). This calculation assumes that all the N in the feed is in the form of proteins. The other compounds like amines, amides and nitrate are in feed although their levels could be low. Most criticism of the proximate analysis procedure has been on the CF, ash and NFE fractions. The CF is also a rough estimate of indigestible portion of the feedstuff. The cellulose and hemi-cellulose while similar in nutritive value have greater feeding value for ruminants than in non-ruminants. Alternative procedures for fibre have been developed by Van Soest. The proximate analysis involves time consuming stages. These stages cannot be done by automatic machines. It does not tell us how much indigestible material there is in a feed. The acid-alkali boiling dissolves some compounds of feed that no animal can digest, and like other chemical analysis it does not tell us the palatability, texture, toxicity or nutritional availability. It underestimates and overestimates others fractions

39. ii) Van Soest or Detergent System of fibre analysis procedure divides the feed DM into highly digested and the other lowly digested portions. this is achieved by boiling the feed sample in a neutral detergent solution then filtering. the portion that is dissolved in the solution consists of cell contents. These include lipids, sugars, starches and proteins. these are known as neutral detergent solubles (NDS). These are easily digested. the insoluble portion is composed of plant cell wall and includes cellulose, lignin, silica, hemicellulose, (and some bound and damaged proteins). They are referred to as the neutral detergent fibre (NDF). the fibre content determined by the detergent system is higher than the crude fibre determined by the proximate analysis. this is because in the neutral detergent system essentially all the lignin and hemicelluloses are included in the NDF whilst in the CF of the proximate analysis some amounts of the two compounds are lost to the NFE.

40. Table 1.2 Classification of forage fractions using the detergent methods of Van Soest.

41. Relationship of two systems of dividing forage organic matter

42. Van Soest... The NDF is further divided by boiling in an acid detergent solution. Hemicellulose is dissolved leaving the lignin and the soil silica and cellulose. The cellulose is then separated by the addition of sulphuric acid. This leaves lignin and the silica and they constitute the acid detergent fibre (ADF). This last residue is put in a furnace to burn it. The difference before and after burning gives the amount of lignin present in the feed or the acid detergent lignin (ADL). The modified acid detergent fibre (MADF) is a change of the ADF system where the strength of the acid has been increased and the duration of boiling increased.  The other methods used include the chromatography, colorimetry and spectrophotometry . These are beyond our scope though they are important.

43. Modern methods of analysing feed W et chemical analysis of feed samples is time consuming and expensive PA criticised by animal nutritionists as archaic and imprecise CF, ash, NFE Minerals Spectroscopy are used for the analysis of many minerals, vitamins, blood constituents, and other biologically important compounds Spectrophotometry - the measurement of the light transmitting power of a solution to determine the concentration of light absorbing material present in thesolution . 2 units of measurement in : transmittance and absorbance or optical density (most common unit)

44. Modern methods of analysing feed.. Minerals... Spectroscopy: 2 major approaches; Directly measure the light absorbed by an ion or molecule itself Add a reagent to the compound to produce a complex that will readily absorb light on measurement (applied to many analyses commonly performed in nutrition laboratories e.g., P, glucose) Basic components of a absorption/atomic spectrophotometer

45. Modern methods of analysing feed.. Atomic absorption Spectroscopy measurement of the absorption of light by free atoms an atomic absorption spectrophotometer is an instrument that uses this principle to analyze the concentration of metals in solution. the substances in a solution are suctioned into an excited phase where they undergo vaporization, & are broken down into small fragmented atoms by discharge, flame or plasma by exposing these atoms to such temperatures they are able to “jump” to high energy levels & in return, emit light

46. Modern methods of analysing feed.. Flame emission spectroscopy Involves measurement of the intensity of radiation of an excited atom at a given spectral line qualitative analysis of metallic element concentrationsis done using FES in the same manner in which it is done using AES the spectrum of the analyte is obtained and compared with the atomic and ionic spectra of possible elements in the analyte . Nuclear magnetic resonance spectroscopy Is based on the approach that some atomic nuclei which can be identified from a nuclear magnetic resonance spectrum, measures variations in frequency of magnetic radiation absorbed in smaple . Provides more specific & detailed information on conformational structure of compounds More expensive, requires more time and skills for the operator

47. Modern methods of analysing feed.. Inductively coupled plasma emission spectroscopy (ICP-ES) use of electrically generated plasmas, rather than fuel-fired flames to produce atomic emission. A plasma is a gas in which a significant number of the atoms or molecules are ionized. Because it is an electrical conductor, it can be heated rapidly by inductively coupling it to a time-varying magnetic field

48. Modern methods of analysing feed... Near infra red spectroscopy (NIRS) a rapid, non-destructive and reliable prediction of the chemical composition (structural fibre, soluble carbohydrate, crude protein, lipid and ash.) of feed (fresh or dried), animal products, soils etc NIRS can also predict the digestibility and metabolisable energy(ME) value of a feed Method: a sample ( e.g 0.5–1.0 g ash) is exposed to an electro-magnetic scan over a spectral wavelength range of 1100 to 2500 nm (near infrared) Remember a nanometer is 1 millionth of a meter the energy in this spectral range is directed on to the sample & is absorbed by H-containing functional groups in organic compounds in a sample, (C-H, O-H, N-H, S-H) i.e the bonds are subject to vibrational energy changes when irradiated by NIR frequencies

49. the energy (R) reflected in the absorption spectrum is measured by the instrument, the NIR spectrometer Absorption bands due to water (1450 nm) and protein functional groups (2100 to 2200 nm) are identified method requires minimal sample preparation, with high accuracy NIRS has been accepted as an official Association of Official Agricultural Chemists (AOAC) method for CP , ADF and moisture

50. 1- light source, 2-beam splitter system, 3-reflector, 4-sample chamber/detector inlet valve, 5-diffuse reflection detector, 6-transmission detector, 7-control and data processing analyzed system, 8-printer.

51. Modern methods of analysing feed...

52. Modern methods of analysing feed... Calibrations; are based on the statistical analysis of the relationship between mathematically transformed spectra and the frequency of chemical bonds in an organic matrix various statistical models are used e.g , Principal Component Regression & Multiple Linear Regression each statistical model allows exploration of relationships of reflectance/absorption values of diverse sets of chemical bonds in the dried/wet sample and wet chemistry values of samples. Calibration procedures are time consuming & only worthwhile for subsequent analysis of large sample numbers High instrument costs.

53. Modern methods of analysing feed... Amino acids, fatty acids and sugars High-performance liquid chromatography Ion exchange chromatography Reverse phase chromatography

54. End of section 1

55. SECTION 2

56. Section II: Biochemistry of digestion and absorption of nutrients Physiology of the digestive system see AS103 notes Anatomy recap....importance in feed evaluation.. Pig Chicken

57. Biochemistry of digestion and absorption of nutrients Cattle Horse

58. Digestive Process - Monogastrics Proteins Fats Starch MOUTH STOMACH SMALL INTESTINE Peptides proteases Amino acids peptidases Fatty acids bile salts lipases Maltose amylase Glucose amylase maltase = main site of absorption

59. Biochemistry of digestion and absorption of nutrients..

60. Biochemistry of digestion and absorption of nutrients..

61. CHOs digestion and absorption Are classified based on No. of sugar units & C atoms per sugar unit CHOs make up 75% of DM of many plants on which many animals primarily depend on; make up 70-80% of swine & poultry diets (major source of energy) fermentation of fibers (largely hemicellulose) , limited in pigs & poultry Lipids and protein contribute some energy, but starch & sugars are 1’ CHO availability is affected by digestibility, absorption of end products of digestion, and metabolism of absorbed products. Digestibility is the most important factor in efficiency of feed utilization, & it’s an inherent feature of feedstuffs to a large extent. Sites of CHO digestion

62. CHOs digestion & absorption... Salivary digestion : Fowl lack amylase in saliva, Pigs have “ptyalin “- a weak α -amylase in saliva, which is similar to pancreatic amylase breakdown starch to a mixture of maltose, maltotriose & various dextrins GIT digestion The process of absorption of sugars at the SI mucosa is similar for a wide range of species although small amounts of disaccharides may be absorbed from gut lumen, a bulk of dietary CHOs is absorbed as monosaccharides Simple diffusion or active transport Important to have “OH” on C 2 (the same configuration as glucose) and a pyranose ring

63. CHOs digestion and absorption… In lumen Starch 🡪 maltose + maltriose + α-limit dextrins Amylase At brush-border Maltose/maltriose 🡪 glucose Glucoamylase (maltase) Sucrase-isomaltase α-limit dextrins 🡪 glucose Sucrase-isomaltase Sucrose 🡪 glucose + fructose Sucrase-isomaltase Lactose 🡪 glucose + galactose Lactase SGLT-1 Na + coupled (Na/K ATPase for gradient) D- hexoses w/ pyranose ring apical basolateral GLUT-5 Fructose absorption Jejunum Facilitated diffusion GLUT-2

64. CHOs digestion & absorption...

65. Protein digestion & absorption Classification of Protein A. Simple proteins - Refer to a protein that yields only AA and(or) its derivatives upon hydrolysis. B. Conjugated proteins: (e.g.) Nucleoproteins - e.g., Ribosomes/RNA. Phosphoproteins - e.g., Casein/phosphate. Metalloproteins - e.g., Cytochrome oxidase/Fe & Cu. Lipoproteins - e.g., VLDL/phospholipid, fat, cholesterol. Flavoproteins - e.g., succinic dehydrogenase/FAD. Glycoproteins - e.g., γ-globulin/galactose, mannose, hexoamine C. Fibrous or globular proteins: Fibrous proteins - Polypeptide chains are coiled into a helix & cross-linked by disulfide & H-bonds: Collagen (in connective tissues) - Heating or treating with acid, yields gelatin . Elastin (part of tendons, arteries & others) - Can stretch in two directions (poorly digested by animals). Keratin - α-keratin is found in hair, horn and wool, whereas β-keratin is found in beaks of birds. Myosin & tropomyosin - Muscle protein

66. Protein digestion & absorption... C. Fibrous or globular proteins:.. Globular proteins Polypeptides are folded & coiled - very compact proteins! Examples include enzymes, protein hormones & oxygen carrying protein D. Classifications by solubility: Albumins - Soluble in water and salt solutions. Globulins - Insoluble in water, but can increase solubility by changing salt concentrations. (Many plant seeds contain globulins!) Protamine - Soluble in a 70-80% ethanol, but insoluble in water & ethanol. Histone - Soluble in salt solutions. Scleroprotein - Insoluble in water or salt solutions.

67. Protein digestion & absorption... Gastric Digestion HCl & pepsin: Are primarily responsible for gastric digestion. Histamine, which is released in response to vagus nerve stimulation & gastrin, stimulates secretion of both. Secretin inhibits acid secretion, but stimulates pepsin secretion. GIP (gastric inhibitory polypeptide) inhibits pepsin secretion Pepsin cuts protein into peptides in the stomach Intestinal Digestion Primary site is the duodenum, where feed is mixed with pancreatic & duodenal secretions. pH of ingesta increase progressively, and reaches app 7 by the time ingesta get to the end of ileum, thus digestion by pancreatic enzymes rather than pepsin. Intestinal digestion consists of two phases: the intraluminal, and membrane & intracellular digestion. Proteolytic enzymes involved: Endopeptidases – act on a susceptible peptides link in polypeptide/protein. Carboypeptodase – remove AA residues from the carboxyl end of the chain. Aminopeptidases – remove AA residues from the amino end of the chain.

68. Protein digestion & absorption... In lumen Protein 🡪 AA, di- & tripeptides, & (AA) n via pancreatic PROTEASES Endopeptidases (chymotrypsin, elastin, trypsin) cut proteins and larger peptides into smaller peptides Exopeptidases (carboxypeptidases) Secreted as zymogens by pancreas Activated by TRYPSIN Trypsinogen 🡪 trypsin via ENTEROPEPTIDASE (brush border) At brush-border Oligopeptides 🡪 AA, di- & tripeptides via aminopeptidase and carboxypeptidases A and B Also cytoplasmic peptidases Apical AA transporter Na + coupled PepT1 H + / oligo peptide Basolateral AA transporter Na + independent

69. Protein digestion & absorption... Absorption of amino acids and peptides most amino acids are absorbed by the active process involving Na & membrane carriers (probably, protein) Mechanisms of absorption can be classified into four distinct amino acid transport systems? Neutral system: Transports monoamino & monocarboxylic amino acids (Ala, Asn , Cys , Gln , His, Ile, Leu , Met, Phe , Ser , Thr , Trp , Tyr, Val). Active process (Na+-dependent) & very rapid. Amino acids compete with each other for absorption. Basic system: Transports diamino acids ( Arg , Lys, Orn & cystine ). Active (Na+-dependent) & fairly rapid (but the rate is only about 10% of the neutral system).

70. Protein digestion & absorption..... Mechanisms of absorption... Acid system: Transports dicarboxylic amino acids (Asp & Glu ). Partially Na+-dependent, and probably active. AAsp & Glu - both are rapidly removed by transamination process at the intestine after uptake,  difficult to determine whether they are transported against concentration gradient! Imino acid & glycine system: Transports two imino acids, Pro & Hyp (+ Gly ). May not require Na+, and the rate is slower than three other systems. There may be some interactions among these systems - e.g., some neutral AA use carrier(s) for basic AA, and neutral AA may stimulate transport of basic AA

71. Absorption of peptides cntd Only app 1/3 of total amino acids may exist as free-AA in the intestinal lumen, thus, there must be some peptide absorption Little effect on absorption of free-amino acids, i.e., independent mechanisms for AA & peptides. As in AA absorption, there are competitions among peptides for absorption

72. Protein digestion & absorption..... Absorption of peptides Dipeptides and tripeptides are absorbed faster than free aa at the intestinal epithelium. Based on the evaluation with tetraglycine , there has been no evidence of intact absorption of tetrapeptides (Probably, hydrolyzed to tri- & dipeptides before uptake/absorption ) But conclusions are based on tetraglycine , which is, perhaps, the simplest form of tetrapeptide

73. Lipid digestion & absorption Classification of Lipids A. Based on the No. of C atoms and the degree of unsaturation: Saturated fatty acid (SFA) - No double bonds. Unsaturated fatty acid (UFA) - One or more double bonds. Polyunsaturated fatty acids - Two or more double bonds. B. Natural lipids (plant & animal origin): Made up of triglycerides (glycerol + 3 FA). Most FA have 8 to 24 C with 16 to 18 C being common for many feed lipids. In generals, plant sources are highly unsaturated, whereas most animal sources are 50:50. The ratio of saturated to unsaturated or vice versa has some implications on the efficiency of lipid utilization! Short (< 10 C) or medium chain FA - FA with 14 C or less Most commonly used lipids/lipid sources contain a lot of 16 to 18 C f.a . http://lipidlibrary.aocs.org/Lipids/tag2/index.htm

74. Physical and Chemical Characteristics of Lipids

75. Lipid digestion & absorption… The major dietary lipids for animals are triglycerides or neutral fats in foods of animal or plant origin. A small amount of ingested fat is digested in the stomach by a fat-splitting enzyme, gastric lipase. Most fat digestion occurs in the small intestine. A coarse emulsion enters the duodenum from the stomach or gizzard. Bile salts interact with fat droplets to form emulsion droplets, and along with lipase & colipase, reduce lipids to finer/small size emulsions. Lipase and colipase: hydrolyze TG droplets into FA and monoglycerides . preferentially remove FA in 1 & 3 positions, leaving 2-monoglycerides. colipase & bile salt both needed for the lipase activity becoz : without colipase or bile, lipase is absorbed & denatured at the interface. with bile salt but no colipase, lipase remains in the aqueous phase. Colipase is required for the attachment/function of lipase at the substrate-water interface Bile is stored in the gallbladder and drawn upon as needed. Bile salts are amphipathic compounds that act as biological detergents, converting dietary fats into mixed micelles of bile salts and triacylglycerols . Micelle formation increases the fraction of lipid molecules accessible to the action of water-soluble lipases in the intestines

76. Lipid digestion & absorption..

77. Lipid digestion & absorption.. Mechanism of lipid digestion in small intestines

78. Lipid digestion & absorption.. Formation of micelles: Consist of 2-monoglycerides, FFA & bile salts. Outside, polar (hydrophilic) & center , non-polar (lipophilic). The rate of formation is a critical step in fat digestion/absorption! Migration of micelles to the brush border (lower duodenum): Micelles are disrupted. FA & monoglycerides are absorbed. Bile salts - Reused/eventually absorbed at the lower tract & recirculated via the liver. Absorbed monoglycerides and FA are resynthesized into TG & phospholipids. TG are combined with cholesterol & phospholipids to form chylomicron (pig) or very low density lipoprotein (fowl) Digestion and absorption of trigylcerides

79. Fat digestion and absorption EMULSION DROPLET 🡪 MIXED MICELLE Surface TGs are thinned by digestion by pancreatic lipase & bile salts; replaced by TGs from core of droplet. Lamellae decrease & are ultimately lost. Na+/H+ exchanger creates acidic microenvironment 🡪 protonated FFA uncharged (HA) 🡪 absorption AND THEN… Glycerol, short- & medium-chain FA pass through straight to capillaries Enterocytes reesterify lipids (long-chain FA, etc) back to TGs & PLs 🡪 chylomicrons (packaged in Golgi) secreted into lymphatics TG, DG, CE

80. Lipid digestion & absorption.. Factors Affecting Digestion & Absorption The efficiency seems to be associated with the ability to form micelle, which is affected by the degree of unsaturation, chain length, relative concentration of free vs. esterified FA, etc. . . . perhaps, influencing the solubility in bile salt solution! Short & medium-chained FA (< 14 C) are utilized better vs long-chained FA. Unsaturated FA are utilized better than saturated FA. The degree of esterification: Removal of FA - > TG > DG > MG. Absorption - MG > FA. The ratio of unsaturated/saturated FA: AUFA/SFA ratios@ & digestibility Unsat: sat FA & Digestblty

81. Digestion in Ruminants Mouth- fore stomach- small and large intestines Reticulo -rumen Rumination- allows an animal to ingest feed rapidily , then complete the chewing later Steps of the process include: Regurgitation of the feed Remastication Resalivation Reswallowing Eruction - gas belching

82. Digestive processes in ruminants Nonprotein N (NPN) Feed proteins Fats Carbohydrates Cellulose Starches Hemicellulose Sugars Microbial protein (essential AA) Volatile fatty acids (VFA’s) VFA’s RUMEN/ RETICULUM RUP Microbial protein Peptides OMASUM ABOMASUM SMALL INTESTINE Peptides Amino acids Fats Fatty acids & glycerol Glucose Glucose RDP RUP LIVER RDP Glucose = microbial action; = main site of absorption = some absorption RDP = rumen degraded protein; RUP = rumen undegraded protein;

83. Digestion in Ruminants .. Fermentation in rumen & reticulum Microorganisms number in the billions Excess are removed with feed movement and killed by acid in the abomasum Mutually beneficial relationship Digestion is the same after feed reaches the abomasum Microorganisms use starch and sugar for their growth and development Robs the animal of valuable energy sources Produce Volatile Fatty Acids (VFA) which the animal absorbs and converts to energy Acetic Propionic Butyric Methane gas is released through eructation

84. Digestion in Ruminants .. Flow of digesta in ruminants

85. Principles of rumen and post rumen fermentation & protein degradation

86. Principles of rumen and post rumen fermentation & degradation.... Microbial digestion of CHOs in the rumen

87. Energy pathways in the ruminant

88. Digestion in Ruminants… Protein Pathways About 60% of the dietary protein is degraded in the rumen. The remaining 40% escapes to the abomasum End products of protein and NPN degradation: Amino acids Ammonia Excess formed into urea in liver and excreted in the urine Some is returned to the rumen Synthesized amino acids

89. Protein pathways in the ruminant

90. Benefits of ruminant digestion Because of a pre-gastric fermentation, can use feeds too fibrous for nonruminants . Can use cellulose, the most abundant carbohydrate present, as a major nutrient. Can synthesize high-quality microbial protein from low-quality protein, nonproteinN , and recycled nitrogenous end products. Can provide all components of vitamin B complex, provided the presence ofadequate Co for vitamin B12 synthesis. ☛Thus, ruminants can compete successfully with non ruminant grass eaters, and also occupy niches where the grass quality would be too low to support non ruminants

91. Costs of ruminant digestion Spend a large part of animal’s day chewing, i.e., chewing food 4-7hr/day or chewing the cud about 8hours a day. Need complicated mechanisms to keep the fermentation vat working efficiently, e.g.: regular addition of largequantities of alkaline saliva. powerful mixing movementsin the forestomach. mechanisms for elimination of the gases of fermentation (eructation) for:(1) the regurgitation of the cud (rumination), (2) absorption of end products, and (3) onward passage ofportions of the ferment to the omasum Pathways of intermediary metabolism must be geared toward the use of the peculiar end products of fermentation In the case of all carbohydrates & some proteins - Volatile fatty acids ( mainlyacetic , propionic, and butyric acids). Propionic acid - Can be converted to glucose, which is needed during milkproduction and the later stages of fetal growth

92. END OF SECTION 2

93. SECTION III

94. DIGESTIBILITY OF FEEDSTUFFS

95. PURPOSES FOR DETERMINING FEEDSTUFF DIGESTIBILITY Quantify the availability of nutrients Quantify the available energy concentration of feedstuffs Partition metabolism of nutrients in different compartments of the digestive tract

96. DIGESTION TRIALS Standard Protocol Place animal in metabolism stall

97. First 10 to 14 days (Adjustment period) Feed animal to attain 10% waste to determine ad libitum feed intake Do not collect feces or urine Next 5 to 7 days (Collection period) Feed at 90% ad lib intake (Collect weighback if necessary) Collect an equivalent amount of diet daily and add to a composite diet sample daily Collect feces, weigh, collect a 5 to 10% subsample, and add to a composite fecal sample daily (Optional) Collect urine, measure volume, collect a 5 to 10% subsample, and add to a composite urine sample Post-collection Determine DM, chemical composition and/or energy concentration of feed and feces (Optional) Determine chemical composition and/or energy concentration of urine

98. DIGESTIBILITY CALCULATIONS Dry matter intake (DMI) DMI = Average amount of feed offered x %DM Fecal output (FO) FO = Average amount of feces excreted x %DM DM digestibility (DMD) DMD, % = (DMI – FO)/DMI x 100% Individual nutrient digestibility (Example: CP) Protein dig % = (DMI x % CP diet – FO x % CP feces )/(DMI x % CP diet ) x 100% Concentration of digestible nutrient in diet (Example: Protein) Digestible protein, %DM = CP, % of DM x protein dig %

99. LIMITATIONS OF STANDARD DIGESTIBILITY TRIALS Feces composed of undigested nutrients and endogenous materials Endogenous materials Sloughed mucosa cells Bacteria Enzymes and bile salts Therefore, the digestibility percentage determined by a standard digestibility trial should be referred to as the ‘apparent digestibility’ or ‘apparent digestion coefficient’ The ‘true digestibility’ can only be determined if the endogenous materials are quantified and subtracted from the fecal output Inserting and collecting digesta at a cannula in the ileum can be used to avoid errors associated with bacteria Used for amino acid digestibility in nonruminants

100. 2. Limiting feed intake to 90% ad lib will slow rate of passage of digesta in the digestive tract Apparent digestibility coefficients determined in standard digestion trial may be higher than apparent digestion in producing animals

101. Methods to determine digestibility in producing animals Fecal pans Need to know individual feed intake Fecal bags Need to know individual feed intake Digestibility markers Markers Chromic oxide Titanium oxide Acid-insoluble ash Use Feed known amount of marker Collect feces for 3 to 7 days Analyze feces for marker Fecal output = Amount of marker fed per day/ Fecal concentration of marker Feed known concentration of marker in diet Collect feces for 3 to 7 days Analyze feces for marker DM dig. % = (1 – % marker feed /% marker feces ) x 100%

102. Some feedstuffs can not be fed as sole diet Digestibility may be determined as a ‘partial digestion coefficient’ Procedure Feed test ingredient at varying percentages in a diet Determine apparent DM digestibility of each diet Graph (or run regression analysis) of each digestibility on a line vs the test feed ingredient’s concentration in the diet Apparent digestibility of test feed ingredient will be at the intercept Assumption Concentrations of other ingredients in the diet do not affect digestibility of test ingredient No associative feed effects

103. NITROGEN BALANCE A measure of protein gain or loss Measurement: Nitrogen balance = DMI x %N, DM basis – (FO x %N + Urine volume, L x N, gm /L)

104. The estimation of digestibility

105. Rumen & reticulum Omasum Abomasum Easophagus

106. Methods Total tract digestibility

107. In vivo methods 1- Collection method 7 preliminary period 21 collection period ferric oxide ferric oxide *accustom the animal *Clean GIT Time and effort consuming

108. 2- Indicator method In vivo methods 7 preliminary period 21 collection period Stop indicator +indicator 10 18 *The substance may be a natural constituent of the feed (internal indicator) *it may be added to the feed (external indicator ) The indicator must be: *not digestible *not toxic

109. life Fistula = a hole Cannula = a device Ruminant cannula in: esophagus, rumen, abomasum, duodenum, ileum, cecum Non ruminant cannula in: duodenum, ileum, cecum In vivo methods

110. 3- Nylon bag technique *in sacco technique *in situ technique - Based on : depositing separately foodstuff into bags which are incubated into the rumen of an animal fitted with a rumen cannula - The main objective : is to measure the disappearance of dry matter and/or other nutrients - The technique provides a means of ranking feeds according to the rate and extent of degradation of dry matter, organic matter, nitrogen or other nutritional parameters. In vivo methods

111. 3- The nylon bag technique: The nylon-bag technique uses bags (6.5 x 14 cm) made of nylon mesh (30 - 50 mm ) Concentrates …….. 30 mm Roughages ……..50 mm A sample of known weight is tightly sealed in the nylon bags and placed in the rumen of a fistulated animal The zero-hour bags will not be placed in the rumen but will otherwise treated similarly in warm water (in approximately 39°C water for 15 min (thus not in the rumen). In vivo methods

112. 3- The nylon bag technique : All sets of nylon bags expect of 0 hour will be inserted in the rumen periods of from 6 to 120 hours ( suspended below the particulate mat layer in the ventral sac of the rumen ). subsequent determination of the disappearance of the different feed components. Bags are then removed, washed under tap water, dried and the weight of residue determined to determine the amount of nutrient in feed digested. An empty bag should be incubated that serve as a blank for the experimental conditions. during the use of the nylon bag, the pore size of the nylon material, which should be small enough to prevent passage of feed from the bag, but large enough to permit microbial entry to the sample In vivo methods

113. 5 g DM 31 bags In vivo methods

114. 31 bags 39°C water for 15 min The nutrient disappearance of the hay was estimated at 0, 2, 4, 8, 12, 24, 32 and 48 h of incubation In vivo methods

115. In vitro methods

116. Why do you want to use an in vitro technique ? The in vivo methods are stressful The in vivo methods require more labors count bacteria microbial metabolism and growth simulate rumen conditions predict feed quality protein , fiber microbial ecology simulate rumen digestion Test new feed additives before using in vivo In vitro methods

117. In vitro system components flask simple to excruciatingly complex Medium buffer , substrate, other nutrients gas phase In vitro methods

118. 1- Flask Glass is best Hard plastic Not red rubber, silicone tubing 2-Buffers Variations Weller & Pilgrim, Burroughs, Goering Van Soest , Menke , McDougall etc . Bicarbonate , phosphate *Keep pH 6.7 to 6.8 Reducing agents In vitro methods

119. 1- Tilley and Terry method The method includes two consecutive digestion phases the first digestion phase in Tilley and Terry IVDMD, plant materials will be incubated under anaerobic conditions with rumen microorganisms for 48 hours at 39°C. This will followed by a 48 hour acid-pepsin digestion phase (second phase) at 39°C, under anaerobic conditions. In vitro methods

120. 1- Tilley and Terry method (limitation) the method requires fistulated animals to obtain rumen fluid and long incubation periods . conditions of rumen of the doner cow will affect the result The technique is based on the premise that the final residue is similar to the feces voided by animals eating the forages. This assumption is not strictly true, because metabolic fecal N, which is present in in vivo but not in vitro residues, can cause lower protein digestibility in vivo In vitro methods

121. 1- Tilley and Terry method (limitation) The major limitation of the method is that it’s less accurate for tropical forages (poor quality roughages in general) possibly due to slow rates at which poor quality feeds are digested In vitro methods

122. 2- Two-stage Van Soest Involves incubation of ruminal fluid with feed in buffer followed by extraction of undigested residue in neutral detergent, drying NDF residues and finally weighing. The two-stage Tilley and Terry method measures apparent DM digestibility while the Two-stage Van Soest measures true DM digestibility In vitro methods

123. 3- Gas production technique Measurement of gas production in vitro can be used to study the rate and extent of digestion of feedstuffs. Developed to estimate protein fermentation in the rumen. The advantage : It is quick and cheap, and many data can be collected in one run. In vitro methods

124. 3- Gas production technique (limitation) Buffers do not work well and pH drops after 12-24 hr. Used to measure fermentation curves - Assume that production of fermentation gas is proportional to DM disappearance Affected by the condition of the donor cow In vitro methods

125. In vitro methods

126. 4- Batch Cultures In batch culture: it is ready to be inoculated with a culture of micro-organisms, which will multiply, changing the conditions in the medium by using up the nutrients and producing their own waste products . Using rumen fluid as inoculum It is continue for 48-72 h In vitro methods

127. 4- Batch Cultures (limitation) allow only short-term evaluations no possibility for microbial adaptation to the test condition. give an end-point measurement and do not provide information about feed degradation kinetics. In vitro methods

128. 5-Rumen Simulation Technique (RUSITEC ) It is a semi- continuous culture technique. Avantages: allows adaptation conditions for ruminal microbes to test conditions. provide quantitative information about fermentation and digestibility which may help to explain or predict the in vivo results. RUSITEC has been used not only for evaluating feed digestibility kinetics but , for example, also for studying changes in rumen microbial population and growth, feed additives and treatment of grains with acids In vitro methods

129. In vitro methods Rusitec apparatus with 6 fermenter Single fermenter

130. Rumen Fluid Filtrated by 4 layers of medical gauze 600 mL of strained rumen fluid 100 mL of Buffer Diet R.Digesta RUSITEC Procedures 140

131. Fermentation gases

132. Rusitec procedures Add 100 ml of buffer in each fermenter Strain the ruminal fluid with 4 layer gauze Add 600 ml of ruminal fluid for each fermenter and make sure that not being from the same bottle (try to use fluid from different bottles in the same time and also try to keep the fluid worm as possible) Use 1 bag with feed and 1 bag filled with rumen digesta Close the fermenter and make sure that the 3 way valve is closed tight Flush with N 2 FOR 3min Connect the tube with gas bags and make sure that the gas bags are open. Take samples from the rumen fluid for PH,NH3;Protozoa and bacteria also In vitro methods  

133. Formulating Feed Rations

134. Objectives Explain formulating feed rations Demonstrate formulating a basic feed ration.

135. Take into consideration: Class of livestock Weight of the animal Purpose of feeding List of nutrient requirements Feedstuffs available Composition of feedstuffs Calculate ration Check your calculations!!

136. Procedure for ration formulation As you complete the ration, ask the following questions: Did you correct any deficiencies? Is it palatable/physically feasible to feed? What was your cost per pound or ton? List any additions or supplements you add.

137. Why do we do it? Formulating a feed ration is necessary because you may be feeding your animal corn with a crude protein percentage of 9, and the requirements for your animal is 12. So the corn you are feeding does not meet the requirements of your animal. BUT! By doing a doing a feed calculation, you could add a supplement to your corn feed and increase the crude protein to meet the level required by your animal.

138. Formulating Feed Rations Using a Pearson’s Square: Simple way to formulate a feed ration is by using a Pearson Square Set up as follows: Step 1- Get your square

139. Formulating Feed Rations cont. Step 2: Input your information Feed #1 goes here along with its CP% Feed #2 goes here with its CP% CP% you want goes here

140. Formulating Feed Rations cont. Step 3: Subtract both feed sources’ CP% across the square with desired CP% Feed 1 Feed 2 CP%

141. Formulating Feed Rations cont. Step 4: The numbers you get after subtracting will be the parts you need of the two feeds Parts Feed 1 Feed 2 CP% Feed 1 Parts Feed 2

142. Formulating Feed Rations cont. Step 5: Add the two numbers together to get the total parts for the feed ration Parts Feed 1 Feed 2 CP% Feed 1 Parts Feed 2 Total Parts

143. Formulating Feed Rations cont. Step 6: The parts of each feed can be expressed as a percent simply by dividing the individual parts by the total parts and multiplying by 100 Parts of feed 1/total parts (100) = % feed 1 Parts of feed 2/total parts (100) = % feed 2

144. Formulating Feed Rations cont. Step 7: Calculate the kg of each feed you need by multiplying your percent of feed by how many kg of feed you need % feed 1 x kg of ration = total kg needed for ration % feed 2 x kg of ration = total kg needed for ration Final Step - Check your math: kg of feed 1 x original CP% of feed 1 = kg of CP kg of feed 2 x original CP% of feed 2 = kg of CP Add together to get CP%

145. Practice Problem: Two Feed Sources Formulate 480kg. of a complete sheep diet containing 14% CP. Use corn (9% CP) and a supplement (44% CP).

146. What’s being asked? You are trying to formulate a ration for sheep using two supplements that, by themselves, would not meet their needs. You need to mix the feed to get the specified amount of CP and you need 480kg. of the feed.

147. Round 2! A cow is on a feed that requires a ration containing 55% CP. The CP of the two feeds being used, corn and soybean meal, are 22% and 89%. Determine the amounts of feed necessary to form a 148kg ration that meets the requirements of your cow.

148. Remember! Remember your steps: Step 1: Set up and label your square: the labels stay the same going across Step 2: Subtract going ACROSS the square Step 3: Get your total parts Step 4: Find the % of each feed required Step 5: Find the total kgs needed of each feed Check your answer!!

149. PARTITIONING OF ENERGY IN FARM ANIMALS

150. Introduction Lavoisier first demonstrated that oxidation of nutrients was some form of combustion Rubner (1894) first demonstrated that fundamental Laws of Thermodynamics also applied to intact living animal systems Organic matter  processes  CO 2 + H 2 O + energy (released) Understanding energy transforms is only possible when it is converted from one form to another

151. Introduction Energy goes through many cycles and transformations, always with loss of heat can be released at various rates: gasoline can exploding vs. compost pile nutritional energetics involves the study of the sources and transformations of energy into new products (mainly we are concerned with growth or tissue deposition) of all dry matter we consume, 70-90% goes to synthesis of new products

152. Units of Heat Energy The basic unit of energy is the calorie (cal) it is the amount of heat required to raise the temperature of 1g of water 1 degree Celsius (measured from 14.5 to 15.5 o C) it is such a small unit, that most nutritionists prefer to use the kcal (or 1,000 calories) the kcal is more common (it’s what you read in the supermarket as Calories )

153. Units of Heat Energy BTU (British Thermal Unit) = amount of heat required to raise 1 lb of water 1 o F international unit: the joule - 1.0 joule = 0.239 calories or 1 calorie = 4.184 joule a joule (J) is the energy required to accelerate a mass of 1kg at a speed of 1m/sec a distance of 1m

154. Partitioning of energy

155. Energy Terms (total heat production) Basic metabolic rate ( H e E ): heat energy released from cellular activity, respiration, blood circulation, etc. heat of activity ( H j E ): heat produced by muscular activity (locomotion, maintaining position in water) heat of thermal regulation ( H c E ): heat produced to maintain body temp (above zone of thermal neutrality) heat of waste formation ( H w E ): heat associated with production of waste products specific dynamic action ( H i E ): increase in heat production following consumption of feed (result of metab ), varies with energy content of food, especially protein

156. Gross energy or heat of combustion the energy released by burning a sample of feed in excess oxygen (in bomb calorimeter)- dependent on the chemical composition of the feed but it cannot help predict the energetic transformation efficiency, viz. gross energy as such is meaningless in animal production, because it does not take into account any losses of energy during ingestion, digestion and metabolism of feed. In fact, 1 kg of starch has about the same gross energy content as one kg of straw even though the energy in the straw can not be used by pig or poultry due to missing digestive enzymes.

157. Digestible energy DE is the gross energy of feed minus the gross energy of feces. Therefore, this energy system takes into account the digestibility of feed and gives a useful measure of the energy the animal may be able to use. it is easy to determine. But it does not take into account losses of energy in urine and as combustible gases and during metabolism of the feed. These losses vary among feedstuffs.

158. Metabolizable energy ME is defined as the digestible energy minus energy excreted in urine and as combustible gases. By taking into account these losses, metabolizable energy gives a better estimate of the energy available to the animal. ME corrects the digestible energy for some of the effects of quality and quantity of protein for example.

159. Net energy NE is defined as metabolizable energy minus the heat increment, which is the heat produced (and thus energy used) during digestion of feed, metabolism of nutrients and excretion of waste. The energy left after these losses is the energy actually used for maintenance and for production (growth, gestation, lactation). That means that net energy is the only system that describes the energy that is actually used by the animal. the most accurate and unbiased way to date of characterizing the energy content of feed. However, NE is much more difficult to determine and more complex than DE or ME .

160. Total Digestible Nutrient TDN (%) = % dig. CP + % dig. NFE + % dig. CF + (% dig. EE x 2.25) Relationship between TDN and Digestible Energy (DE) 1 kg of TDN = 4400 kcal Digestible Energy = 4.4 kcal/ gram of TDN 1.87 TDN = 8228 Kcal Relationship between TDN and Metabolic Energy (ME) I kg of TDN = 3520 kcal ME = 3.52 kcal / gram of TDN Relationship between TDN and Equivalent Starch 1 kg of TDN = 0.869 starch equivalent

161. Factors Affecting TDN value: % of DM in the feed DM in the feed – TDN Moisture in the feed - TDN Digestibility of DM Digestibility of DM – TDN Amount of Fat in the DM Fat Content - TDN, because % of fat (i.e. EE) is multiplied with 2.25 in the formula Amount of Minerals in the DM % Contents of minerals (i.e. ash) - TDN

162. PROTEIN EVALUATION READING TEXT ON https://www.slideshare.net/swatishukla106/ppt-protein-quality-novel-protein-sources-41385327

163. End of Section 3

164. Section 4

165. Section I V: ANTI-NUTRITIONAL FACTORS IN FEEDS These are compounds found in feeds that have detrimental effects to the animals. Anti-nutritional factors developed in plants as a defence mechanism. The plants needed them to protect themselves from predation. They have different chemical structures and are found in different amounts in different plants.

166. ANFs in feeds ..... i ) Lignin This is a polyphenolic compound, which is a polymer of three derivatives of phenylpropane . There is no one, well-defined compound called lignin. It is a collective designation, which embraces a group of related compounds. It is of interest to us because lignin physically covers plant fibres. In doing so it makes them not reachable by enzymes that normally digest them. It binds to plant polysaccharides and cell wall proteins as well with the same end result. It is found in all fibrous plant materials such as wood products, mature grass and straws.

167. ANF s in feeds ..... Tannins These are polyphenolic compounds similar to lignin. They are more soluble than lignin. Tannin exists in two types. Hydrolysable tannins are more digestible compared to the condensed tannins. They are bitter and therefore reduce feed intake. Its high concentrations may reduce the growth of or they may be toxic to rumen microorganisms. However, at low levels they protect proteins from degradation by rumen microorganisms. They are found in acacia trees and in sorghum. Alkaloids These are heterocyclic nitrogen based compounds with toxic effects to animals. When present they cause gastroenteritis and haemolytic changes in blood. Non-ruminants being easily affected than ruminants. They are present in a few orders in the dicotyledons . The famous dip and poison antidote atropine is an example of an alkaloid. Nicotine is also a common example of these compounds. Alkaloids are found in Tobacco and leaves of cocoa plant. Apart from being poisonous, some have medicinal use. These include the malaria drug, quinine and the famous anaesthesia morphine. The fungus ergot also has alkaloids, which may induce abortions.

168. ANFs in feeds ..... Oxalates These are salts of oxalic acid and are supporting materials for calcium storage and transport in plants. We need to be cautious when feeding animals because the presence of oxalates inhibits calcium absorption and reduces the digestion of plant materials. Oxalic acid and oxalates may lead into intensive scouring and distress. Sources of oxalates include sesame seed hulls. 

169. ANF s in feeds ..... Gossypol This is a yellow pigment, which is a polyphenolic aldehyde. It is an antioxidant, polymerisation inhibitor and its toxic to monogastric animals. Generally a poisoned animal loses weight, loses appetite, labours and struggles breathing and has a number of heart problems. Gossypol also affects membrane permeability. It also reduces the oxygen carrying ability of blood. It has cumulative effects. We should be able to differentiate between free and bound gossypol. This is because it is the free gossypol which active. It is important also that you remember that the free gossypol content of a pressure-extracted feed is less that that of solvent-extracted feed. This is because gossypol is destroyed by heating. The levels are 200 to 500 mg free gossypol per kg for pressure-extracted and 1000 to 5000mg/kg for solvent-extracted. Cottonseed meal and cake contain 0.3 to 20g per kg Dry Matter of gossypol.

170. ANFs in feeds ..... Protease inhibitors These are compounds that prevent the protein enzymes from breaking down the proteins. One of them is Kuntz anti-trypsin inhibitor and the other is Bowman-Kirk chymotrypsin inhibitor. Their effects are against the respective enzymes. Both inhibitors are rendered ineffective by heat. This is the reason for roasting soyabeans and other feeds suspected to have these compounds before feeding them to monogastric animals. The effects of these are not seen in ruminants.

171. ANF s in feeds ..... Goitrogen This is a group of compounds that interfere with the synthesis of thyroxin in the thyroid gland. The end result is lack of thyroxin with the accompanying enlargement of the thyroid gland. The enlargement in this case will occur even if dietary sources of iodine are at levels considered adequate for the animal. The best example of a goitrogen is goitrin found in most members of the genus Brassica. Thiocynate also found in Brassica is also a goitrogen .

172. Goitrogen cntd Goitrin stops the iodination of the amino acid tyrosine to change it to thyroxin. The thiocynate interferes with the uptake of iodine by the thyroid gland. Leucaena contains the toxic amino acid mimosine . This amino acid is converted in the rumen to a compound, which is a goitrogen . Few sources known to contain goitrogens include Kale, cabbage, rape, soyabeans , linseed peas and groundnuts.

173. ANFs in feeds ..... Thiaminases These are enzymes that destroy thiamine into inactive form. This as expected will result in deficiency signs of thiamine. Most sea feed and certain fish contain significant amounts of the enzymes. However , the enzymes are destroyed by heating or cooking.

174. ANFs in feeds ..... Dicoumarol This is an antagonist of vitamin K. It is present in damaged sweet clover hay. Dicoumarol reduces the blood prothrombin content. The presence of this compound in hay and silage causes massive internal bleeding to death in calves.

175. End of section 4

176. Section 5

177. Section v: Current Trends of climate change and Animal Nutrition Feeding the Future: Livestock Nutrition in the Face of Climate Change

178. Content Introduction Impact of Climate Change on Livestock Nutrition Adaptation Strategies for Livestock Nutrition in a Changing Climate Sustainable Livestock Nutrition Practices Policy and Economic Implications Conclusion

179. Introduction Climate change is a complex and multifaceted issue that affects many aspects of our lives, including the food we eat. One area that has received increasing attention in recent years is the impact of climate change on livestock nutrition. As temperatures rise and weather patterns become more unpredictable, the nutritional quality of the plants that livestock feed on can be affected. This , in turn, can have negative impacts on the health and productivity of the animals, as well as the quality of the meat, milk, and eggs they produce.

180. Impact of Climate Change on Livestock Nutrition Climate change has a significant impact on the nutritional quality of livestock feed and the health of animals. As temperatures rise, the quality of forage crops decreases, which can lead to nutrient deficiencies in livestock diets. This is particularly true for protein and mineral content. In addition, climate change can increase the incidence of diseases and parasites that affect livestock health. For example, warmer temperatures and increased humidity provide ideal conditions for the proliferation of ticks and other pests that transmit diseases to livestock. This can lead to decreased productivity and even death in some cases.

181. Adaptation Strategies for Livestock Nutrition in a Changing Climate One effective strategy for adapting to the changing climate is to diversify the types of crops grown for livestock feed . This can help ensure that there is always a sufficient supply of high-quality feed, even in times of drought or extreme weather events. Farmers and ranchers can also invest in irrigation systems and other technologies that can help them better manage water resources and improve crop yields. Another important strategy is to focus on developing more resilient animal breeds that are better able to withstand the effects of climate change. This can include selecting animals that are more heat-tolerant, disease-resistant, and better adapted to changing environmental conditions . Additionally , farmers and ranchers can implement practices such as rotational grazing and improved manure management to reduce greenhouse gas emissions and improve soil health.

182. Sustainable Livestock Nutrition Practices Sustainable livestock nutrition practices can play a crucial role in mitigating the effects of climate change and improving the health of animals. By adopting sustainable practices such as rotational grazing, reducing food waste, and using locally sourced feed, farmers can reduce their carbon footprint and promote biodiversity. In addition to being environmentally responsible, sustainable livestock nutrition practices also have economic benefits . For example, by reducing the use of antibiotics and hormones, farmers can save money on inputs and improve the quality of their products. Consumers are increasingly demanding sustainably produced food, so adopting these practices can also help farmers stay competitive in the marketplace.

183. Policy and Economic Implications The policy and economic implications of climate change on livestock nutrition are far-reaching. As the effects of climate change continue to impact the availability and quality of livestock feed, farmers and ranchers are faced with difficult decisions about how to maintain their herds and flocks. In addition, there are broader economic implications for the industry as a whole. One example of this is the increasing cost of feed due to droughts and other extreme weather events. This can lead to higher prices for consumers and reduced profitability for farmers. Another example is the potential for increased regulation and oversight of the industry in response to concerns about the environmental impacts of livestock production. Despite these challenges, there are also opportunities for innovation and adaptation. By implementing sustainable practices and investing in research and development, the industry can work towards a more resilient and profitable future.

184. Conclusion In conclusion, climate change has significant impacts on livestock nutrition, affecting both the quality of feed and the health of animals. However , there are strategies that farmers and ranchers can use to adapt to these changes, such as implementing sustainable livestock nutrition practices. It is important that we take action to address this issue, not only for the sake of the livestock industry but also for our own food security and the health of our planet. By supporting policies and practices that promote sustainable livestock nutrition, we can help mitigate the effects of climate change and ensure a healthier future for ourselves and generations to come.

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