The principles of feeding farm animals

Front matter

Class <.irfr

Book., . S ^ CopiglitlJ" —

CQEXRIGHT DEPOSm

Preface

This volume is an outgrowth from a class manual written several years ago by the author for the use of elementary students at the University of Illinois in a general course in stockfeeding. Inasmuch as there has been some little demand for the class manual from outside sources, the author has rewritten the original manuscript and added a number of valuable illustrations and tables.

An effort has been made to present the scientific facts underlying the art of feeding animals in such a manner that the book will not only be suitable for use as a text for college courses in general feeding, but will also be valuable to the farmer who has not had a technical education in agriculture. Thus it has been deemed wise to omit many minor details and a large part of the mass of experimental data from which the general conclusions are deduced.

In the first six chapters the author has discussed the scientific aspects of the subject and has attempted to present them in a simple, concise manner so that they may be easily understood, not only by the student but also by the feeder who desires to familiarize himself with the scientific princii3les underlying the art of stock-feeding. A large number of drawings and photographs illustrating points in the discussion should be of gf eat value in this connection.

vi PREFACE

On account of the " back to the land " movement which is sending men from the cities to the agricultural colleges and to the farm, a mere discussion of balanced rations and feeding standards has not seemed sufficient. Consequently the author has presented rather definite rules regarding the feeding of the different classes of live stock 'which, taken in connection with the feeding standards and the discussion of the nutritive value of the different feeds, should enable the inexperienced feeder to formulate at least fairly satisfactory rations. This point has also been kept in mind in treating of the feeding values of the different feeds, and an attempt has been made to make specific rather than general statements regarding the amounts, proportions, and combinations of feeds in the rations of different classes of farm animals. It has also seemed of value to insert illustrations of the principal crops used for feeding.

It has seemed desirable, partly in order to avoid duplication, to discuss the use of each of the principal feeds for the different species and classes of live stock rather than to devote separate chapters to the feeding of the different classes of farm animals. For example, under the discussion of corn, its use is given in the rations of growing cattle, colts, pigs, and lambs ; fattening cattle, hogs, and sheep ; breeding cattle, horses, hogs, and sheep ; dairy cows ; and work horses.

In addition to the discussion of the nutritive value of feeds and rations, the author has given particular attention to their fertilizing values, a phase which is often neglected both by the student and the stockman.

The author is deeply indebted to Professor H. S. Grindley, Dr. H. H. Mitchell, Professor W. C. Coffey, Professor H. P. Kusk, Professor J. L. Edmonds, Mr. W. J. Carmichael, Mr. C. I. Newlin, and Mr. R. S. Hulce of the University of Illinois,

PREFACE vii

to Dr. W. E. Joseph of the Montana Agricultural College, and to Professor J. M. Evvard of the Iowa State College for many valuable suggestions and criticisms, and he extends to them his sincere thanks. He also thanks the Illinois Experinient Station for the use of unpublished data ; and The Macmillan Company, The Chicago Medical Book Company, The W. B. Saunders Publishing Company, Bailliere, Tindall and Cox, Professor H. W. Mumford, United States Department of Agriculture, United States Bureau of the Census, Ohio Experiment Station, Wisconsin Experiment Station, Kentucky Experiment Station, Connecticut Experiment Station, Pennsylvania Experiment Station, Vermont Experiment Station, Missouri Experiment Station, Iowa Experiment Station, Cornell Experiment Station, and Illinois Experiment Station for

the use of illustrations.

SLEETER BULL.

Urbana, Illinois

Introduction

„^ I. The Chemical Composition of Feedingstuffs II. The Chemical Composition of Farm Animals

III. The Digestion of the Nutrients .

IV. The Digestibility of Feedingstuffs . V. Functions of the Feed Nutrients in the Animal Body

VI. Energy in Feedingstuffs and its Uses in the Animal

Body

VII. The Compounding of Rations VIII. The Feed Requirements of Farm Animals

'-'" IX. Grains and Seeds

X. The Cereal By-products XI. The Oil By-products ....

XII. The Packinghouse By-products

XIII. Miscellaneous Concentrates

XIV. The Hays ....

XV. Fodders and Stovers

XVI. The Straws

XVII. Pasture or Forage, and Soil: XVIII. Silage ....

XlX. Miscellaneous Roughages XX. The Efficiency of Rations XXI. The Fertilizing Values of Feedingstuffs XXII. The Valuation of Feedingstuffs .

NG Crops

PAGB

IX

ILLUSTRATIONS

1. Composition of steers from 100 to 1200 pounds. (T. L. Haecker,

Minnesota Experiment Station) 29

2. Porterhouse steak from a prime steer. Note tlie "marbling."

(Illinois Experiment Station) 32

3. Digestive tract of man — schematic. (Paton, Veterinary

Pliysiology, Chicago Medical Book Company) ... 35

4. Stomach of the horse. (Sisson, Veterinary Anatomy, W. B.

Saunders Publishing Company) 36

5. Caecum of the horse. (Smith, Manual of Veterinary Physiology,

Bailliere, Tindall and Cox) 37

6. Head of cow, showing some of the salivary glands. (Sisson,

Veterinary Anatomy, W. B. Saunders Publishing Company) 38

7. Digestive tract of the horse. (United States Department of

Agriculture) 39

8. Stomach of a sheep. (United States Department of Agriculture) 44

9. Cross-section of mucous membrane of the small intestine.

(Jordan, Principles of Human Nutrition, The Macmillan Company) 48

10. Longitudinal section of a villus. (Jordan, Principles of Human

Nutrition, The Macmillan Company) 49

11. Loop of small intestine of the horse during active absorption.

(Smith, Manual of Veterinary Physiology, Bailliere, Tindall and Cox) 50

12. Digestion harness on a pig (Hlinois Experiment Station) . 57

13. These pigs were fed a ration deficient in phosphorus. (Wis-

consin Experiment Station) ...... 78

14. These pigs were fed the same ration as those in Figure 13, with

the addition of phosphorus in the form of calcium phosphate. (Wisconsin Experiment Station) .... 79

15. Abnormal bones from hogs whose rations were low in calcium

(corn alone, and corn and soybeans). (Ohio Experiment

StatioB) 80

xi xii ILL US TRA TIONS

FIGURE

PAGE

16. The ration of these pigs was deficient in the amount and quality

of protein. (Illinois Experiment Station) .... 83

17. The ration of these pigs contained sufficient protein of the proper

quality. (Illinois Experiment Station) .... 84

18. The effect of the amount and kind of protein upon the bones

of growing pigs. (Illinois Experiment Station) ... 86

19. Pigs at the beginning of a 196-day feeding period upon corn

alone. (Kentucky Experiment Station) ' . . . .86

20. The same pigs as shown in Figure 19 after 196 days of feeding

corn alone. (Kentucky Experiment Station) ... 87

21 . Section of bomb calorimeter. (Connecticut (Storrs) Experiment

Station) 94

22. Respiration calorimeter at the Institute for Animal Nutrition,

State College, Pa. (H. P. Armsby, Pennsylvania Experiment Station) 96

23. Cross-sections of haystacks of different shapes showing the

corresponding values for " F." (United States Department

of Agriculture) 117

24. A self-feeder for cattle. (Mumford, Beef Production) . . . 153

25. A self-feeder for hogs. (Illinois Experiment Station) . . 154

26. Corn production in the United States. (United States Census) 158

27. An ear of dent corn. (Livingston, Field Crop Production, The

Macmillan Company) IfiO

28. Cross-section of a kernel of dent corn. (Livingston, Field Crop

Production, The Macmillan Company) .... 160

29. An ear of flint corn. (Livingston, Field Crop Production, The

30. Cross-section of a kernel of flint corn. (Livingston, Field Crop

Production, The Macmillan Company) . . . .161

31. Distribution of oat production in the United States. (United

States Census, 1910) 170

32. Ergot in a head of rye. (Duggar, Southern Field Crops, The

33. A head of barley. (Livingston, Field Crop Production, The

34. Distribution of barley production in the United States. (United

States Census, 1910) 177

35. A head of emmer. (Livingston, Field Crop Production, The

ILLUSTRATIONS xiii

PIGTTRE PAGE

36. A head of spelt. (Livingston, Field Crop Production, The

37. Heads of the principal types of sorghums. (Montgomery, The

Corn Crops, The Macmillan Company) .... 180

38. Seeds of the principal types of grain sorghums. (Montgomery,

The Corn Crops, The Macmillan Company) . . . 181

39. A panicle of rice. (Livingston, Field Crop Production, The

40. Ten varieties of cowpeas. (Piper, Forage Plants, The Mac-

41. Ten varieties of soybeans. (Piper, Forage Plants, The Mac-

42. Pods of cowpeas and soybeans. (Livingston, Field Crop Pro-

duction, The Macmillan Company) . . . . . 184

43. Koot of peanut. (Livingston, Field Crop Production, The Mac-

44. A cotton plant. (Livingston, Field Crop Production, The Mac-

45. Structure of the corn kernel. (Illinois Experiment Station) . 189

46. Section of wheat kernel. (Jordan, The Feeding of Animals,

47. Weeds growing from seed found in a commercial feed con-

taining screenings. (Vermont Experiment Station) . . 200

48. Buckwheat in bloom, (Livingston, Field Crop Production, The

49. Distribution of hay and forage in the United States. (United

States Census, 1910) 233

50. Bed clover. (Livingston, Field Crop Production, The Mac-

51. Production of clover in the United States. (Hitchcock, A Text-

book of Grasses, The Macmillan Company) . . . 235

52. An alfalfa plant. (Livingston, Field Crop Production, The Mac-

63. Distribution of alfalfa in the United States. (United States

54. Arrangements of leaflets of alfalfa and clover. (Livingston,

Field Crop Production, The Macmillan Company) . . 239

55. Alsike clover. (Livingston, Field Crop Production, The Mac-

Xiv ILL us TRA TIONS

FIGURE PAGE

56. Sweet clover. (Piper, Forage Plants, The Macmillan Company) 242

57. A crimson clover plant. (Livingston, Field Crop Production,

58. Field pea. (Piper, Forage Plants, The Macmillan Company) , 244

59. Cowpea. (Piper, Forage Plants, The Macmillan Company) . 245

60. A soybean plant. (Livingston, Field Crop Production, The

6L Hairy vetch. (Piper, Forage Plants, The Macmillan Company) 247

62. Timothy. (Piper, Forage Plants, The Macmillan Company) . 248

63. Production of timothy in the United States. (Hitchcock, A .

Textbook of Grasses, The Macmillan Company) . . 249

64. Common millet. (Voorhees, Forage Crops, The Macmillan

65. German millet. (Voorhees, Forage Crops, The Macmillan

66. Hungarian millet. (Voorhees, Forage Crops, The Macmillan

67. A field of Sudan-grass. (Piper, Forage Plants, The Macmillan

68. Red top. (Livingston, Field Crop Production, The Macmillan

69. Orchard-grass. (Piper, Forage Plants, The Macmillan Com-

pany) 254

70. Bermuda-grass, (Piper, Forage Plants, The Macmillan Com-

pany) 255

71. Field of orange sorghum. (Voorhees, Forage Crops, The Mac-

72. A field of black-hulled vs^hite kafir. (Duggar, Southern Field

Crops, The Macmillan Company) 259

73. Field of milo. (Montgomery, The Corn Crops, The Macmillan

74. Showing seed per acre, approximate time of planting and feed-

ing different soiling crops. (Illinois Experiment Station) . 269

75. Field of velvet beans. (Duggar, Southern Field Crops, The

76. A field of oats and peas. (Voorhees, Forage Crops, The Mac-

77. Panicles of Canada blue grass and Kentucky blue grass. (Piper,

Forage Plants, The Macmillan Company) .... 279

ILLUSTRATIONS

78. Brome-grass. (Piper, Forage Plants, The Macmillan Company) 282

79. Hogging down corn. (Iowa Experiment Station) . . . 284

80. Meadow-fescue. (Piper, Forage Plants, The Macmillan Com-

pany) 285

81. Mangels. (Cornell Experiment Station) 297

82. Sugar beet, (Livingston, Field Crop Production, The Mac-

83. Carrots. (Cornell Experiment Station) 299

84. Rutabagas. (Cornell Experiment Station) .... 300

85. Cassava. (Duggar, Southern Field Crops, The Macmillan

86. Hogs in rape. (Missouri Experiment Station) . . . , 302

87. Kohlrabi. (Cornell Experiment Station) 303

INTRODUCTION

Any study of scientific agriculture should include a study of stock feeding, inasmuch as 15 per cent of the total farm capital of this country is invested in farm animals, and all these animals must be fed. According to the United States Department of Agriculture there are 25,000,000 horses and mules, 59,000,000 cattle, 52,000,000 sheep, and 65,000,000 hogs in the United States. 77.6 per cent of the corn crop, 59.0 per cent of the oats crop, 32.5 per cent of the barley crop, and 80.0 per cent of the hay crop are fed to animals on the farm. These figures do not take into consideration the animals of the cities, The value of these crops is something over $2,270,000,000. or if one includes the horses of the cities, the total feed bill of this country is at least $2,500,000,000 per year exclusive of the enormous am^ounts of money spent for commercial feeds not grown on the farm, such as bran, cottonseed meal, etc. All together the animals of the United States produce about $5,000,000,000 worth of products yearly, — a sum nearly as great as the value of our total crops.

No matter what phase of agriculture a man expects to make his life Vork, whether he is a dairyman, a live stock farmer, an orchardist, a grain farmer, or a market gardener, he is certain to need at least a general knowledge of the feeding of farm animals. There is no type or system of agriculture which does not necessitate the use and, consequently, the feeding of some animals. To the specialist in animal or dairy xviii INTRODUCTION

husbandry, a knowledge of the best feeding practices is of utmost importance.

Within recent years many factors have arisen so affecting the live stock industry that it is imperative that the successful breeder and feeder must have an intimate knowledge of the fundamental, scientific principles underlying the art of stock feeding. The great increase in the value of farm land, especially in the corn-belt, the gradual disappearance of the range, and the consequent increase in the value of feedingstuffs and of live stock require that the stockman take advantage of every aid which science and experience offer in order to make his business a financial success.

There is, in many cases, a large waste in the feeding of our farm animals. Many of our good farmers are feeding rations which although giving good results are. not as economical as others which would give the same results ; others do not obtain the best results although they feed a more expensive ration. Greater efficiency and greater economy in a great many cases will result from the application of a few general scientific principles.

New or unfamiliar crops, as alfalfa, cowpeas, soybeans, sweet clover, rape, Sudan-grass, etc., necessitate a wider knowledge of feeding values. Also the successful feeder must have a knowledge of the feeding values of commercial feeds and by-products from the manufacture of human foods, as tankage, beet pulp, distillers' grains, the oil meals, etc. One or two generations ago the feeds commonly used for live stock were usually restricted to the grains and roughages grown on the farm. However, with the great increase in the value of land, farm animals, and farm crops, knowledge of the feeding value of the farm crops is not sufficient, but the feeder must also be familiar with the feeding value and general adaptability of

INTRODUCTION xix

the large number of by-products on the market, especially as these feeds vary considerably in price and even more in nutritive value. Most economical feeding is therefore only possible when the relative values of these purchased feeds and the farm grown feeds are clearly understood. Oftentimes a man can sell to good advantage a part of the feeds produced upon the farm and buy commercial feeds for his live stock. On the other hand many farmers buy commercial feeds at prices much above their true value. Also the manures from some feeds have a much higher fertilizing value than the manures from others, thus necessitating a knowledge of the fertilizing values of feedingstuffs.

•A partial solution to the problem of the "high cost" of living may be found in rational stock feeding. A large part of our farm crops are unfit for human food. However, by feeding these rough feeds to meat or dairy animals, we may convert an otherwise useless product into the most nutritious of foods. Many farmers, especially west of Ohio, burn tons of corn stover and straw every year because there is no market for them and they have no live stock to eat them. As you will learn later, one-third of the feeding value of the corn crop is in the stover. However, the only way to recover that third and make it fit for human use is to feed it to animals and convert it into meat or milk, or wool. Our soil experts tell us that in order to maintain the fertility of our soil economically we must introduce a legume into the crop rotation. To do this and make the most profit from our land, we must keep live stock in order to convert the roughage of the rotation into human food.

THE PRmCIPLES OF FEEDING FARM ANIMALS

Chapter I

In order for the student of stockfeeding to acquire a thorough understanding of the subject, it is necessary for him to have a general knowledge of the chemical composition of feedingstuffs. The composition of feedingstuffs is quite variable, and their feeding value depends to a large extent upon their composition. When asked concerning the value of a feed mth which one is unfamiliar, one usually refers to its chemical composition, although other factors also have considerable influence, as will be explained later.

Elements. — Chemistry teaches that all vegetable and animal substances are composed ultimately of chemical elements. Of the 83 chemical elements now known, apparently only 12 are of importance from the standpoint of stockfeeding. These are as follows : carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, sulphur, sodium, magnesium, chlorine, and iron.^ Other elements,

^ Dr. C. G. Hopkins, in "Soil Fertility and Permanent Agriculture," presents the following memory key to the elements essential to plant life : "C. Hopk'ns' CaFe, Mg," if "Mg" stands for "mighty good" and "I" is omitted for modesty. If the student then remembers that all animals require salt, NaCl, He has a list of the important elements. B 1 as iodine, fluorine, silicon, aluminium, copper, arsenic, and manganese, often occur in small amounts in plant and animal life, but they are not of sufficient importance in this connection to warrant their further mention.

Compounds. — Although vegetable and animal substances consist primarily of chemical elements, these elements, with the exception of small amounts of oxygen and nitrogen, do not exist in the plant or animal in the free, elemental state, but they occur in combination with one another to form compounds, such as sugar, starch, fat, and water. The compounds which occur in plant and animal Hfe are large in number and vary considerably in their chemical composition, their properties, and their nutritive values. In fact, these compounds are so numerous and varied that the chemist has attempted to simplify their discussion by dividing them into five classes, putting all compounds of similar composition, properties, and nutritive value into the same class. These classes are as follows : (1) water, (2) mineral matter or ash, (3) crude protein, (4) carbohydrates, and (5) fats. The first two classes are incombustible, and are called inorganic compounds, while the last three classes are combustible, and are called organic compounds.

Nutrients. — These classes of compounds often are spoken of as nutrients. Although the term is used rather loosely, a nutrient may be defined as any feed constituent or group of constituents of the same general chemical composition that is capable of liberating energy or serving for the production of tissue in the animal body. In other words, it is any feed constituent or group of constituents which may aid in the support of animal hfe. Thus water, mineral matter, crude protein, carbohydrates, and fats are usually regarded as the nutrients of feedingstuffs.

The elementary composition of these classes of compounds or nutrients is shown in the following diagram, which is a modification of a similar diagram presented by Jordan.^

All vegetable

and animal

matter

WfltPr [Hydrogen ^^*^^ I Oxygen

Oxygen iTi/^t'oro m />

Sulphur lUOrgdULlC

compounds

Phosphorus Carbon

Ash or mineral

Chlorine matter

Sodium Potassium

Calcium Magnesium J Iron

Carbon Hydrogen

Oxygen Nitrogen Sulphur 2 . Phosphorus ^

Organic

Carbon compounds

Hydrogen Oxygen

' Carbon

Fats <

Hydrogen

Oxygen

The average chemical composition of feedingstuffs is given in Table 28 of the Appendix.

Water, composed of the elements hydrogen and oxygen, is present in variable amounts in all vegetable and animal substances. It forms a large portion of the weight of such

1 " The Feeding of Animals," p. 30. ^ Generally. ^ Sometimes.

substances as green plants, fresh meats, and milk, and in many cases it can be detected by sight and touch. Even substances like starch, bran, wood, straw, and corn, which appear to be quite dry, usually contain from 2 to 15 per cent of water. The water content of plants depends upon the species, the degree of maturity, and the amount of moisture in the soil. Thus fresh timothy grass contains about 60 per cent of water, while mangels contain 90 per cent; immature plants contain more water than mature ones; and plants grown in a moist soil contain more than those grown in a dry soil. Water in the plant acts as a solvei^t for the different forms of plant food and transfers them from one part of the plant to another. It also aids in imparting firmness and rigidity to the plant. This function is illustrated well by the withering of a plant when its water is removed by evaporation or drying.

Water in Feedingstuffs. — The stock-feeder should have a knowledge of the moisture content of feedingstuffs for at least two reasons : first, the amount of dry substance in a feed largely determines its nutritive value ; consequently in using feeds which contain large amounts of water, as silage, wet beet pulp, milk, wet brewers' grains, and mangels (stockbeets), one must feed a larger amount than when using feeds which are low in moisture content in order to supply the same amount of dry matter. Second, the keeping qualities of feeds depend largely upon their low water content. Such feedingstuffs as the hays, grains, meals, and oil cakes, when stored in bulk, are very liable to ferment or mold if they contain more than 18 to 20 per cent of moisture. This usually injures their quahty and decreases their nutritive value.

The amount of moisture in a feedingstuff is determined in the chemical laboratory by drying a weighed sample of the feed in a drying oven at a temperature of 212° F. until all the water is driven off. The dried sample then is weighed, the loss in weight representing the amount of water driven off. The percentage of water is obtained by dividing the original weight of the sample into the weight of the water, and multiplying the result by 100.

Table 1. — Percentages of Water in the Different Classes OF Feedingstuffs ^

Oil by-products PackirLghouse products .

Oil-bearing seeds .

Cereal by-products Cereal grains . .

Straws ....

Grass hays Leguminous seeds by-

7 to 11 Leguminous hays . 9 to 15

Stovers and fodders . 8 to 40

7 to 11 Grass pastures . . 62 to 80

8 to 9 Silage 70 to 80

6 to 12 Leguminous pastures 70 to 85 10 to 12 Roots 86 to 91

7 to 16 Milk and milk-prod-

7 to 15 ucts 87 to 94

Table 1 shows the average percentages of water occurring in the different classes of the common feedingstuffs. The data of this table show that the amounts of water in the different classes of feedingstuffs are quite variable. Milk and the root crops contain the largest amounts of water, — 86 to 94 per cent. Pastures and silage also contain large amounts, — 62 to 85 per cent. Stover and fodder contain from 8 to 40 per cent water. The amount may vary considerably, depending largely upon the method of curing. The hays, straws, and legume seeds all contain medium amounts of water, — 7 to 16 per cent, while the cereal

^ These values represent the upper and lower limits of the average water content of the common feedingstuffs included under each class. For an explanation of thi^ classification of feedingstuffs, see Chapter IX.

grains and oil-bearing seeds, and their by-products, and the packinghouse by-products contain the smallest amounts of water, — 7 to 12 per cent.

MINERAL MATTER OR ASH

The mineral matter or ash, as the name implies, is that part of the feed which remains after the combustion of the organic substances. Common ashes are an impure form of mineral matter. The ash consists principally of the elements, potassium, calcium, magnesium, iron, and sodium, in the form of oxides, phosphates, sulphates, carbonates, and chlorides. However, the elements or radicles found in the ash are not necessarily in the same form or combination as those occurring in the living organism. In the unburned substance, some of these elements may occur in different inorganic combinations with each other, or in combination with organic substances. Thus sulphur occurs in many of the proteins, phosphorus occurs in some of the proteins and in other organic substances, and calcium often occurs in combination with organic acids. During the combustion of the feed the organic material is oxidized and driven off, leaving behind these elements in inorganic combination. Further, nitrates and nitrites occur in small quantities in growing plants and in animals, but by ignition in the preparation of the ash these acid radicles are decomposed and driven off while the metals of these salts are combined with other acid radicles.

No parts or products of either plant or animal Hfe are free from mineral matter. It is an essential constituent of both plants and animals. The mineral elements potassium, calcium, magnesium, iron, oxygen, phosphorus, and sulphur are necessary for the proper growth and development of all agricultural plants and, in addition to these elements, sodium and chlorine are essential also for the nutrition of agricultural animals.

The Mineral Constituents in Feedingstufifs. — In feedingstuffs, potassium is found in greatest amoimts in the roughages, as corn stover, hays, and straws. Fairly large quantities are found in the oil by-products, in wheat bran, in milk, in tankage, and in malt sprouts, while the ordinary cereal grains are deficient in this element.

Calcium is especially abundant in bone meal, tankage, and leguminous hays, while the ordinary grains and many of their by-products are deficient. The rations of young growing animals and of dairy cows are liable to be deficient in this element.

Magnesium is most abundant in the oil by-products and in wheat bran. It also occurs in considerable quantity in the legume hays and in the ordinary grains. The straws and roots are especially low in this element.

The quantity of iron in feedingstuffs is very small in all cases, but it is probably always sufficient except under pathological conditions.

The air is the source of the oxygen to the animal body.

Phosphorus occurs abundantly in bone meal, tankage, bran, middlings, oil by-products, and legume seeds. The grains and legurtie hays contain medium amounts of this element, while dried blood, gluten meal, roots, and straws contain only small amounts. The rations of the young growing animal and of the dairy cow are apt to be deficient in phosphorus.

Sulphur probably is found in small but sufficient quantities in all feedingstuffs.

Sodium and chlorine must be furnished to nearly all animals in the form of sodium chloride or common salt, as the ordinary feedingstuffs do not supply these elements in sufficient amounts.

The amount of mineral matter or ash in a feedingstuff is determined by igniting a weighed sample of the feed until all organic matter has disappeared. The residue is ash or mineral matter. The weight of the ash divided by the original weight of the sample, and multiphed by 100, gives the percentage of mineral matter.

Table 2. — Percentages of Mineral Matter in the Different

Classes of Feedingstuffs ^

Milk and milk prod- Oil-bearing seeds . 2.6 to 4.3

Roots 0.8 to 1.2 Stovers and fodders 3.7 to 12.0

Silage 1.1 to 2.8 Cereal by-products 1.0 to 6.2

Grass pastures . . 1.0 to 2.8 Oil by-products . 4.0 to 6.7

Cereal grains . . . 1.4 to 3.0 Grass hays . . . 3.9 to 7.9

Leguminous pas- Leguminous hays . 6.7 to 10.7

tures . . . . 1.3 to 3.5 Packinghouse by- Leguminous seeds . 2.6 to 5.4 products . . . 4.1 to 64.4

Table 2 shows the average percentages of mineral matter in the different classes of feedingstuffs. This table shows that the packinghouse by-products are quite high in ash content, — 4.1 to 64.4 per cent. Especially is this true of bone meal and tankage, meat scrap and blood meal being only fairly high. Leguminous hays contain fairly large amounts, — 7 to 11 per cent, as also do the non-legume hays, the oil and cereal by-products, the straws, the oil-bearing seeds, and the legume seeds, — 2 to 8 per cent.

1 These values represent the upper and lower limits of the average content of mineral matter of the common feedingstuffs included under each class.

As a rule, the cereal grains, silage, and roots, are quite low in ash, — 1 to 3 per cent.

Crude protein includes all the substances of the plant or animal which contain the element nitrogen. In general, crude protein consists of two sub-classes of substances : (1) proteins, often called true protein, and (2) non-proteins, which is an abbreviation for ^' non-protein nitrogen-containing substances."

Proteins. — In every living organism there are present highly complex, nitrogen-containing compounds to which the general name proteins has been given. These substances form the chief part of the sohd matter of the blood, muscles, nerves, glands, and organs of the animal, and occur in smaller amounts in every part of plants, but especially in the seeds. They form an essential part of the protoplasm of every cell, plant or animal. They also are important constituents of the cell wall of all animal cells, and are always present in the fluids which surround the cell. As a nutrient, the proteins occupy an important position, due to the fact that they are the only nutrient which contains nitrogen in forms available to the animal body. Thus, they are necessary not only for the growth and development, but also for the life, of every animal. Water ,^ mineral matter, and protein are absolutely essential constituents of the rations of all animals. An animal soon dies if water, mineral matter, or protein is withheld from the ration. If an insufficient amount of any of these nutrients is given, the animal fails to develop properly, and in extreme cases dies.