***W* 
 
 UNIVERSITY OF CALIFORNIA 
 
 COLLEGE OF AGRICULTURE 
 
 AGRICULTURAL EXPERIMENT STATION 
 
 Reserve Berkeley, California 
 
 POULTRY FEEDING: PRINCIPLES 
 AND PRACTICE 
 
 WALTHER F.HOLST AND WILSON E. NEWLON 
 
 Revised by H. J. ALMQUIST and T. H. JUKES 
 
 BULLETIN 417 
 
 FEBRUARY, 1927 
 REVISED, AUGUST, 1935 
 
 UNIVERSITY OF CALIFORNIA 
 BERKELEY, CALIFORNIA 
 
CONTENTS 
 
 PAGE 
 
 Principles of poultry feeding 3 
 
 Necessity for food 3 
 
 Digestion of food 4 
 
 Nutrients 4 
 
 Proteins 4 
 
 Carbohydrates 7 
 
 Fats 8 
 
 Vitamins 10 
 
 Minerals 13 
 
 Water 14 
 
 Feeds as combinations of nutrients 14 
 
 Digestibility 15 
 
 Total nutritive requirements 16 
 
 Bulk . . 16 
 
 Characteristics of various feedstuffs 17 
 
 Energy concentrates 17 
 
 Barley 17 
 
 Corn 17 
 
 Oats 18 
 
 Sorghums 18 
 
 Wheat 18 
 
 Rice 18 
 
 Watergrass seed 18 
 
 Rice by-products 18 
 
 Wheat by-products 18 
 
 Wheat bran 18 
 
 Coconut meal 18 
 
 Manioc meal 18 
 
 Molasses 19 
 
 Protein concentrates 19 
 
 Fish meal 19 
 
 Meat scraps and tankage 19 
 
 Fresh meat 20 
 
 Milk 20 
 
 Oil-cake meals 21 
 
 Animal versus vegetable protein supplements 21 
 
 Mineral supplements 22 
 
 Salt 22 
 
 Phosphorus 23 
 
 Calcium 23 
 
 Other minerals 24 
 
 Grit 24 
 
 Sources of vitamins 24 
 
 Feeds supplying vitamin A 24 
 
 Feeds supplying vitamin D 27 
 
 Feeds supplying vitamin G 27 
 
 Water 28 
 
 Combining concentrates in poultry rations 28 
 
 Feeding for egg production 30 
 
 Methods and rations 30 
 
 Feed consumption per hen 32 
 
 Feeding for growth 32 
 
 Methods and rations 32 
 
 Feed consumption by chicks 33 
 
 Feeding for special purposes 34 
 
 Feeding of breeding birds 34 
 
 Feeding of molting birds 34 
 
 Feeding birds for finishing 35 
 
 Commercial poultry feeds 36 
 
POULTRY FEEDING: PRINCIPLES AND 
 
 PRACTICE 
 
 Walther F. Holst 1 and Wilson E. Newlon 2 
 Revised by H. J. Almquist 3 and T. H. Jukes 4 
 
 PRINCIPLES OF POULTRY FEEDING 
 
 The production of eggs and market poultry is a process of transform- 
 ing comparatively cheap feeds into high-priced products for human con- 
 sumption. The fowl's body is the agent which effects this transformation. 
 Under the highly specialized conditions of commercial egg production in 
 California, the poultryman cannot expect the greatest efficiency from 
 his birds without a working knowledge of the principles of animal nutri- 
 tion. Poultry feeding should be based on the food requirements of the 
 birds, the nutritive value of the different feeds, and a knowledge of how 
 to use these for the particular purpose in view. 
 
 NECESSITY FOR FOOD 
 
 Although plants can nourish themselves from such simple sources as 
 soil and air, domestic birds, like all other animals, require ready-made 
 nutrients. They utilize these for two main purposes: (1) as building 
 material for the construction of new tissues and their products; (2) as 
 a source of heat and energy. At all times newly formed tissue is needed 
 for replacement of the tissue destroyed by the general wear and tear of 
 the body. Cells (that is, the small units of which the tissues of the body 
 are composed) are constantly being worn out, broken down, and sloughed 
 off. These cells have to be replaced by material from the outside. During 
 certain periods new tissue is needed also for growth and reproduction, 
 that is, for the formation of new body material and reproductive cells. 
 
 The body also needs energy for the production of heat, which is neces- 
 sary for maintaining the body temperature and for all the body activi- 
 
 1 Assistant Professor of Poultry Husbandry and Associate Poultry Husbandman 
 in the Experiment Station. Deceased, January 29, 1933. 
 
 2 Poultry Specialist, Agricultural Extension Service. 
 
 3 Assistant Professor of Poultry Husbandry and Assistant Poultry Husbandman 
 in the Experiment Station. 
 
 4 Instructor in Poultry Husbandry and Junior Poultry Husbandman in the Ex- 
 periment Station. 
 
 [3] 
 
4 University of California — Experiment Station 
 
 ties, including locomotion, blood circulation, respiration, digestion, 
 absorption, and excretion. These activities are the distinguishing char- 
 acteristics of what is called animal life, and all consume energy. 
 
 For these purposes birds need a constant supply of food. If this supply 
 should fail for any length of time, the birds would begin to lose weight, 
 living on and consuming their own body material until death occurred. 
 If, on the other hand, the supply exceeds the demand, that is, more food 
 is provided than is required for these activities, the body has the power 
 to store the excess digested food as body fat. Body fat is nature's pro- 
 vision of a reserve, in case the food supply should fail partially or com- 
 pletely for a short period. 
 
 Food is composed of several distinctly different groups of substances, 
 which are called nutrients. Of these the following six groups are recog- 
 nized : proteins, carbohydrates, fats, vitamins, minerals, and water. 
 
 DIGESTION OF FOOD 
 
 Most of the nutrients cannot be used by birds in the form in which they 
 are supplied in the food. They must undergo digestion, which means 
 breaking them down into their very simplest and most soluble form, so 
 that they can pass through the intestinal wall, be absorbed by the blood, 
 and distributed through the body. Digestion is made possible by the 
 agency of various chemical substances, called enzymes. These are sup- 
 plied mostly in the digestive juices, but partly, also, in ordinary feeds 
 and to a lesser degree by microorganisms in the digestive tract. Complete 
 digestion of whole grains may require from 10 to 15 hours, while diges- 
 tion of ground feed may be completed in as short a time as 2~y 2 hours. 
 
 NUTRIENTS 
 
 Proteins. — Protein is the name of a group of very complex organic sub- 
 stances, which always contain carbon, hydrogen, oxygen, and nitrogen. 
 In addition, proteins usually contain sulfur and frequently phosphorus. 
 These substances are widely distributed in plants, which build them up 
 from simple sources in the soil and air, and in animal tissues, which must 
 derive them directly or indirectly from plant tissues. The thousands of 
 different known forms of protein vary widely in character but have two 
 characteristics in common : they all contain nitrogen in a fairly definite 
 proportion (approximately 16 per cent) and all are composed of certain 
 simpler building stones, the amino acids. 
 
 A bird's body contains as much protein as all other groups of nutrients 
 together, if water is excepted. Twenty per cent of the live weight and 
 practically 50 per cent of the dry weight is protein. It is therefore easy 
 to understand the importance of this group of nutrients in feeding. 
 
Bul. 417 
 
 Poultry Feeding : Principles and Practice 
 
 Of the amino acids which form the proteins, about 22 are known. 
 Certain of the amino acids are more important from the standpoint of 
 feeding practice than others. This is because some of them, such as 
 tryptophane, lysine, and cystine, cannot be built up by fowls from other 
 amino acids, while certain others, such as glycine, can be formed in the 
 bird's body from the excess of other amino acids present. 
 
 Figure 1 illustrates the effects on the body weight of rats of feeding 
 poor proteins, that is, proteins lacking in one or more of the essential 
 
 
 
 
 
 
 
 
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 1 
 1 
 
 
 
 
 
 
 
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 2. J../, 
 
 asfas 
 
 hone 
 
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 Fig. 1. — Comparison of growth on incomplete and complete proteins. 
 (After Mendel.) 
 
 amino acids, and of feeding more complete proteins. In the case which 
 supplied the data, Indian corn was at first the only source of protein. 
 The principal protein of corn, which is called zein, is known to be lack- 
 ing in the two amino acids, tryptophane and lysine. The addition of 
 tryptophane only was sufficient to prevent decreases in body weight, but 
 growth did not begin until lysine was added also. Exactly similar results 
 would be expected if chicks were used. Other grain proteins have similar 
 deficiencies, and so have certain animal proteins, like gelatin. 
 
 To be complete and give the best results as a food, a protein must con- 
 tain all of the essential amino acids. Naturally the necessary amino acids 
 may be provided by a combination of properly chosen incomplete pro- 
 teins. As indicated in figure 2, proteins in the form in which they are 
 present in the feed have to be broken down by digestion into the amino 
 acids, which are soluble and therefore can be absorbed by the blood. The 
 blood carries the amino acids to different parts of the body, where, 
 according to the bird's needs, they are put together again into new 
 proteins, the body proteins. 
 
6 University of California — Experiment Station 
 
 If protein is provided in excess of requirements, the amino acids are 
 formed and absorbed by the blood as usual. In the liver, however, they 
 are deprived of their nitrogen, thus being transformed into one or both 
 of two other classes of nutrients, carbohydrates and fats. The fate of the 
 tissue protein after it is worn out is similar. It is broken down and de- 
 prived of its nitrogen, and the remaining part utilized in the animal 
 
 CRUDE FOOD PROTEINS 
 
 Undigested 
 Food 
 
 Digestive Tract 
 
 Ammo Acids 
 
 Body 
 
 1 
 
 Body Protein 
 
 1 
 
 Amino Acids 
 
 Protein 
 
 Nitrogen Part Carbohydrate Part 
 
 1 1 
 
 Uric Acid j Urea 
 
 Ammonia etc 
 
 Liver 
 
 Glifcoqi 
 
 Fat Rart 
 
 H 
 
 Body Fat 
 
 Muscle Glycogen 
 
 I Burned (Oxidized) \ 
 i -for Heal t Energy 
 
 Egg Fat 
 
 CO z + H 2 
 
 Fig. 2. — Scheme illustrating the use of proteins in the body. This figure, as well as 
 figures 3 and 4, must be taken to illustrate only possible ways of conversion of nutri- 
 ents, and not the proportions in which conversions take place. 
 
 body. The nitrogen thus segregated does not appear in the free form, 
 but is largely split off as ammonia, which is transformed inside the bird's 
 liver into uric acid and urea; these pass out in the urine by way of the 
 kidneys. 
 
 As indicated above, excess protein in feed is not wholly wasted. The 
 nitrogenous part is wasted, but the rest is used as carbohydrates or 
 forms fats. While protein can thus replace carbohydrates or fats to a 
 certain degree, the reverse is not possible, because these latter nutrients 
 do not contain nitrogen and are not capable of taking it up. A lack of 
 protein in a chick ration will retard growth, and a lack of it in a laying 
 ration will retard production. 
 
Bul. 417] Poultry Feeding : Principles and Practice 
 
 Carbohydrates. — These organic compounds contain only three chemi- 
 cal elements: carbon, hydrogen, and oxygen. The last two elements 
 nearly always appear in the same proportions as they exist in water, in 
 fact, the name carbohydrate means carbon-water. The carbohydrate 
 group includes the starches, sugars, pentosans, and celluloses. The cellu- 
 loses, however, are generally classed separately under various headings 
 
 Food Carbohydrates 
 
 Digesti\ 
 
 f Q TracF 
 
 5/rnple 5ugars 
 
 Body 
 
 1 
 
 Undigested 
 Food 
 
 Liver Glycogen 
 
 1 
 
 Body Far 
 
 Muscle 6/c/cogen 
 
 j Burned (Oxidized) [ 
 [76/- fieaf -f Energy 
 
 Egg Far 
 
 CO^H^O 
 
 Fig. 3. — Scheme illustrating the use of carbohydrates in the body. 
 
 such as "fiber" or "crude fiber," in tables giving the composition of feeds. 
 The crude fiber is largely indigestible for poultry. 
 
 In the course of digestion, the carbohydrates, as shown in figure 3, 
 are broken down into the simplest kinds of sugars, the so-called monosac- 
 charids, in which form they are absorbed. The monosaccharids readily 
 combine with the oxygen (which is absorbed from the lungs by the 
 hemoglobin of the blood) ; they are thus oxidized (or burned) to carbon 
 dioxide and water with the production of heat. Upon this heat liberation, 
 as already mentioned, the life processes of birds, as of other animals, are 
 absolutely dependent. 
 
 The scarcity of carbohydrates in the animal body and their prepon- 
 derance in the feeds indicate that they are stored only temporarily as 
 carbohydrates and are either used comparatively soon, serving as fuel 
 for the animal organism, or stored in some other form (fat, see p. 8). 
 They are found stored in certain tissues, however. The body require- 
 ments for fuel vary widely, being high during vigorous exercise and 
 
8 University of California — Experiment Station 
 
 low during rest and sleep. The liver acts as a regulator of this fuel 
 supply. As the blood, with the dissolved sugars, passes from the intes- 
 tines on its way to the heart, it circulates through the liver, where excess 
 sugars are deposited, to be stored in the form of animal starch or glyco- 
 gen. Glycogen is also stored in the muscles. 
 
 After feeding and during rest, this starch may compose as much as 
 15 per cent of the weight of the liver. At other times, as during starva- 
 tion or after vigorous exercise, it may be found to compose as little as 2 
 per cent of this organ. The muscles normally contain about 0.6 per cent 
 of glycogen, the total amount in all the muscles of the body being ap- 
 proximately equal to that in the liver. When any muscle or organ of the 
 body is used, a supply of energy in the form of glycogen is present 
 within the particular muscle or organ of which work is required. The 
 glycogen is broken down and oxidized, setting free the necessary energy. 
 The muscles then immediately begin to draw on the main reserve of gly- 
 cogen in the liver for the replenishing of their supply. The liver in turn 
 receives its replacements from the food. 
 
 Consequently the liver is not only a storage place for but also the 
 regulator of the carbohydrate supply. It stores the excess sugars after 
 meals and later gives them up to the blood, which distributes them to the 
 different body parts according to demand. 
 
 Fats. — These are compounds of an alcohol (usually glycerin) and the 
 fatty acids (commonly, stearic, palmitic, and oleic acid). Like carbo- 
 hydrates they contain only the three elements, carbon, hydrogen, and 
 oxygen. They differ from carbohydrates in that oxygen is contained in 
 much smaller proportions : starch and sugars contain between 49.4 and 
 53.3 per cent oxygen, fats about 11.0 per cent. 
 
 In the digestive tract, as illustrated by figure 4, fats from the food 
 are broken down (digested) to free fatty acids and glycerin, which pass 
 through the intestinal wall, immediately to be recombined into fats. 
 These are taken up by the lymph and passed on to the blood in a sus- 
 pended form. The fats are used for energy purposes, probably being 
 first transformed into sugars, which then combine with more oxygen, 
 producing heat, carbon dioxide, and water. If not needed immediately 
 as a source of energy, they are deposited within the cells and in the adi- 
 pose or fatty tissue. This is found below the skin, in the folds of the 
 abdominal cavity, and as protective layers around certain vital organs, 
 such as the kidneys. 
 
 Body fats are also derived from another source. Since the storage 
 places for carbohydrates, the liver and muscles, soon become loaded to 
 their limit, a transformation process sets in, changing excess carbohy- 
 
Bul. 417] Poultry Feeding : Principles and Practice 9 
 
 drates into fats. Carbohydrates in excess, therefore, produce body fats. 
 Approximately one part of fat yields as much heat or energy as 2Vi 
 parts of carbohydrate. The difference in heat or energy value is due to 
 the fact mentioned above, namely, that fats contain less oxygen than do 
 carbohydrates. The more oxygen present in a compound, the less energy 
 will be liberated on complete oxidation (burning to carbon dioxide and 
 
 Food Fat 
 
 Digestive Tract 
 
 Glycerin + Fatty Acids 
 
 Body 
 
 1 
 
 Undigested 
 Food 
 
 Fat in Blood 
 
 L 
 
 Body Fat 
 
 Burned (Oxidized) \ Egg Fat 
 
 i tbrfieat^ ^f^gy} 
 
 V 
 
 Fig. 4. — Scheme illustrating the use of fats in the body. 
 
 water) . Or stating the reverse, the less oxygen there is present, the more 
 energy will be liberated. 
 
 In the fattening of poultry and other domestic animals, not fats but 
 carbohydrates, are fed in excess. This is because carbohydrates even in 
 large quantities are very easily digested, absorbed, and transformed 
 into fat. Fats, on the other hand, are digested only with difficulty, and 
 are absorbed slowly. The difficulties are such that large proportions of 
 fat in the food may retard digestion and upset the normal metabolism 
 of the other nutrients. Consequently large amounts of fat are always to 
 be avoided in animal feeding. 
 
 Feeds which contain large amounts of fat are apt to become rancid in 
 hot weather. Rancid feed is injurious to poultry. Fats are much more 
 expensive than carbohydrates, and hence do not find their way in quan- 
 tity into ordinary rations. Small amounts of fat, however, are necessary 
 as carriers of the fat-soluble vitamins. Such small amounts are present 
 in nearly all natural foodstuffs. 
 
10 University of California — Experiment Station 
 
 Vitamins. — There are six known members of this group of nutrients, 
 called by the letters of the alphabet, A, B, C, D, E, and G. Recent investi- 
 gations indicate that doubtless there are still others. The physiological 
 importance of the vitamins in life and their main sources are well 
 known. Vitamins are characterized by the lack of proportion between 
 their great importance in nutrition and the extremely small quantities 
 in which they are normally required. The quantities in which they are 
 present in food are far too small to contribute to the body any energy 
 worth mentioning. It is so far unknown whether the vitamins are actu- 
 ally structural components of the body, or whether they are simply 
 catalysts (accelerators) which speed up certain essential body processes. 
 If they are withdrawn from the ration for any length of time, however, 
 the result is inevitably disease (so-called deficiency disease) and eventu- 
 ally death. 
 
 Unlike the other classes of nutrients, which are very stable chemical 
 compounds, many of the vitamins are more or less unstable, which makes 
 their study much more difficult. Because of this instability, care must 
 always be taken to insure an adequate supply of vitamins in poultry 
 rations. When the individual needs have been covered, an excess can in 
 certain cases be stored in the animal tissues. A supply of any of these 
 vitamins beyond that which is needed and can be stored by the body, is 
 either destroyed or excreted. 
 
 Vitamin A (or fat-soluble A) is also called a growth vitamin be- 
 cause one of its main effects seems to be that of promoting growth in 
 young stock. Animals fed on an otherwise perfect ration, but lacking 
 this vitamin, stop growing. Examples of this effect are shown in the 
 growth records in figure 5. Another condition also results, namely an eye 
 disease called xerophthalmia, meaning dryness of the eye. Not only the 
 secretory glands of the eye, but also those of the mouth, nose, and throat 
 dry up. As the secretions of these glands are germicides to some extent, 
 infections in these locations are frequent when the ration is deficient in 
 vitamin A. This condition in birds, sometimes called nutritional roup, is 
 caused by a vitamin-A deficiency and can be prevented or cured by the 
 feeding of substances known to be good sources of this vitamin. 
 
 Plants synthesize a yellow pigment called carotene. It is present in all 
 green parts of all plants, and in certain yellow parts of some plants, 
 such as yellow corn and carrots. Birds change carotene to vitamin A 
 (which is almost colorless) in their livers. Hence birds may get their 
 vitamin-A supply from the carotene of plants, or from fish oils, in which 
 vitamin A has already been converted by the fish from the carotene 
 present in sea plants. Hens store vitamin A in their livers and egg yolks. 
 
Bul. 417] 
 
 Poultry Feeding : Principles and Practice 
 
 11 
 
 The amount stored in the egg yolk depends on the amounts of carotene 
 and vitamin A fed to the hen. 
 
 When vitamin A and carotene are exposed to the air, particularly at 
 temperatures above room temperature, they are very unstable, being 
 rapidly oxidized. For example, if fish oil is not kept in closed containers, 
 the vitamin A in it is soon destroyed. Carotene in plants, such as alfalfa, 
 is fairly well preserved when the curing conditions are favorable; that 
 is, when the drying is accomplished rapidly, but without exposure to 
 sunlight or to excessively high temperatures. 
 
 Fig. 5. — Growth with and without vitamin A. (After Hopkins.) 
 
 Vitamin B is frequently called the antineuritic vitamin. The term 
 vitamin B was formerly used to refer to a vitamin complex including 
 two different factors, both of which promote growth. One factor is now 
 termed vitamin G and will be discussed under that heading. Vitamin B 
 is found in the germ and bran of all grains, and also in fresh vegetables 
 and in green feed, milk, and egg yolk. 
 
 Vitamin B is present in all whole cereal grains and in such of their 
 by-products as bran, which consist of the outer coats. Hence it is pres- 
 ent in every ordinary poultry ration and does not need to be fed in extra 
 quantities by providing special supplements. It is very stable; exposure 
 to air and even moderate temperature does not destroy it. 
 
 A dietary deficiency with regard to this vitamin causes a nervous dis- 
 order in poultry, called avian polyneuritis, which is physiologically 
 equivalent to human beri-beri. Both diseases, the avian as well as the 
 human, develop paralysis of the limbs, at times edema, and finally heart 
 failure. 
 
 Other essential factors of a comparatively unknown nature are asso- 
 ciated with vitamin B and have similar properties. These factors appear 
 to be present in cereal grains. 
 
12 University of California — Experiment Station 
 
 Vitamin C (also called water-soluble C or the antiscorbutic vitamin) 
 prevents the disease known as scurvy. It has been considered of little 
 importance in poultry feeding because past experiments seemed to show 
 that fowls were not affected by a lack of the vitamin in the diet. How- 
 ever, a number of investigators have found an abundance of this vita- 
 min in the livers of birds fed rations containing little or no vitamin C. 
 This might indicate that it was required in metabolism and was being 
 synthesized. 
 
 Vitamin D is known as the antirachitic factor. It is perhaps the most 
 peculiar of these newly discovered substances, since its place may be 
 taken by a purely physical agent- — certain light rays. These rays are 
 usually referred to as the ultra-violet rays or ultra-violet light. They are 
 rays of comparatively short wave length found in sunlight and may be 
 produced artificially by the mercury vapor or the carbon arc lamps. 
 These rays change certain substances in the skin to vitamin D. 
 
 Vitamin D is contained in a few animal fats where it often, but not 
 always, occurs associated with vitamin A. Outstanding sources of vita- 
 min D are various fish oils, like cod-liver oil, sardine oil, etc. 
 
 Vitamin D is now thought to exist in two forms. One of them is very 
 effective for poultry. This form is found in sardine oil and in cod-liver 
 oil. The other form is very effective for rats, but not relatively as effec- 
 tive for poultry. This form is present in certain artificial preparations 
 of the vitamin, such as irradiated yeast, which are used principally for 
 human feeding. 
 
 Lack of this vitamin for growing chicks results in a bone disease 
 called rickets, which is characterized by lameness, swelling of the joints, 
 and bone deformities, Such deformities are caused by a disturbance of 
 the utilization and retention of lime and phosphorus salts (principally 
 calcium phosphate) in the body, whereby these salts are either not de- 
 posited or are deposited in an insufficient amount in the growing bone. 
 Even with an abundance of calcium and phosphorus in the diet, the 
 bird cannot make use of them unless the antirachitic factor (vitamin D 
 or certain light rays) is also provided. A mineral deficiency obviously 
 will have the same result. Unless minerals are present, no minerals can 
 be deposited; but even a large excess of lime and phosphorus cannot be 
 utilized by the bird without the cooperation of vitamin D or the light 
 rays mentioned above. 
 
 Adult birds may suffer from a disease similar to rickets. Laying hens 
 will produce eggs for a certain period regardless of whether vitamin D 
 is supplied or not; if this factor is lacking and calcium utilization there- 
 fore interfered with, the hen will actually deprive her own bones of the 
 
Bul. 417] Poultry Feeding : Principles and Practice 13 
 
 calcium in order to form normal eggs. She may in this way ultimately 
 develop a severe case of calcium-deficiency disease. The crooked breast 
 bones observed in good layers are often a result of the lack of vitamin D 
 and the depletion of the calcium supply in the bones. 
 
 The antirachitic vitamin, although not as unstable as vitamin A, is 
 also affected by prolonged oxidation and high temperature. 
 
 Vitamin E is closely connected with the functions of the reproduc- 
 tive organs of animals. Most of the experimental work done so far with 
 this vitamin has been with rats. A continued deficiency may produce 
 permanent sterility in male rats. Laying pullets and breeding males 
 have been shown to require the vitamin for normal reproduction and 
 hatchability. However, this vitamin is contained in many plants and in 
 the embryos of seeds to such an extent that the fowl's needs seem to be 
 taken proper care of by ordinary rations. 
 
 Vitamin G has been shown by recent investigations to be of great 
 importance in growth and hatchability. Chickens have a high require- 
 ment for vitamin G. Green feed, milk, and eggs are rich in the vita- 
 min. Many commonly used poultry rations are deficient in G, especially 
 if they do not contain milk and alfalfa meal. The use of fresh green feed 
 also helps to meet this deficiency. Pure yeast is a good source, but is 
 expensive. The poultryman can usually supply this vitamin by the use 
 of milk with alfalfa or fresh greens. 
 
 Recent work at this station indicates that vitamin G consists of two 
 substances, both of which are needed by chickens. 
 
 Minerals. — In addition to the foregoing groups of substances, which 
 are all organic compounds, the bird's body also contains inorganic mate- 
 rial. Included in this are the minerals, which are to be found not only in 
 the skeleton but, in smaller proportions, in all organs, tissues, and fluids 
 of the bird's body. It is evident that growing birds need a constant sup- 
 ply of minerals so that they may be enabled to form new bone and other 
 mineral-containing tissue. Just as evident is the necessity of providing 
 laying birds with the essential minerals for egg-shell formation. Experi- 
 ence has, moreover, proved the necessity of supplying all adult birds 
 with minerals, because their tissues are subject to general wear and tear, 
 and must be renewed. 
 
 The parts that the various minerals play in metabolism are little 
 known. Calcium and phosphorus are needed for bone formation, calcium 
 for shell formation also. In addition, calcium is an important constitu- 
 ent of the blood, for it is a necessary factor in coagulation (clotting). 
 Sodium is needed by all plant-eating animals, because it is necessary for 
 the elimination of the excess of potassium contained in the feed. Chlor- 
 
14 University of California — Experiment Station 
 
 ides of sodium and potassium are needed as constituents of the body 
 fluids and tissues. Iodine is required in small quantities for proper func- 
 tioning of the thyroid gland. Iron appears in eggs and is also an impor- 
 tant constituent of the hemoglobin, the chief oxygen carrier of the blood. 
 Besides these, copper and zinc are found in small quantities. The re- 
 quirements are small because the body waste is inconsiderable. Besides 
 acting as building material for the body, the minerals aid in the proc- 
 esses of digestion, absorption, distribution, and excretion. 
 
 Although the organic nutrients, when fed in excess, are stored in the 
 body, such is not the case with minerals. Whatever is not needed for 
 immediate use by the body is soon disposed of through excretion. Evi- 
 dently, therefore, their supply in the food must be continuous. 
 
 Water. — Water is a nutrient of the utmost importance to the body. 
 Besides being an important structural component, water is a necessary 
 agent in practically all body processes, which are chemical reactions 
 between substances in a liquid medium, of which water is the principal 
 constituent. 
 
 The fowl's body is continuously losing moisture through the expired 
 air and the excretions. Laying birds lose additional moisture through 
 the formation of eggs. Therefore water must be provided continuously. 
 The water formed in the body by oxidation of organic nutrients does 
 not cover more than a small fraction of the actual needs. With increasing 
 external temperature the needs for water are correspondingly increased 
 to compensate for the greater loss of water through the lungs. Evapora- 
 tion through the lungs is the principal means of temperature regulation 
 since birds do not possess sweat glands. This is probably the explanation 
 of the commonly observed fact that they are less able to withstand high 
 temperatures than most of the common mammals. 
 
 FEEDS AS COMBINATIONS OF NUTRIENTS 
 
 During the previous discussion, the nutrients have been considered as 
 pure and well-defined substances, which can be accurately identified by 
 chemical or biological examination. This was to explain clearly their 
 individual characteristics and behavior. 
 
 In practical feeding, however, it is not the separate nutrients which 
 are dealt with, but feedstuffs, which are mixtures of them. Neither are 
 the nutrients present in pure form, but as so-called crude proteins, crude 
 fats, etc. The fact that the nutrients are present as a mixture does not 
 affect the underlying principles of nutrition, which govern each one of 
 them separately. Of much more concern is the form in which proteins, 
 carbohydrates, and fats are present. 
 
Bul. 417] 
 
 Poultry Feeding : Principles and Practice 
 
 15 
 
 The proportions in which these nutrients are present can be deter- 
 mined by analysis. Tables of the composition of f eedstuffs give the aver- 
 age percentage of these classes of nutrients in the common feeds, as in 
 table 1. 
 
 TABLE 1 
 Approximate Percentage Composition of Feedstuffs Used for Poultry 
 
 Feedstuff 
 
 Alfalfa meal 
 
 Alfalfa leaf meal 
 
 Barley 
 
 Beans, lima, dried 
 
 Buckwheat 
 
 Buttermilk, dried.. 
 
 Coconut meal 
 
 Corn, Indian 
 
 Cottonseed meal.... 
 
 Feterita 
 
 Fish meal 
 
 Herring 
 
 Whole sardine 
 
 Sardine scrap 
 
 Tuna scrap 
 
 Kafir 
 
 Linseed meal, old process 
 
 Linseed meal, new process... 
 Manioc meal (tapioca meal) 
 
 Meat scrap 
 
 Milk, skim, dried 
 
 Millet 
 
 Milo 
 
 Molasses 
 
 Oat groats 
 
 Oats 
 
 Peanut meal 
 
 Potatoes 
 
 Rice, whole (rough or paddy) 
 
 Rice, hulled 
 
 Rice bran, high grade 
 
 Rice bran, low grade 
 
 Rice polish 
 
 Rye 
 
 Sesame meal 
 
 Soybean meal 
 
 Watergrass seed (wild millet).. 
 
 Wheat 
 
 Wheat bran 
 
 Wheat middlings 
 
 Whey, dried 
 
 Crude 
 protein 
 
 14.3 
 22.5 
 10.0 
 18.0 
 
 70.0 
 68.0 
 62.0 
 56.0 
 10.6 
 35 
 37.0 
 2.1 
 50.0 
 35.0 
 12.1 
 11.1 
 
 16.4 
 12.2 
 44 5 
 2.1 
 8.1 
 9.1 
 12.8 
 
 11 5 
 
 12 
 11 1 
 43.0 
 43 5 
 
 7.5 
 12.3 
 16.8 
 17.6 
 16 
 55 5 
 
 Nitrogen- free 
 extract* 
 
 Crude 
 fat 
 
 35.8 
 
 2.0 
 
 41.2 
 
 3.4 
 
 68.4 
 
 2.2 
 
 66.0 
 
 15 
 
 62.2 
 
 2.2 
 
 40 
 
 6.0 
 
 45 
 
 6.0 
 
 71.0 
 
 3.8 
 
 22.9 
 
 7 
 
 69.1 
 
 2.8 
 
 3.0 
 
 8.0 
 
 30 
 
 8.0 
 
 3.0 
 
 8.0 
 
 3.0 
 
 10.0 
 
 69.9 
 
 2.7 
 
 36 
 
 6.5 
 
 37.0 
 
 2 9 
 
 81.5 
 
 4 
 
 5 
 
 6.0 
 
 49.0 
 
 1.0 
 
 61.0 
 
 4 1 
 
 71.4 
 
 2.9 
 
 50.9 
 
 
 66.0 
 
 5 9 
 
 59.1 
 
 4.7 
 
 23.8 
 
 9.2 
 
 16 3 
 
 1 
 
 64.5 
 
 1.8 
 
 74 5 
 
 2.0 
 
 45.0 
 
 15.0 
 
 40 5 
 
 13 
 
 58.8 
 
 11.6 
 
 73.7 
 
 17 
 
 24 
 
 7 
 
 29.1 
 
 5.0 
 
 590 
 
 4.2 
 
 71.1 
 
 1.8 
 
 53 5 
 
 4 3 
 
 57.4 
 
 5.0 
 
 75.0 
 
 2.0 
 
 25.9 
 
 2.7 
 
 Crude 
 fiber 
 
 30.1 
 12.7 
 6.5 
 
 11.0 
 
 9 
 2.3 
 
 2.3 
 
 8.6 
 8-7 
 1.6 
 3 
 0.0 
 8.4 
 2 5 
 
 1.9 
 11.5 
 
 5 2 
 0.6 
 8.9 
 1.1 
 8.0 
 
 13.0 
 3.2 
 2.1 
 
 6 
 
 7 
 10.4 
 
 2.4 
 9 4 
 5 4 
 
 5 
 
 * Total extractable crude carbohydrates. 
 
 Digestibility. — Although analyses of feeds are of great importance, 
 of still greater importance to the practical feeder is the digestibility of 
 the feed. Such information can be obtained only by actual feeding tests 
 under carefully controlled laboratory conditions. 
 
16 University of California — Experiment Station 
 
 Since different kinds of animals have marked differences in their di- 
 gestive systems, the digestibility will vary for different species and has 
 to be determined for each species (that is, separately for cattle, horses, 
 hogs, chickens, etc. ) . Because of the experimental difficulties, caused by 
 the combined excretions of feces and urine, work with chickens has been 
 carried out on only a very limited scale. Digestibility coefficients ob- 
 tained in experiments with other kinds of animals, even with other spe- 
 cies of poultry, cannot always be applied to chickens; they may be very 
 misleading. No complete fundamental information being available, feed- 
 ing of poultry often has to be based more or less on practical experience 
 and knowledge of the composition of the feeds. 
 
 Total Nutritive Requirements. — By measuring the respiratory gases 
 and other metabolic products and excreta from the bird's body under 
 the different conditions of starvation, maintenance, and production, the 
 basic energy requirements of the bird have been determined. The re- 
 quirements are almost directly correlated with the surface area of the 
 body. Feed requirements per pound of live weight therefore vary with 
 the size of the bird, since the smaller body always has a greater surface 
 in proportion to body weight. In spite of statements frequently made to 
 the contrary, the actual energy requirements of poultry (not laying) do 
 not exceed those of other farm animals or humans on the basis of body 
 surface. On the basis of a given unit of weight, the requirements of an 
 animal increase with decreasing size. Energy requirements during molt 
 and broodiness are practically the same as under ordinary nonlaying 
 conditions. The laying process, involving the formation of eggs, how- 
 ever, requires approximately 80 per cent more energy than simple main- 
 tenance. 
 
 Bulk. — The very fact that the digestible part of the food has to be 
 specially determined indicates that not all of a food is digestible. A part, 
 varying greatly with the different kinds of food, is not digested and is 
 passed out with the droppings. A large part of the undigested food in 
 poultry is always the crude fiber, which as cellulose makes up as much as 
 30 per cent of the walls of the cells of which the grains are composed. 
 Certain other carbohydrates, the pentosans, which are likewise not di- 
 gested to any considerable degree, are present in appreciable percent- 
 ages in the common grains. They comprise about 7 per cent of corn, 6.5 
 per cent of wheat, 10 per cent of barley, 16 per cent of oats, and as much 
 as 25 per cent of wheat bran. 
 
 All poultry rations furnish more or less bulk, a large part of it in the 
 form of crude fiber. The amount of bulk giving the best results has not 
 yet been definitely determined. There appears to be a rather large mar- 
 
Bul. 417] Poultry Feeding : Principles and Practice 17 
 
 gin of safety within which variations do not seem to make much differ- 
 ence. Thus certain rations with as little as 2 per cent and others with as 
 much as 10 per cent crude fiber have given good results. Most common 
 rations, with 6 per cent crude fiber, have more than 6 per cent of bulk 
 because of other indigestible matter. Further, one ration comparatively 
 low in fiber may furnish far more bulk than another containing several 
 per cent more fiber. The bulk in some rations commonly used may be as 
 high as 30 per cent, which is certainly more than is desirable. There is 
 no evidence in support of the prevalent opinion that the presence of 
 bulk is of assistance in "opening up" the rest of the food to digestion. 
 
 CHARACTERISTICS OF VARIOUS FEEDSTUFFS 
 
 In the following pages, each of the commonly used feedstuffs will first 
 be described separately, and then a general discussion will be presented 
 of the considerations which should govern the choice. 
 
 ENERGY CONCENTRATES 
 
 Barley. — In large sections of Europe barley is fed as the only grain, and 
 the results are very satisfactory. In California a number of poultrymen 
 have fed a ration consisting of as high as 75 per cent of barley, getting 
 good results. In sections where barley is favorable in price, it may well 
 be fed as the only scratch grain, and variety provided for by using other 
 grains or their by-products in the mash. Whole barley may be fed to 
 chicks at as early as three weeks of age. Birds raised on other grains do 
 not take easily to barley, but if trained to eat it early enough they like 
 it and consume it as readily as any other grain. 
 
 A fairly good indication of the feed value of different grades of barley 
 is the weight per bushel. Obviously the heavier the barley, the higher, as 
 a rule, is the feed value. The light-grade barley, in order to deserve con- 
 sideration, should be obtainable at correspondingly low prices. Hulled 
 barley has a higher feed value than ordinary barley. The present hulling 
 operation, however, is probably too expensive to make hulled barley an 
 economical feed. Light barley screenings and hulls should under no con- 
 sideration be used as a feed for poultry. 
 
 Corn. — Yellow corn is a valuable grain for poultry, being highly pal- 
 atable, highly digestible, and often reasonable in price. Yellow corn 
 differs from white corn and most other grains in that it provides vita- 
 min A. The amount contained is, however, rather small, 2% ounces of 
 yellow corn per adult bird per day being needed in order to prevent 
 nutritional disease. 
 
18 University of California — Experiment Station 
 
 Yellow corn also contains the pigment (xanthophyll) which gives yel- 
 low color to the skin and shanks of the bird and to the egg yolk. There 
 is not enough of this pigment, however, to make yellow corn an undesir- 
 able poultry feed, even in large amounts, unless fed together with large 
 amounts of fresh or dried greens. 
 
 Oats. — Oats are a desirable feed for poultry, although even heavy 
 oats have a comparatively low feed value because of the large propor- 
 tion of hulls. 
 
 Sorghums. — Kafir, milo, feterita, Egyptian corn, etc., are all com- 
 monly used for poultry feed. Their price, considering feed value, is 
 often such that they should be even more extensively used. 
 
 Wheat. — Wheat is another popular feed for poultry. In feed value it 
 ranks below corn, but above barley and oats. 
 
 Rice. — Rice is now being produced in California in steadily increas- 
 ing amounts. While the superior grades are far too expensive for use in 
 poultry feeding, off-grade paddy rice and screenings, like cracked rice 
 and brewers' rice, can often be obtained at attractive prices. They are 
 very desirable feeds; by some poultrymen they are preferred to almost 
 any other grain. 
 
 Watergrass Seed. — Watergrass seed is a wild millet, which in Califor- 
 nia appears as a weed in the rice fields. The feed value of watergrass seed 
 is above that of oats and slightly below that of barley. It is well liked by 
 birds and should be used to the extent that it can be obtained, provided 
 the price is right. 
 
 Rice By -Products. — Such rice by-products as rice bran and rice polish 
 are very valuable and palatable feeds. Their fat content, however, is so 
 high that they should not, individually or in combination, make up more 
 than 20 per cent of the total ration. Used inside of such a limit, they 
 have been giving very satisfactory results. 
 
 Wheat By-Products. — As feed for poultry, wheat by-products are en- 
 joying great popularity, although they naturally supply nothing not 
 found in whole wheat. Their popularity has resulted in prices which 
 often are too high, considering their feed value. 
 
 Wheat Bran. — Experiments at this station have shown that wheat 
 bran is a useful addition to the ration, and may be advantageously in- 
 cluded, especially in chick rations, when its price is not too high. 
 
 Coconut Meal. — When low in price, coconut meal may be included in 
 the ration to replace from 5 to 10 per cent of the grains. It is best not to 
 replace protein concentrates with coconut meal. 
 
 Manioc Meal. — This meal, also called tapioca flour, is the dried and 
 ground cassava root. Containing more than 70 per cent starch, with 
 
BuL. 417] Poultry Feeding : Principles and Practice 19 
 
 hardly any protein or mineral, it is decidedly an energy concentrate. 
 Properly supplemented, however, manioc meal serves very well as a 
 poultry feed. Because of its floury consistency, an amount larger than 
 10 to 15 per cent of the total ration is perhaps not advisable, although 
 higher proportions have been successfully used by this station both for 
 laying birds and for baby chicks. 
 
 Molasses. — Either cane or beet molasses is a feed commodity that has a 
 distinct value as an energy concentrate. It is, however, entirely lacking 
 in protein. Owing to its high mineral content, a main constituent of 
 which is potassium, it is highly laxative when fed in amounts exceeding 
 5 per cent of the total ration. 
 
 PROTEIN CONCENTRATES 
 
 Fish Meal. — Without question, one of the most valuable protein con- 
 centrates on the market is fish meal or fish scrap. Unless the fat content 
 is far above the average, which is between 6 and 8 per cent, fish meal 
 even when fed in large amounts does not give taste or odor to the eggs 
 or meat of birds to which it is fed. Fish proteins are of the highest bio- 
 logical value and are therefore well suited for supplementing grain 
 rations for poultry. Fish meals, as they are now being manufactured on 
 the Pacific Coast, are practically all made from whole fish or cuts of fish. 
 The cooking of the fish necessary for the removal of the oil is only of a 
 few minutes' duration, and the drying is more and more being carried 
 out at low temperatures under vacuum or by other methods which pre- 
 vent oxidation. Fish meals contain certain desirable elements such as 
 iodine, and further have a comparatively high vitamin-D content. 
 
 Pacific Coast fish meals vary in protein content from 56 per cent to 
 as high as 75 per cent, according to the raw material, whether made 
 from one kind of a fish or another, from whole fish or from fish scraps. 
 The method of manufacture of fish meal is of far greater importance 
 than its percentage of crude protein. Fish meal prepared by vacuum- 
 drying or steam-drying will be more digestible than fish meal prepared 
 by flame-drying, but the percentage of crude protein may be the same 
 in both cases. Furthermore, fish meals prepared from such a source as 
 whole sardines will be of much greater value than if prepared from fish 
 waste. If prepared from anything but fresh raw materials, they should 
 find their use as fertilizers. Fish meals dried with excessive heat do not 
 deserve the same price as high-quality meals. 
 
 Meat Scraps and Tankage. — These are packing-house products which 
 resemble each other closely, the difference being that tankage is al- 
 
20 University of California — Experiment Station 
 
 lowed to contain dried blood and "stick," 5 while meat scraps must 
 consist of dry rendered residues only, to which no blood and stick have 
 been added. Both products represent largely the fat-extracted and de- 
 hydrated residue from inedible portions of slaughtered animals and 
 from the whole carcasses of dead animals. Small quantities are derived 
 from the bullion-cube factories. The protein content of meat scraps and 
 tankage will vary from 45 to 80 per cent, according to the amount of 
 bone contained and the amount of stick and blood added. Meat scraps of 
 high quality are excellent f eedstuffs. Even the same commercial brands, 
 however, may vary widely in quality from time to time with the type 
 of material used and the process of manufacture. The different tissues 
 of the animal body vary widely in nutritive value. 
 
 Fresh Meat. — Fresh meat, such as horse meat, is an excellent feed if 
 acquired and fed under sanitary conditions, which unfortunately is not 
 usually the case. Therefore this product represents a constant menace 
 to the health of the flock. Moreover, because of the high moisture con- 
 tent, the price usually asked is too high. Assuming about the same 
 digestibility for fresh meat as for good meat scrap, the fresh meat 
 would be worth not more than 30 per cent of the value of the dried 
 product, taking no account of the additional labor involved in feeding 
 the fresh meat and the difficulties in distributing it evenly among the 
 birds. 
 
 Milk. — Milk is an excellent poultry feed. Where there is a cheap sup- 
 ply of fresh skim milk or buttermilk, satisfactory results can be obtained 
 with milk as the only protein supplement to a grain or grain-product 
 ration. However, it is usually necessary to restrict the supply of water 
 in order to induce the birds to consume enough milk. 
 
 In spite of the high price of milk and milk products, they are such 
 valuable sources of vitamin G and of proteins of high biological value 
 that it is desirable to include some form of milk in the ration, especially 
 for young birds and breeding stock. Milk is also valuable for stimulating 
 egg production. 
 
 There is but little difference in feed value between fresh milk and 
 dried milk on a dry-weight basis. The modern process of manufacture 
 does not seem to change the quality of the nutrients, so that the value in 
 each case depends on the amount of solids contained. Roughly speaking, 
 1 pound of dried milk is equivalent to 10 pounds of fresh skim milk. 
 Semisolid milk products, provided they are of high quality, will do as 
 well as either the fresh milk or dried milk products. In feed value about 
 
 s Stick is partially evaporated tank water containing water-soluble, protein-decom- 
 position products, gelatin, and other nitrogenous materials of low nutritive value. 
 
Bul, 417] Poultry Feeding : Principles and Practice 21 
 
 3% pounds of the semisolid will equal 1 pound of dried milk or 10 
 pounds of fresh milk. The semisolid or so-called "condensed" milks will 
 frequently be found too expensive as compared with either fresh or dry 
 milk and are often lacking in uniformity. 
 
 There is no difference in value between sweet and sour milk. In order 
 to avoid digestive troubles, the milk should preferably be fed either 
 sweet all the time or sour all the time. The sour milk is generally easier 
 to feed. The acid itself has, contrary to general belief, no specific advan- 
 tage for the bird under normal conditions. Where, as in the case of milk 
 feeding for the prevention or cure of coccidiosis, the lactic acid itself 
 seems to be beneficial, the acid should preferably be formed from the 
 milk sugar by fermentation in the intestines. 
 
 Oil-Cake Meals. — The oil-cake meals are protein-rich residues from 
 coconuts, hempseed, linseed, peanuts, soybeans, etc., which remain after 
 the fat has been removed by high pressure or by extraction with a solvent. 
 
 Coconut meal may be employed in poultry mashes to the extent of 5 or 
 10 per cent in place of an equivalent quantity of grains or grain by- 
 products. 
 
 Hempseed meal is high in fiber and consequently has a low feed value. 
 The protein of hempseed meal seems to be of fair quality. 
 
 Linseed meal is a good feed, being high in suitable proteins. Because 
 of its laxative effect, it should never be added to mash in a higher pro- 
 portion than 5 per cent, Linseed meal is usually too high in price, con- 
 sidering its feed value, to justify its use for poultry feeding. 
 
 Peanut meal is one of the best of the vegetable protein concentrates. 
 Both technical and practical results have verified its large content of 
 protein of high biological value. Its use in this country is of compara- 
 tively recent date, but it has been successfully used in the Orient and in 
 Europe over a long period of years. 
 
 Sesame meal is another recent addition to the oil-cake meals. It is a 
 very desirable feed, containing protein of high biological value. Since it 
 is being produced locally, it will probably more and more replace other 
 vegetable protein concentrates. 
 
 Soybean meal is another very valuable protein concentrate. Soybeans 
 and peanuts are seemingly the only two legumes supplying proteins of 
 high value. Like peanut meal, it has but recently been of any importance 
 in this country. Now considerable quantities are imported; and steadily 
 increasing amounts are also being manufactured in the United States. 
 
 Animal Versus Vegetable Protein Supplements. — Repeated trials at 
 this station have failed to bring about satisfactory growth and develop- 
 ment in baby chicks if more than 25 per cent of the animal protein was 
 
22 University of California — Experiment Station 
 
 replaced by soybean meal protein. In view of this evidence, it seems well 
 not to replace more than 25 per cent of the animal protein with vege- 
 table protein. Even this limited replacement is advisable only provided 
 the vegetable protein is materially cheaper than animal protein. If suit- 
 able vegetable protein concentrates are used, it is of little concern 
 whether one product only is used or several concentrates in combination, 
 variety here seeming to have small value. 
 
 MINERAL SUPPLEMENTS 
 
 Care should always be taken to insure sufficient consumption of min- 
 erals. The best practice is, therefore, to include most of the necessary 
 mineral supplement in the mash. Growing mashes should contain a total 
 of 0.7 to 1.0 per cent of phosphorus and 1.5 to 2.0 per cent of calcium, 
 the ratio of calcium to phosphorus being 2 to 1. A higher phosphorus 
 content than 1.0 per cent will frequently cause "slipped tendons" or 
 deformed hocks in growing birds, especially of the heavier breeds. Both 
 growing and laying mashes will usually be deficient in minerals unless 
 calcium phosphate, calcium carbonate, and a small amount of salt are 
 added. 
 
 A certain part of the minerals needed by the birds is naturally con- 
 tained in the grain and in the protein concentrates in the ration. These 
 products do not, however, provide sufficient sodium, calcium, phos- 
 phorus, chlorine, and iron, particularly for growing and laying birds. 
 The deficient minerals can be easily and cheaply obtained : sodium and 
 chlorine from common salt; calcium from limestone, oystershell, ground 
 marble, hydrated lime, etc.; phosphorus and calcium from fresh bones 
 or bone meal, steamed bone meal, acid phosphate, etc. The iron require- 
 ments are usually taken care of by the iron in the fresh or dried greens. 
 A possible iodine deficiency may be overcome by using fish meal and 
 oystershell. 
 
 There is never any reason for paying high prices for proprietary min- 
 eral supplements, since an adequate supply of suitable minerals can al- 
 ways be provided very cheaply. Moreover, no one mineral mixture could 
 possibly be made to supplement even a minority of mixed feeds in a 
 proper way, because each formula will require an addition of varying 
 kinds and amounts of minerals. Furthermore, there is no basis for pref- 
 erence between the different sources mentioned for the particular min- 
 erals. Therefore it will not be necessary to discuss them all individually. 
 
 Salt. — Finely ground common salt should be added to the mash in the 
 proportion of from a /2 to 1 per cent. Salt stimulates the appetite, aids 
 digestion, and is also required for other body processes. According to an 
 
Bul. 417] Poultry Feeding : Principles and Practice 23 
 
 old superstition, salt is poisonous to birds. Salt, however, is not poison- 
 ous, but when fed in concentrated form, it may be injurious to birds. 
 
 Phosphorus. — It is essential that phosphorus should always be sup- 
 plied in sufficiency. A common source of this element is the calcium phos- 
 phate furnished by animal bones in various forms. A poultry mash 
 should contain at least 2 1 /£ to 3 per cent calcium phosphate, part of which 
 is usually supplied by the animal protein concentrate. 
 
 Steamed bone meal is commonly used for this purpose. Poultry will 
 eat fertilizer bone meal, but considering the methods by which it is ordi- 
 narily produced, and considering the resulting enormous bacterial and 
 mold content, it certainly cannot be recommended for feeding purposes. 
 Only edible steamed bone meal, that is, bone meal which has been 
 promptly and properly sterilized, should therefore be used. 
 
 Fresh green bone is a good source of calcium and phosphorus. It is 
 very readily eaten but contains too much fat to be fed in large amounts. 
 It is extremely difficult to handle and feed in large quantities and at the 
 same time maintain sanitary conditions. As usually fed, an even distri- 
 bution among the members of a flock is difficult to secure. 
 
 Precipitated bone phosphate often contains noticeable amounts of 
 muriatic acid, which is crude hydrochloric acid, and commonly carries 
 traces of arsenic. Lots guaranteed to be free of arsenic serve well for 
 feeding purposes but will ordinarily be found too expensive compared 
 with other sources of calcium phosphate. 
 
 Calcium. — Besides providing phosphorus, bone meal also furnishes 
 calcium, but not in sufficient quantities to satisfy the requirements. 
 Thus it is well known that laying birds need an additional supply for 
 eggshell formation. Recent investigations seem to indicate that a cal- 
 cium-to-phosphorus ratio of 2 to 1 is satisfactory in preventing slipped 
 tendons or deformed hocks in chicks. A phosphorus content higher than 
 1.0 per cent in the growing mash will frequently cause slipped tendons. 
 The optimum calcium-to-phosphorus ratio for laying birds has not yet 
 been determined, but it is certain to vary widely with the rate of pro- 
 duction. 
 
 Additional calcium is logically and commonly supplied in the form of 
 calcium carbonate as found in oystershell, limestone, calcite, etc. It is 
 immaterial which of these forms is used, hence price should be the decid- 
 ing factor; but any source of calcium showing large amounts of mag- 
 nesium should be avoided. 
 
 Whenever vegetable protein concentrates are brought into use, the 
 mineral supplements must be increased, for such concentrates have very 
 low calcium and phosphorus content. 
 
24 
 
 University of California — Experiment Station 
 
 The approximate calcium and phosphorus contents of several com- 
 mon f eedstuffs are given in table 2. 
 
 Other Minerals. — Such minerals as sulfur, sulfur compounds, Epsom 
 salts, etc., are frequently advertised as highly essential for birds. They 
 have never been demonstrated to have any good effect. If birds are sick 
 or out of condition, they need specific remedies. 
 
 Charcoal should also be mentioned in this place. It is frequently rec- 
 ommended and used as a supplement to poultry rations. There is no 
 
 TABLE 2 
 Sources of Calcium and Phosphorus in the Poultry Ration 
 
 Feedstuff 
 
 Alfalfa meal 
 
 Bonemeal, steamed 
 
 Buttermilk, dried 
 
 Fish meal 
 
 Limestone 
 
 Meat scrap 
 
 Oystershell 
 
 Skim milk, dried 
 
 Approximate per 
 cent calcium 
 
 Approximate per 
 cent phosphorus 
 
 10 
 
 30 
 
 13 
 
 3.0-5.0 
 
 39.0 
 
 3.0-10.0 
 
 38.0 
 
 1.3 
 
 0.2 
 14.0 
 
 1.0 
 2.0-3.0 
 trace 
 3.0-5.0 
 
 0.5 
 
 1.0 
 
 favorable experimental evidence to show the benefit of charcoal feeding; 
 on the other hand there is nothing to show that it does any harm. The 
 absorbing power of charcoal has been much overemphasized. Even if 
 present, the absorbing power would be of questionable value. Charcoal 
 feeding for poultry should be given up as an unnecessary expense, just 
 as it has been abandoned in human dietetics, where it was formerly 
 recommended. 
 
 GRIT 
 
 Grit should be given to poultry at all times, in order to enable the birds 
 to grind the feed in an efficient way. Hard grit, such as granite grit, will 
 serve such a purpose better than soft grit like limestone grit, but the 
 latter can be used satisfactorily. Hard grit is absolutely insoluble and 
 consequently does not supply any kind of nourishment, so that it does 
 not take the place of mineral supplements. 
 
 SOURCES OF VITAMINS 
 
 In order to make the poultry ration complete, certain vitamin supple- 
 ments have to be included. The vitamins to which particular attention 
 has to be paid are A, D, and G. 
 
 Feeds Supplying Vitamin A. — Vitamin A is commonly supplied by 
 
Buu 417] Poultry Feeding : Principles and Practice 25 
 
 fresh greens such as alfalfa, clover, kale, chard, lettuce, Sudan grass, 
 green barley, green oats, and young corn. It may be supplied equally 
 well by dried greens or yellow carrots. When depending upon fresh 
 greens as a source of vitamin A, the poultryman has to plan ahead for a 
 regular everyday supply of from 5 to 6 pounds of green feed for every 
 100 birds. Much more should not be fed, as the feed value of green feed 
 is too low to justify the expense. An excess of green feed also makes the 
 egg yolks dark, since it is the main source of the pigment xanthophyll. 
 Tests of various fresh greens as a source of vitamin A have shown very 
 little difference in value. Therefore the green feed which can be pro- 
 cured most economically at any particular time or place should be used. 
 
 Alfalfa can generally be depended upon during a large part of the 
 year. It should preferably be cut when young and tender because the 
 woody stems of the mature plant make it less digestible. The stems are 
 also low in vitamin-A content. 
 
 In many sections of California, kale is depended upon for the green 
 feed. Some poultrymen use the whole plant and run it through a feed 
 chopper. A better practice probably is to feed the leaves only, as they 
 are the most valuable part, and as the plant under those conditions will 
 give continued growth and production. 
 
 The preparation of green feed by the sprouting of grains is inevitably 
 accompanied by a loss of feed value, since a. destruction of the protein 
 sets in almost simultaneously with the beginning of germination. A loss 
 of 20 to 30 per cent of the protein is thus an immediate result, with a 
 further, almost complete, destruction soon following. Not only the pro- 
 tein is affected, but also the starch is broken down, disappearing at the 
 approximate rate of 2 per cent a day for the 10 days. Without consider- 
 ing the cost of labor, the sprouting of grains for the purpose of supply- 
 ing fresh greens for poultry is therefore an uneconomical practice. It 
 should further be remembered that all imperfect or injured kernels 
 when prepared for sprouting are greatly exposed to molds, some of 
 which may be very toxic. This fact probably explains the common report 
 that leaving out the feeding of sprouted grains will reduce mortality in 
 a flock. 
 
 Precautions should be taken to avoid access of the laying hens to 
 cheeseweed or mallow, for it has recently been shown at this station that 
 this plant, when eaten by hens, is a common cause of the "pink white" 
 deterioration of storage eggs. Cheeseweed is often found in poultry dis- 
 tricts, along roadsides and at the edges of fields. It is also likely to be 
 present in products such as dried alfalfa when these are not kept free 
 from weeds. Deterioration of this type will also be caused by other 
 
26 University of California — Experiment Station 
 
 plants, notably "California windbreak," hollyhock, and cottonseed meal 
 or kapok meal. 
 
 Alfalfa hay, alfalfa meal, or alfalfa-leaf meal at times provide more 
 convenient and economical vitamin- A supplements for poultry than do 
 the fresh greens. In all cases any of the three products, assuming a high 
 quality, can be used satisfactorily as at least a partial substitute for the 
 fresh greens and can probably be used as a complete substitute if used in 
 sufficient amounts. If cured under proper conditions, the vitamin-A con- 
 tent of the plant is not much lowered by the process. The ideal conditions 
 are rapid drying without long exposure to the sun. Quick curing will 
 yield a product of bright-green color. Bleached-out products, that is, 
 those which have lost their green color and look yellow or brownish, 
 should never be used as a source of vitamin A. 
 
 The whole alfalfa hay is fed on the floor or in the racks. Either way 
 the birds will pick off the tops and the leaves. The stems, which have but 
 little feed value, will be left in the litter. 
 
 Alfalfa meal and alfalfa-leaf meal may have an advantage over hay 
 in that they can be included in the mash. Thus they are uniformly dis- 
 tributed and fed without waste. Which of these products to use is more 
 or less a matter of personal judgment; the leaf meal is nothing else than 
 whole alfalfa meal from which a certain part of the coarse stems have 
 been removed by sifting. 
 
 The vitamin-A requirement of birds will be met by including 8 per 
 cent leaf meal or 10 per cent whole alfalfa meal in the ration, if it is of 
 good quality. If whole hay is used, about 2 pounds per 100 birds should 
 be fed per day, to allow for possible waste and uneven distribution. 
 
 Still another source of vitamin A has been found to be yellow carrots. 
 Yellow carrots have proved to be equivalent to fresh greens for this pur- 
 pose. They have not been popular as a poultry feed because there is a 
 common belief that birds do not relish them. Like any new feed, birds 
 have to become used to them, but they do so quickly. Yellow carrots can 
 sometimes be produced more cheaply than fresh greens and they also 
 have the advantage that they can be stored for a time. The yellow pig- 
 ment of carrots is carotene, which does not color egg yolks. 
 
 The last vitamin-A supplements to be considered are the fish oils. 
 These oils are primarily used as sources of vitamin D; however, they 
 also provide additional amounts of vitamin A when fed in freshly mixed 
 feeds. They cannot economically be used as a complete substitute for the 
 vegetable sources of vitamin A. It should be recalled in this connection 
 that vitamin A in fish oil is easily destroyed. Ordinary untested com- 
 mercial oils vary widely and are undependable as a source of vitamin A. 
 
Bul. 417] Poultry Feeding : Principles and Practice 27 
 
 Even tested oil should never be mixed into feeds and stored, as it then 
 rapidly loses its effectiveness with regard to vitamin A. 
 
 Feeds Supplying Vitamin D. — If an abundance of direct sunlight is 
 available, no further provision of vitamin D in the diet may be needed. 
 However, as a precaution, additional vitamin D may well be provided 
 in all rations. The most practical way to do this is to use a fish oil, such 
 as California sardine oil or cod-liver oil. Vitamin D will be needed by 
 young stock spending a considerable part of the time indoors in the 
 early part of the year because of cool weather or rain, and in the summer 
 because of heat. It is therefore always advisable (at least in most sec- 
 tions of California) to feed some form of vitamin D to young chicks 
 during the first 6 to 10 weeks of their life. Older birds need vitamin D 
 during long-continued cloudy or foggy weather. Laying birds also need 
 this additional supply of vitamin D during seasons of very heavy pro- 
 duction and late in the season, when the evidence of poor calcium util- 
 ization can often be observed in the poor shell texture of the eggs pro- 
 duced. 
 
 One-half of 1 per cent or one-half pint of good cod-liver oil or sardine 
 oil which has been proved to contain the necessary amount of vitamin D, 
 added to 100 pounds of the mash supplies sufficient vitamin D for birds. 
 Lower levels of the "fortified" or concentrated vitamin-D oils may also 
 be used. 
 
 Tests at this station have shown that good grades of cod-liver or sar- 
 dine oil provide adequate amounts of vitamin D when used at the % per 
 cent level, even under conditions where no other source of vitamin D or 
 of sunlight is available to the birds. As vitamin D is far more stable than 
 vitamin A, fish oils as sources of vitamin D can well be mixed into 
 feeds commercially, without any danger that vitamin D will be de- 
 stroyed quickly. As mentioned previously, particular light rays present 
 in direct sunlight (not passed through ordinary glass), or in light from 
 special lamps replace vitamin D; but it is not practical on poultry farms 
 to provide these ultra-violet rays artificially from lamps. 
 
 Feeds Supplying Vitamin G. — Alfalfa meal, in addition to supplying 
 vitamins A and E, also furnishes considerable vitamin G. Outside of 
 green feed, it is probably the most economical source of vitamin G for 
 poultry. Pure yeast and liver are the most potent sources, but owing to 
 their excessive cost they are not recommended. Milk is also a good source 
 of vitamin G. The vitamin-G content, together with the highly digestible 
 protein in milk, is largely responsible for the excellent growth obtained 
 when milk is present in chick rations. Very little vitamin G is contained 
 in grains. 
 
28 University of California — Experiment Station 
 
 Recent work at this station indicates that a combination of milk with 
 alfalfa (or green feed) gives better results than are obtained with milk 
 alone or with alfalfa (or green feed) alone. 
 
 WATER 
 
 It is essential that birds should at all times have access to clean, fresh 
 water, except when milk is given as the only protein supplement, in 
 which case no water need be given. The best way to insure a continual 
 supply of fresh water is to have running or dripping water in a trough 
 or fountain which should be so constructed that the overflowing water 
 does not wet the surrounding litter or ground. Damp soil furnishes an 
 ideal medium for the development of worm eggs. 
 
 COMBINING CONCENTRATES IN POULTRY RATIONS 
 
 The requirements of the various body processes, such as growth and egg 
 production, must be met adequately and without waste by the different 
 feed commodities in the poultry rations. 
 
 The common fowl is by nature mainly a grain eater ; through evolu- 
 tion its whole digestive system seems to have adapted itself to the quick 
 and efficient handling of grains and similar feedstuffs. Poultry feeding 
 therefore is properly based on grains and their by-products as the main 
 supply of nourishment. Only such additions to the main feed are made 
 as are required to complete the ration. 
 
 The grains to be used in building up a poultry ration should be those 
 which are available at a reasonable cost, because starch, the main con- 
 stituent of value in grains, is essentially the same whether obtained from 
 one grain or another. Consequently there is no "best" grain for poultry. 
 Further, the exact combination of grains is of only slight importance. 
 The kinds of grains, and also the proportions of each kind, to be used at 
 any one time should largely depend upon price conditions. 
 
 A variety of grains or grain by-products is by no means essential for 
 successful feeding of either growing chicks or laying birds. Time after 
 time chicks have been raised or birds kept in good condition on one 
 grain only, when it was properly supplemented. Chickens in this respect 
 behave very much like other farm animals. Hogs, for instance, do well 
 on either corn or barley as the only grain. If, however, a variety of 
 grains or grain by-products can be used without adding too much ex- 
 pense to the ration, the variety has one advantage. As previously ex- 
 plained, poultry rations should change according to price conditions. 
 When one grain has been fed as the only grain, a change to a new grain 
 is likely to be too extreme and may temporarily throw the birds off 
 
Bui,. 417] POULTRY FEEDING : PRINCIPLES AND PRACTICE 29 
 
 feed. On the other hand, a change of any one constituent of a ration com- 
 posed of three or more grain by-products can be made without danger of 
 detrimentally affecting the birds. 
 
 A further assumed advantage of a variety of feeds is palatability, 
 which is supposed to be helpful in obtaining an optimum feed consump- 
 tion. A palatable feed is one appealing to the taste. The term is fre- 
 quently misused with reference to poultry feeding, attributing palat- 
 ability to poultry feeds where only familiarity is involved. Generally 
 speaking, all common feedstuffs if they are sound and "sweet," are pal- 
 atable to chickens. This lack of discrimination is explained by the low 
 stage of development of the organs of smell and taste in the fowl. Thus 
 while most feedstuffs are palatable to chickens, which will freely eat 
 feeds to which they have been accustomed, they are sometimes sensitive 
 to abrupt or extreme changes in feed. Where they have not been used to 
 yellow corn, it is at first nearly as hard to get them to eat the new feed 
 as to change them from corn to barley, or from barley to oats. This fact, 
 however, does not justify the classification of corn or barley or any other 
 grain as an unpalatable feed. Chickens habitually like what they are 
 used to and mostly dislike anything else until they have become familiar 
 with it. As a general rule, birds may be more easily trained to eat wheat 
 or corn, than barley or oats. Whether this can be explained by the fact 
 that the hard hull is difficult for the digestive tract to take care of at 
 first is not known. Sometimes that seems to be the explanation, because 
 barley or oats softened by soaking or grinding, seem to be consumed as 
 eagerly as any other grain. 
 
 Any feed tending to upset normal digestion and thereby putting the 
 bird out of condition cannot rightfully be classed as unpalatable, since 
 the lower feed consumption is the direct result of the effect on the bird 
 rather than of the palatability or lack of palatability of the feed. For 
 example, rye in appreciable amounts will decrease feed consumption. 
 
 Physical consistency, if too fine, will seriously affect consumption. A 
 ground feed should therefore be of fairly coarse consistency. Where 
 economic conditions make the use of a fine commodity advisable, it is 
 well to counterbalance the one fine feed by the inclusion of others that 
 are correspondingly coarse. 
 
 Although grains are the basis of the feed, they are not a complete 
 feed for poultry kept for commercial purposes. The proteins of common 
 grains are inadequate as to kinds and amounts. The grains are further 
 deficient in certain minerals, certain vitamins, and water. The grain 
 ration for birds must therefore be supplemented with water, vitamins, 
 proteins, and minerals. Because the protein concentrates are usually 
 
30 University of California — Experiment Station 
 
 available in the form of meals or scraps, which cannot easily be fed in a 
 mixture with the whole grains, the poultry ration is customarily divided 
 into two parts by supplying the supplements in the form of a mash. 
 
 For the sake of convenience, the mash is commonly composed in such 
 a way as to make the proportions of the different nutrients about right 
 when grains and mash are fed in equal amounts. In such case a certain 
 amount of ground grains and possibly grain by-products must always 
 be added to the concentrates in order to establish the proper protein 
 content. 
 
 Suitable mineral concentrates can conveniently be included in the 
 mash. This is in order to insure at all times consumption of the right 
 kinds and proportions of minerals for growth and egg production. 
 Water and certain vitamin supplements are commonly fed separately. 
 
 FEEDING FOR EGG PRODUCTION 
 
 In feeding laying birds, there are two main objectives: the first is to 
 maintain body weight and the second to supply the nutrients required 
 for the formation of eggs. With hens in 50 per cent production, approxi- 
 mately 57 per cent of the total feed intake is required for maintenance. 
 Naturally, then, there is an increased food requirement with an increase 
 in production. 
 
 Methods and Rations. — During recent years the practice of feeding 
 all the grain ground and mixed together with the mash in equal propor- 
 tions is being advocated for laying birds. There are definite objections 
 to such a practice. The nutritive requirements of the same flock are not 
 the same at different times, much less the requirements of the different 
 individual birds. Feeding mash only, leaves no opportunity for varia- 
 tion without changing the proportions in the mixture, and thus makes 
 frequent changes for the flock impractical and variations by the indi- 
 viduals impossible. The feeding of grains and mash separately enables 
 the individual bird to influence its own ration by eating more of one or 
 the other, thereby more or less meeting its individual needs. 
 
 Prices of the various feeds as well as their nutritive value should be 
 considered in deciding the particular ones to be used in the ration. In- 
 formation on the composition of feeds is given in table 1, page 15, of this 
 bulletin. 
 
 Any of the following mash formulas will give satisfactory results 
 when fed with equal amounts of grain. Calcium carbonate in any of the 
 forms previously described, that is, ground limestone or oystershell, 
 should be provided separately in addition to any of the following 
 mashes used. 
 
Bul. 417] Poultry Feeding : Principles and Practice 31 
 
 LAYING MASH 1 
 
 Pounds 
 
 Ground grains and grain by-products 69% 
 
 Fish meal (65 per cent crude protein) 12 
 
 Dried milk . 5 
 
 Alfalfa-leaf meal 8 
 
 Bone meal 2 
 
 Ground limestone or ground oystershell 2 
 
 Salt 1 
 
 Sardine or cod-liver oil Mj 
 
 100 
 LAYING MASH 2 
 
 Pounds 
 
 Ground grains and grain by-products 66^2 
 
 Fish meal (65 per cent crude protein) 10 
 
 Vegetable protein concentrate (soybean meal, sesame meal, etc.) 5 
 
 Dried milk 5 
 
 Alfalfa leaf meal 8 
 
 Bone meal 2 
 
 Ground limestone or ground oystershell 2 
 
 Salt 1 
 
 Sardine or cod-liver oil % 
 
 100 
 LAYING MASH 3 
 
 Pounds 
 
 Ground grains and grain by-products 69^2 
 
 Fish meal (65 per cent crude protein) 7 
 
 Meat scrap (50 per cent crude protein) 7 
 
 Dried milk 5 
 
 Alfalfa leaf meal 8 
 
 Bone meal 1 
 
 Ground limestone or ground oystershell 1 
 
 Salt 1 
 
 Sardine or cod-liver oil Mj 
 
 100 
 LAYING MASH 4 6 
 
 Pounds 
 
 Ground grains and grain by-products 68% 
 
 Fish meal (65 per cent crude protein) 12 
 
 Vegetable protein concentrate (soybean meal, sesame meal, etc.) 6 
 
 Alfalfa leaf meal 8 
 
 Bone meal 2 
 
 Ground limestone or ground oystershell 2 
 
 Salt 1 
 
 Sardine or cod-liver oil % 
 
 100 
 These mashes should be hopper-fed and kept before the birds at all 
 times. Feeds are ordinarily given to poultry in dry form. There seems 
 to be no justification for feeding moistened or cooked feeds. 
 
 By grains and grain by-products in these mashes are meant ground 
 grains such as wheat, yellow corn, barley, sorghums, and oats, and mill 
 
 s This formula is suggested to provide a low-priced laying mash. It is not recom- 
 mended for breeders. Fresh greens should be fed daily when this mash is used. 
 
32 University of California — Experiment Station 
 
 feeds such as wheat bran, wheat middlings, rice bran, and rice polish. 
 This part of the ration may consist of one such feed commodity only, but 
 more commonly consists of a mixture of several of them. According to 
 prices, such mixtures may for instance be equal parts of corn, wheat, and 
 barley, or wheat, oats, and sorghums. It is an advantage to make formu- 
 las in such a way as to avoid too much splitting of sacks in mixing. 
 
 On chemical analysis these mashes will show a crude protein content 
 varying with the different feed commodities included. With whole 
 ground grains as a source of energy and with fish meal as a source of 
 protein, the crude protein content will be about 17 per cent. Consider- 
 ing the wide variation in biological value and digestibility of the vari- 
 ous feed proteins, it should be clearly understood that too much em- 
 phasis should not be put on the exact crude protein analysis. Thus a poor 
 feed may show considerably higher protein content than another to 
 which it really is inferior. 
 
 If fresh greens are fed as the only source of vitamin A, they should 
 be fed daily in amounts of 5 to 6 pounds per 100 birds per day. Whole 
 alfalfa hay can be fed in racks or in the litter at the rate of about 2 
 pounds per day for the same number of birds when fresh greens or 
 alfalfa meal are not fed. Alfalfa meal or leaf meal should be included in 
 the mash to the extent of at least 10 per cent and 8 per cent respectively, 
 if used as the only source of vitamin A. 
 
 Feed Consumption per Hen. — The total feed consumption of a Leg- 
 horn bird per year will be from 80 to 90 pounds, varying with digesti- 
 bility of the ration and the production of the bird. Mash and grain con- 
 sumption are about equal over a period of a whole year, but will vary at 
 different times, according to the rate of production. (See table 3.) 
 
 FEEDING FOR GROWTH 
 
 There is no fundamental difference between a laying ration and a grow- 
 ing ration for poultry, both having to furnish essentially the same re- 
 quirements : protein, energy, vitamins, minerals, and water. 
 
 The protein requirements of the rapidly growing chick (that is, up to 
 the age of 14-16 weeks) are higher than those of the laying hen. The 
 optimum protein intake for baby chicks during the first ten to twelve 
 weeks should be near 20 per cent of the ration. The protein requirements 
 decrease as the rate of growth progressively slows down. At the same 
 time carbohydrate requirements increase in direct proportion to the 
 increasing size of the animal. 
 
 Methods and Rations. — Contrary to the situation with laying birds, 
 where individual variations in production make it desirable to feed 
 
Bui* 417] Poultry Feeding : Principles and Practice 33 
 
 grain and mash separately, in the case of growing birds uniformity of 
 requirements makes it more advisable to provide a single feed mixture 
 that furnishes the different constituents in the proper proportions. For 
 this reason chicks should be started on an all-mash feed with whole grain 
 omitted until about the sixth week, when the habit of eating mash has 
 been established and growth is well under way. The following all-mash 
 rations are recommended for starting chicks. They are also recom- 
 mended as growing mashes to be fed with grains after the sixth week. 
 
 CHICK MASH 1 
 
 Pounds 
 
 Ground grains and grain by-products 74 
 
 Fish meal (65 per cent crude protein) 12 
 
 Dried milk 5 
 
 Alfalfa leaf meal 5 
 
 Bone meal 1 
 
 Ground limestone or ground oystershell 2 
 
 Salt \ 
 
 Sardine or cod-liver oil \ 
 
 100 
 CHICK MASH 2 
 
 Pounds 
 
 Ground grains and grain by-products 73 
 
 Fish meal (65 per cent crude protein) 8 
 
 Meat scrap (50 per cent crude protein) 6 
 
 Dried milk 5 
 
 Alfalfa leaf meal 5 
 
 Ground limestone or ground oystershell 2 
 
 Salt \ 
 
 Sardine or cod-liver oil \ 
 
 100 
 
 Additional shell or limestone should not be fed because this will affect 
 the calcium-phosphorus ratio. 
 
 These mashes should be fed without any scratch grain for the first six 
 weeks, after which grains can be gradually introduced and fed in in- 
 creasing amounts in addition to the mash. 
 
 In feeding chicks, the mash should always be kept before them in open 
 hoppers, starting as soon as they are placed under the brooder. One 
 4-foot hopper accessible on both sides should be provided for each 100 
 chicks. Additional hopper space will be required as the chicks grow 
 older. The grains should also be hopper-fed and may be kept before the 
 chicks at all times after they are three months old. 7 
 
 Feed Consumption by Chicks. — Feed consumption by chicks will vary 
 with the palatability and adequacy of the ration being fed, as well as 
 
 7 Persons interested in more detailed information about brooding are referred to : 
 Newlon, W. E., and M. W. Buster. Brooding and pullet management. California Agr. 
 Ext. Cir. 28 : 1-27. Revised 1933. 
 
34 
 
 University of California — Experiment Station 
 
 with the breed of chicks and brooding conditions. Leghorns up to six 
 weeks of age will consume on the average between IV2 and 2 pounds of 
 feed per bird. Approximately 20 to 25 pounds will be consumed up to 24 
 weeks. (See table 3.) 
 
 TABLE 3 
 
 Approximate Consumption of Feed by Chickens. 
 
 Basis 
 
 Sex 
 
 Age 
 
 White Leghorns 
 
 Rhode Island 
 
 Reds and 
 
 Plymouth Rocks 
 
 Cumulative total to age given 
 
 1 
 
 Both 
 
 sexes 
 
 Female 
 only 
 
 < 
 Fir 
 
 weeks 
 
 4 
 8 
 12 
 
 16 
 20 
 24 
 28 
 32 
 36 
 
 pounds per 100 
 birds 
 
 92 
 360 
 
 747 
 
 1,190 
 1,690 
 2,240 
 2,820 
 3,420 
 4,030 
 
 23 
 8,400 
 
 pounds per 100 
 birds 
 
 96 
 400 
 840 
 
 1,380 
 2,020 
 2,740 
 
 26 
 
 
 
 
 9,480 
 
 
 
 
 
 
 
 FEEDING FOR SPECIAL PURPOSES 
 
 Feeding of Breeding Birds. — The production of hatching eggs as far 
 as feeding methods are concerned, is ordinarily attained by the same 
 methods as that of commercial eggs. Frequently birds from which the 
 eggs are collected for hatching purposes are fed less protein in order to' 
 keep production down to some extent. The benefit of this practice is 
 doubtful. 
 
 Better hatching eggs are obtained when milk, either fresh or dried, is 
 included in the feed. Increased hatchability has also been obtained from 
 the use of fresh greens, and it is advisable to include them in the breed- 
 ing-stock rations. However, satisfactory results can probably be ob- 
 tained from the use of some form of dried alfalfa if used in sufficient 
 quantities. A quantity constituting at least 10 per cent of the mash is 
 suggested. A liberal supply of vitamin-A and vitamin-D supplements 
 in any of the forms recommended should always be provided. 
 
 Feeding of Molting Birds. — Ordinarily not all birds in a flock are 
 molting at the same time. Special consideration in the feeding of molt- 
 ing birds therefore is effective only if the molters are separated from the 
 other birds. In this case the molters, if they have the proper weight, do 
 not need as much feed as laying birds, but they should be fed well. 
 
Bul. 417] Poultry Feeding : Principles and Practice 35 
 
 Feeding Birds for Finishing. — Finishing or "fattening*" feeds are de- 
 signed for the improvement of color, texture, and flavor of the flesh of 
 table poultry. Such feeds are not complete in all dietary respects and 
 can be used for only a limited period of one to two weeks, according to 
 the condition of the bird. They are commonly composed of ground 
 grains supplemented with liquid milk or dried milk plus water to make 
 a feed of soup-like consistency. 
 
 Yellow corn or barley has recently been shown to produce better 
 texture of poultry meat than does wheat or oats. Corn and barley also 
 seem to favor the deposition of fat in the muscles rather than in the 
 fatty tissues, while wheat and oats do the reverse. On the other hand, 
 unless hulled, barley cannot be used to a large extent because of its high 
 fiber content. Furthermore, much yellow corn cannot be used when a 
 white finish is desired. 
 
 A certain proportion of animal protein is very essential in producing 
 economical gains during a finishing period. The most satisfactory source 
 of animal protein for this purpose is some form of milk or buttermilk, 
 either liquid, condensed, or dry. The liquid, unconcentrated milks con- 
 tain only about 10 per cent of solid matter and must be used in larger 
 quantities in accordance with their lower solids content. A part of the 
 milk may be replaced with a good-quality meat scrap or fish meal. The 
 total animal protein content of the finishing feed should be at least 5 
 per cent, and where meat scrap or fish meal are used, their proportion 
 should be computed on the basis of their approximate protein content. 
 It is essential for good results to retain at least 5 per cent of dried milk 
 in the feed. The following is an example of a finishing feed formula : 
 
 Pounds 
 
 Ground yellow corn 35 
 
 Ground whole barley 35 
 
 Ground oat groats or oatmeal 15 
 
 Dried skim milk 15 
 
 Water to the consistency of a thick soup. 
 
 The mixture is commonly fed from wooden troughs, two or three times 
 a day, as much as the birds will completely clean up at a feeding. It is 
 important not to feed too much at a time, or the birds will lose appetite. 
 Leftovers should not be used, for wet feed spoils very quickly. 
 
 This is a branch of the poultry industry which can for several reasons 
 be better undertaken by people who specialize in this particular field. It 
 needs particular skill and experience, and can be more efficiently under- 
 taken on a large commercial scale near the market than in small lots 
 on individual ranches at a distance from the market. 
 
36 University of California — Experiment Station 
 
 COMMERCIAL POULTRY FEEDS 
 
 For many years commercial feed mixtures have had a large place in the 
 poultry industry of California. This fact seems to indicate that they are 
 serving a very useful purpose. Whether in a given case it is better for 
 the poultryman to mix his own or to purchase ready-mixed feeds is 
 largely an economic question. 
 
 The feed dealer has the advantage of buying f eedstuffs and mixing 
 feeds in large quantities. Not infrequently he can lay his products down 
 in the poultryman's feed house as cheap or cheaper than the latter can 
 by doing his own mixing. This leaves the poultryman free to devote his 
 whole time to the management of his flock. 
 
 The decision as to whether commercially mixed or home-mixed feeds 
 are to be employed in a given instance is a matter of business judgment 
 and common sense, provided always that the principles outlined above 
 have been followed reasonably closely. 
 
 It has been pointed out and indeed emphasized that there is no one 
 best ration. Any ration which provides the proper kinds and proportions 
 of nutrients as economically as possible is a good ration. There is no 
 reason to believe that anyone can do more than this. There does not 
 appear to be much foundation for extravagant claims concerning secret 
 formulas or particular substances. 
 
 30m-9,'35