>????*?? 1 ELEMENTS OF DAIRYING | ^ 1 I JOHN WrOECKER | ???????? SF -"7)^9 o Class xa. r %2i3. Book ._a\,^9- CopyiightN^. COPYRIGHT DEPOSIT. Elements of f^aiF-^ing. JOHN W. DECKER. PROFESSOR OF" DAIRYING, OHIO STATE UNIVERSITY. ILLUSTRATED. ) ) 5 5 3 3 1 :> } 9 • / Columbus, Ohio t Published by the Author. 1 O O 3 . ALt, RIGHTS RESERVED, Sy T) COPY a I C0I»YR10HTKD BY JOHN W. DECKER, 1903. PRESS OP THE BERLIN PRINTING COMPANY, COLUMBUS, OHIO. PREFACE. The American Dairy School had its rise in 1891. The instructors had no precedents to fall back upon. A system of laboratory and classroom work had to be evolved. In other words dairying had to be put into pedagogic form. Classroom work was necessarily in the form of lectures, and the lectures have been taking the form of text-books. These books have been writ- ten for a tv\^ofold purpose ; first, for those in the class- room, and second, for the public. This volume has fol- lowed this course. For several years the author has used many notes in lectures before his classes and in public addresses. He believes that such a book used as a nucleus around which he can build will enable the stu- dents to get a firmer and wider grasp of the subject than by lectures alone, and at the same time he believes that the dairy public is looking for such a treatment of the subject. During the past fifteen years a great many facts about milk and its products have been learned. These facts have been set in order and constitute the science of dairying. Other books have been written to cover the field of cheese making, milk testing and dairy bacteriology. No attempt has been made to duplicate those books in this volume, but those things that form the foundation of dairying have been considered. The book has there- fore been named "The Elements of Dairying." TABLE OF CONTENTS. PAGE. Preface 3 Chapter, I. — Introductory 9 1. Dairy Products Staple Articles. 2. Dairying in Great Britain. 3. Rise of the Factory System. 4. Extent of Business in United States. 5. Some Historical Facts. 6. Dairy Business Changing. 7. Effect of Frauds. Chapter II. — The Secretion of Milk 14 8. Mammals. 9. Udder Foreshadowed in Lower Animals. 10. High Development of Udder. 11. Structure of Cow's Udder. 12. Milk Veins. 13. Quality of Udder. 14. Form of Udder. 15. Theory of Milk Secretion. 16. Milk a Secretion. 17. Selection of a Cow. Chapter III. — Water and Solids of Milk 27 18. Composition of Milk. 19. Average Milk. 20. Efifect of Length of Lactation Period. 21. Effect of Breed. 22. Legal Standards. Chapter IV. — Milk Fat 32 23. Chemical Composition. 24. Saponification. 25. Difference Between Butter Fat and Oleo. 26. Tests for Oleo. 27. Color of Milk. 28. Fat Globules. 29. Numbers in a Drop. 30. How Counted. 4 Table of Contents. 5 31. Relative Size of Globules. page. 32. Per Cent, of Fat in Milk. 33. Effect of Breed. 34. Strippings Compared With Fore Milk. 35. ElTect of Excitement of Cow. 36. Effect on Fat of Showing at Fairs. 37. Highest Testing Normal Milk. Chapter V. — Milk Solids Not Fat 43 38. Ash. 39. Proteine Compounds. 40. Caseine. 41. Caseine and Albumen, How Separated 42. Milk Sugar. 43. Sugar, How Obtained. Chapter VI. — The Physical Properties of Milk 47 44. Physical Condition of Milk. 45. Specific Gravity. 46. Lactometer. 47. Creaming of Milk. 48. Viscosity. 49. Law Governing Creaming. 50. Definition of Cream. 51. Effect of Temperature Upon Creaming. 52. Shallow Setting. 53. Dilution Creaming. 54. Creaming Under Air Pressure. 55. The Centrifugal Separator. 56. Factors Affecting Centrifugal Separation. 57. Durability of Separators. 58. Theory of Churning. 59. Varieties of Churns. 60. Effect of Temperature Upon Churning. 61. Advantages of Rich Cream. 62. Churning Cream From Strippers* Milk. 63. Reason Cream Thickens Before Breaking 64. Viscosity Affected by Condition of Fat. 65. Viscogen. 66. How to Use Viscogen. 67. Whipping Crean. 68. Beaten Cream. Taule of Contents. 69. Skim Milk. page. 70. Butter Milk. 71. Artificial Butter Milk. Chapter VII. — Butter and Cheese 63 72. History of Butter and Cheese. 73. Butter. 74. Over-run. 75. Renovated Butter. 76. Cheese. 77. Food Value of Cheese. 78. Yield and Quality of Cheese as Affected by Milk. Chapter VIII. — Contamin.\tion of Milk 70 79. Flavor of Milk, How Afifected. 80. Bacteria. 81. Germicidal Properties of Milk 82. Growth of Bacteria. 83. Acidity of Milk. 84. Putrefactive Bacteria. 85. Pathogenic Bacteria. 86. How to Combat Bacteria. 87. Keep Bacteria Out. 88. Milkers. 89. Sterilization. 90. Pasteurization. 91. Two Types of Pasteurizers. Chapter IX. — Teisting Cows 81 92. The Cow's Milk. 93. Some Jersey Records. 94. Columbian Exposition Test. 95. Holstein-Friesian Tests. 96. Impossible Over-run. 97. Guernsey Tests. 98. Value of Testing Cows. 99. How to Proceed. 100. Tests of Single Milkings Unreliable. 101. Professor Farrin^ton's Experiments on Averages 102. Milk Flow and Richness Combined. 103. Value of Pedigree. 104. Unusual Test of Duchess of Ormsby. 105. DifTerence Between Mean and Average. Table of Contents. 7 PAGE. Chapter X.— Market Milk 90 106. Food Value of Milk and Cream. 107. Ancient Methods of Milk Delivery. 108. Cans vs. Bottles. 109. Milk Tickets. 110. Market Terms. 111. Aerated Milk. 112. Certified Milk. 113. Standardized Milk. 114. Standardizing from Cream and Skim Milk. 115. Standardizing from Two Qualities of Milk. 116. Value of Milk and Cream on Fat Basis. 117. Modified Milk. 118. Objectionable Feature of Cow's Milk for Babies. 110. Methods of Modification. 120. Efifect of Water in Cow's Milk. 121. Walker-Gordon Laboratories. 122. Rubber Nipples. 123. Filling Prescriptions. 124. Effect of Food on Baby's Health. 125. Market Cream. 126. Condensed Milk. 127. Condensed Milk for Babies. Chapter XI. — Dairy Refrigeration 104 128. Field of Dairy Refrigeration. 129. British Thermal Unit. 130. Latent Heat. 131. Ineffectiveness of Running Water. 132. Artificial Refrigeration. 133. Insulation Important. 134. Freezing Mixtures. 135. Ice Cream. 136. Ice Cream Fillers. 137. Frozen Junket. 138. Mixing Cream. 139. Expansion. 140. Freezing in Open Kettles. Experiment Station Bulletins and Reports 110 Dairy Literature 115 CHAPTER L INTRODUCTORY. 1. Dairy Products Staple Articles. Milk, butter and cheese have been staple products in the whole history of the human race, but the past cen- tury, and especially the last fifty years, has seen a re- markable development in the dairy business. 2. Dairying in Great Britain. The British Islands produced considerable butter and cheese, but the demand for these products soon ex- ceeded the home supply and nearby European countries as well as America, Australia and New Zealand began to send in supplies. Danish butter is now standard in that market, and Normandy supplies French rolls. By the invention of artificial refrigeration, products from far-ofif countries are delivered in fresh condition. 3. Rise of tlie Factory System. The factory system sprang up in America and a large trade grew up, and with the opening up of trade in China and other Asiatic countries American dairy products are finding a new demand. But their occu- pancy of that field is to be strongly contested. Russia is also progressing in the dairy business, and Siberian butter and cheese which meet American butter and cheese in the English market, will meet it again in Asia under much more favorable conditions for Russia. 9 10 Ele:\i£xts of Dairying. 4. Kxteiit of Bui!iiiieN»( iu United States. There are in the United States 1T,1U5,22T milch cows valued at $516/711,914, and an army of about 1,700,000 men are required to care for them, while enough more are engaged in manufacturing and hand- ling dairy products to run the number up over 2,000,000, There are over 8000 creameries, beside several thou- sand cheese factories, Wisconsin alone having about 1600. These cows if put in single file, allowing ten feet of space for each animal, would make a line 32,-115 miles long, or would form a procession ten abreast from New York to San Francisco. They give annually 7,266,392,674 gallons of milk, of which 3,751,107,944 gallons is made into butter, with a skim milk residue of 30,969,147,186 pounds, worth $60,000,000. 5. Some Historical Facts. In 1810, ten years after settling the Western Re- serve in Northeastern Ohio, cheese was carted to Pitts- burg for barter. In 1820, Harvey Baldwin, 19 years of age, started with five tons of cheese, made near Aurora, by boat for New Orleans, but sold it out at Wheeling, Cincinnati and Louisville. About 1835, Charles R. Harmon took six tons of cheese to Fort Dearborn (now Chicago), but went back to Milkwaukee, then of 75 inhabitants, and sold it. About 1852, Mr. Harmon bought cheese five days from the hoop and cured it. The factory system started in Oneida County, N. Y. In 1851, Jesse Williams and his sons, residing on different farms, brought their milk together to be made into cheese. Introductory. 11 In Ohio the first factory was built by Mr. Budlong at Chardon, Geauga County, in 18(50. The second one was built in 1861 by Mr. Bartlett at Munson, Geauga County, and the third by John I. Eldridge in 18G2 in Aurora Township, Portage County. In 18G3, Hurd Bros, built one at Aurora Station, and after that the factory system developed rapidly. In Wisconsin the factory system started with a factory built in 1864 by Chester Hazen at Ladoga, Fond du Lac County, and one near Watertown, built by Stephen Faville. The creamery business started later on the gathered cream plan. Wagons driven over long distances gath- ered up the cream which was churned at the creamery. In 18T9 a DeLaval separator was exhibited at the London Dairy Show\ The committee on awards re- ported it as "a very interesting invention, but thought that it would never become practical in large dairies." It has since revolutionized the butter business and made large creameries possible. The Babcock milk test, in- vented in 1890, has also brought about many changes as it pointed out unnecessary losses. The largest creamery in the world is the Continen- tal at Topeka, Kansas. It has 300 skimming stations in Kansas, Colorado and Oklahoma, beside several hun- dred individual shippers of cream, and in 1902 made 8,000,000 pounds of butter. On February 15, 1872, seven men, W. D. Hoards Stephen Faville, W. S. Green, Chester Hazen, H. F. Dousman, A. D. Faville, and H. C. Drake, organized the W^isconsin Dairymen's Association. There were then no through lines of railway to New York, there "being four different gauges of track ; cheese had. to be 12 Elements of Dairying. transferred from one car to another and large bills for cooperage were sent in^ and the cooperage bill became the regular thing. The freight rate from Wisconsin to New York was two cents a pound. Through the efforts of W. D. Hoard, agent of the Wisconsin Dairymen's Association, a rate of one-half cent in refrigerator cars was secured. This marked the beginning of a rapid development of the factory system in the west, and indeed upon the factory system of the whole country. 6. Dairy Business Cliaiigiiig. But the dairy business is changing. Many large cities are calling for milk and cream as well as for butter and cheese. Long milk trains run half across the state to supply New York City. Chicago draws its supply from a hundred and fifty miles around, and Cleveland and Pittsburg compete for their supplies, Pittsburg some- times going within thirty-five miles of Cleveland for milk. Many cheese and butter factories in these terri- tories cannot compete with the higher prices for milk for consumption, and the character of the business is therefore changing. Trolley lines are also playing a part in the change. The dairy business in the meantime is growing. 7. Effect of Frauds. This chapter will not be complete without reference to the battle with frauds. Skim cheese is made with the expectation of selling it for full cream ; filled cheese made bv substituting foreign fat for butter fat almost ruined the business in Wisconsin, and lost the best of the British trade for the Ignited States and it has never been regained. Colored oleo was assumed to be as good as Introductory. 13 butter, and was sold for it in such enormous quantities that its output equalled in 1901 the capacity of 1600 creameries. But the producers of dairy products, together with the injured consumers, have asked for fair legislation and have secured the filled-cheese law and the oleo law of 1902. The United States Navy that carries the flag to dis- tant parts of the world also carries the finest creamery butter put up in three-pound tins. What better thing do American sailors deserve? CHAPTER IL The Secretio]S[ oe Milk. 8. Maiunials. A large class of animals known as nianniials secrete a liquid for the nourishment of their young until, the young are able to find food on their own account. The milk is secreted in glands of more or less prominence in the different species, and this gland is termed the mam- mary gland or udder. It is probably a modification of the sweat glands of the skin. 9. Udder Foreshadowed in Louver Animals. The udder is foreshadowed in lower types of ani- mals, and a gradual development can be traced until the highest development of the gland is found in the domes- ticated dairy breeds of cows^ the extreme development being brought about by the encouragement of nature by man. In the Ornythorycus, "the glands consist of about 200 club-like tubes opening at two points close together on the surface of the skin. The secretion exudes and the young lick it off from the hair." "In the Marsupials, the glands are more com- pacted and small follicles are formed, into which a num- ber of these ducts enter. Each follicle, of which there are ten to twenty in number, empties through a separate duct upon an eminence upon the surface." This eminence is a rudimentary teat. In the sow, the mare, the ewe, the cow the development is increas- ingly pronounced. 14 The Secretion of Milk. 15 10. Hig^li Develoimient of Tdcler. A. W. Bitting, in an article in the Twelfth Annual Report of the Indiana Experiment Station^ from which we quote freely, says that he has dissected a cowl's udder weighing" forty-one pounds six ounces. A Holstein Friesian cow in Wisconsin is reported to have measured nearly six feet around the udder, or within two inches of her heart girth. Cows have been reported to have secreted over a hundred pounds of milk in a day, — their own weight in less than two wrecks, and over ten tons in a year. 11. Striictiire of Co^v's Udiler. The udder of the cow is one large gland with four distinct quarters. It is suspended from the abdominal w^alls in a hbrous capsule, and is held together by fibrous tissue. A longitudinal fibrous partition divides the udder along the median line very distinctly into two halves. Dr. Bitting has shown by injecting colored liquids through the teats, that the halves are again very dis- tinctly divided into quarters, and that only that milk produced in any quarter can be drawn from the corre- sponding teat. A longitudinal section of a quarter and teat shows that the opening of the teat is guarded with a sphincter muscle. A cavity through the length of the teat is lined by folds of the tissue when empty, and just above the teat is another cavity known as the milk cistern. This is not large, holding but a few^ ounces, and ducts open from this into the tissue of the gland. Following these ducts they will be found to divide into smaller branches which eventually end in little groups of cavities, the alveoli or ultimate follicles. These alveoli are in groups which m'5}- be likened to a small bunch of grapes. They Longitudinal section of a quarter of an udder. Cornell Experiment Station. The Secretion of Milk. 1? are lined by epithelial cells which derive their nourish- ment from little blood vessels surrounding them. They vary in size from one two hundred and fiftieth to one one hundredth of an inch in length and from one thirteen hundredth to one eight hundredth of a inch in diameter. The blood leaves the heart through the posterior artery which divides in the region of the hips, where it again divides into two arteries, the common illiacs, and again into two more arteries from which, after it has divided into many small capillary arteries, the cell tissue in the alveoli is fed. 12. Mills Veins. The cells use such portion of the blood as they need, and capillary veins begin to gather the venous blood into ever enlarging veins, until it is collected in a system of large veins just under the skin and surrounding the upper part of the udder much like a rope tied around it. From this surrounding vein or rather group of veins, for according to Bitting, there are 14 to 17 of them, large v^eins run from the fore part and posterior part of the udder back to the heart. These are the so-called milk veins. They do not contain milk, but are an indication of the milk-making capacity of the udder, as they indicate the quantity of blood used in the gland. If there hap- pens to be pressure on the anterior veins the blood may return to the heart by way of the posterior veins, and it is possible to have a large milker with small visible milk veins, but this is not likely, and it probably never occurs that an animal having large milk veins is a poor milker. The veins run forward, are often very tortuous and may branch several times and enter the chest wall through •openings, which are termed milk w-ells, and are some- times large enough to insert the end of the finger. ho •rj ;". (rt 91 (/> x: H C •n u. -1 X! UJ -a c c C o 0) u a; (I) is Qi 0) o bo c •n o ■*-* o CQ X) , >t- ft o ^ -< o F "^ o c fc > o en JZ C rtJ — • bo £ JZ 03 The Secretion of Milk. 1^ 13. Quality of Udder. Many udders consist largely of fibrous tissue and are termed "fleshy." Such an udder does not contract upon milking as will an udder composed more largely of glandular tissue. Some udders can be so milked out that they very largely disappear. An udder of a young animal may be deceiving as it is held firmly to the abdominal walls. In heifer calves on the sides, just above and in front of the flanks, may be found cords which later help to support the udder, and the size and strength of these cords is said to be an indication of the udder capacity of the animal in the future. In old cows which have been heavy milkers, the udder, on account of the heavy weight of milk it has carried, may be drawn partially away from the abdominal walls and be termed, a pendant udder. 14. Form of Udder. There is a natural tendency in cows for the rear quarters of the udder to develop much more than the Outline of square, well developed, udder. Pen drawing of a dissected udder and milk veins as seen from above. Drawn from original photo- graph, by Dr. A. W. Bitting. Shown in Twelfth Report of the Indiana Experiment Station. The Secretion of Milk. 21 fore quarters. The wise dairyman tries to develop the fore quarters, encouraging them to develop well forward, making what is termed a square udder. The teats should Outline of udder lacking in fore-quarter development. not be too prominent, for if the udder is cut up between the teats it is at the expense of glandular tissue. A Outline of a funnel-shaped udder funnel-shaped udder is one in which the teats are very prominent and the quarters of the udder small, so that Outline showing cut-up udder. The ideal udder would be filled out along the dotted line. Udder and milk veins of Johanna De Kol 2d, Holstein Friesian cow, owned by Gillett & Son, Rosendale, Wis. She gave 17,000 pounds of milk containing 644 pounds of butter fat in her four year old form. The Secretion- of Milk. O'A. the udder is shaped Hke a funnel. The teats should be set well apart and be large enough to grasp well with the hand. 15. Tlieory of Milk Secretion. The theory of the secretion of milk held by most authorities is that the cells in the alveoli are gradually built up between milkings. At the time of milking the agitation causes these cells to break down into milk. Udder cut-up between the halves. The reason put forward for this theory is that when an udder is cut open very little milk is found. If one has observed a nursing calf, lamb or kitten, considerable agitation of the udder was apparent. It has been shown by Professor Well that it is very necessary to agitate the udder in order to get all of the milk, that some milkers milk their cows apparently dry, but immediate subsequent agitation of the udder v/ill 24c Elements of Dairying. bring down considerable milk. He estimates that if the million cows in Wisconsin average as the cows with which he has experimented, with butter fat at 20 cents per pound, the value of the milk thus secured would be worth six millions of dollars. On the same basis with the 800,000 milch cows in Ohio, the annual income could be increased by $4,500,000. The method of manipulation employed by Professor Woll was first suggested by a Swede by the name of Helgelund. Abnormal-shaped udder. 16. Milk a Secretion. The milk is a distinct substance manufactured in the cells of the udder. It is not strained from the blood. Milk fat, as will be shown later, is different from beef fat. and milk sugar is found nowhere else in nature — it is a sugar peculiar to milk. The proteids of milk are also different from the proteids of the bod;-. The Secretion of Milk. 25 As soon as broken up into milk, the secretion finds its way down the milk ducts into the milk cistern and teat. Professor John H. Shepperd, while at the University of Wisconsin, conducted some experiments in the order of milking the teats, and in competing with a calf for the quantity of milk obtained. The calf was weighed before and after milking, and manipulated one side of the udder while the regular milker managed the other side. The next milking they would change sides, etc., to get com- plete checks. It is interesting to note that the calf was not superior to the man in the contest. Some milkers are, however, superior to others. By looking over the milking records at the University of Wisconsin, it was possible to pick out the cows milked by a certain milker, for he could (or rather did) invariably get more and richer milk from the same cows than when the cows were milked by other men. It was a noticeable fact that this herd of cows always gave less milk on Sunday than other days of the week, probably because the milkers were in more of a hurry that day and did not do their work as thoroughly. 17. Selection of a Cotv. It has been observed that the milk is made from the blood. In selecting a cow it should be remembered that blood is made from food and the cow should have a large chemical laboratory in her make-up for the diges- tion of food. There should be a good heart girth also, for the heart has to pump immense quantities of blood and the lungs are called upon to purify this blood. The nervous system also has a part to play for a large nerve branches ofT from the last dorsal vertebra and goes into the udder to control operations there. A prominent 26 Elements of Dairying. backbone and long tail indicate a good nervous develop- ment. The animal should not be tied together with thick beefy flanks, but should have plenty of room for the location of an udder and should have a distinct ten- dency not to put the food on her frame in the form of flesh, but to turn it into milk. CHAPTER IIL Water ajst> Solids of Mit.k. 18. Composition of Milk. Milk contains all the food elements necessary for ihe development of the young animal. Not only do these food elements vary in their percentages in the milk of any one species, but the variations are still greater among different species. The relative amount of devel- opment of the animal at birth produces different require- ments as to food. At first thought it may seem easy to give a statement concerning the composition of average cowl's milk, and this we will attempt to do, but as we study the subject it will be found that many factors come into play so that it is very difficult to determine just what is average milk. The following diagram will express to the eye in a general way the composition of what we may be pleased to call average milk. Water 57% For the water 0/ the bodtf (Ash .7% Foy Bone MilK 6oi;ci5i*)7o Solids noi Fat 7./%' /Albumen74 [Hair fod ZPI% ,5ugar J2 jHoo|5 IHorn For Heat and Fat But milk grows richer in solids as the period of lactation advances. Certain breeds of cattle give richer 27 28 Elements of Dairying. milk than others, and whole herds of cattle may give milk quite different in composition from other whole herds of the same breed. With these facts in mind we will study some of the variations. 19. Average Milk. It has been thought that the reports of tests and analyses of milk from a great many cheese and butter factories would give a fair average. Dr. Babcock secured reports from dairy students in Wisconsin dis- tributed over a large . territory upon which he based some conclusions, and Dr. VanSlyke, in New York, made careful and extensive analyses of milk in cheese factories and arrived at about the same conclusions as Dr. Babcock. There are, however^ localities where the stock has been crossed largely with Jersey blood where the results are too low, and again reports come from certain sections of Europe that are lower than the results of Drs. Babcock and VanSlyke. Dr. VanSlyke gives the following averages of cheese factory milk from the results of three years' w'ork. It is customary for the cows to come fresh in the spring and the milk to be carried to the cheese factory for six or seven months. It will be seen that the relation between water and solids varies from month to month. Table showing relation between water and solids in New^ York cheese factory milk : Per Cent. Per Cent. Month. Water. Solids. May ^7.U 12.5fi Tune 87.31 12.69 July 87.52 12.48 August 87.37 12.63 September 87.00 13.00 October 86.55 13.45 Water and Solids of Milk. 29 . Dr. VanSlyke calls attention to the fact that in July the lower solids are due to a drouth. so. Effect of Leiig^th of Lactation Period. The preceding table is, it will be seen, cheese factory milk. Dr. VanSlyke has taken a herd of fifty cows calv- ing in different months of the year and arranged aver- ages of the months in lactation with results quite different from the cheese factory milk as follows : Averages according to months in lactation of fifty cows : Month in Per Cent. Per Gent. Lactation. Water. Solids. 1 86.00 14.00 2 86.50 13.50 3 86.53 13.47 4 86.36 13.64 5 86.25 13.75 6 86.00 14.00 7 85.82 14.18 8 85.67 14.83 9 85.54 14.46 10 85.17 14.83 A person observing this second table, if he did not have the cheese factory averages before him, might con- clude that the average given in our diagram is entirely out of the way, 21. Effect of Breed. At the Geneva Experiment Station a breed test was conducted for several years. There were three to seven cows in each herd and the test ran from six to seven years. Other animals in the different breeds would probably have given somewhat different results from those ob- tained, but comparing these results with many other analyses we conclude that the figures are typical of the breeds. 30 Elements of Dairying. They are as follows : EFFECTS OF BREED ON COMPOSITION OF MILK. Breed. Per Cent. Water. Per Cent. Solids. Holstein 88.20 11.80 Ayrshire 87.25 12.75 Shorthorn 85.70 14.30 Devon 85.50 14.50 Guernsey 85.10 14.90 Jersey 84.60 15.40 The lowest testing and highest testing animals in the six breeds would make the difference still more marked. 22. L.eg'al Standards. It was formerly very difBcult to convict a man of adulterating milk for the reason that if he was really seen to water the milk it was still more difficult for the witness to follow it until delivered and be able to swear that the milk delivered was really the milk seen to be watered. Most states now have laws establishing legal standards for milk which state that a chemist's analysis shall stand for evidence in court. Some of these laws establish a standard for total solids. The Ohio law, for instance, requires twelve per cent, of total solids excepting in May and June, when it may be as low as eleven and a half per cent. This latter clause probably grew out of the fact that cheese factory milk tested low in these months. If the table showing efifect of period of lactation be examined again, it will be seen that the milk grows poorer until about the third month and from that time on grows richer again, follow- ing the abundance of milk flow, the solids being least at the time of greatest flow. The plan on w^hich the cheese factories operated was to have the cows come fresh in March and April and the flush of milk w^ould come in Mav and June. But factories are now operated the year Water and Solids of Milk. 31 round and milk in factories is coming to be paid for by test, while the large amount of milk sold for consump- tion is sold the year round. THe eleven and a half per cent, clause is evidently unjust. It has been decided many times in court that milk testing below a legal standard, though given that way by the cow. can be considered adulterated. In the eyes of the law, it does not matter whether the excessive water was put into the milk by a man or not. CHAPTER IV. Milk Fat. 28. Clieinica,! Composition. Milk fat is a mixture of a number of compounds and is made up of carbon 75%, hydrogen 13%, and oxygen 12%. The substances in the mixture are palmatin, olein, myristin, butyrin, laurin, caproin, stearin, dioxystearin. capryHn, and caprin. Palmatin melts at 144° F. and myristin at 129°, while olein and butryin are liquid at ordinary tempera- tures. Together they form a mixture in the form of milk fat that melts at 87° to 90° F. The proportions vary somewhat so that the melting point of the milk fat varies, as for instance, the fat in the milk of stripper cows has a higher melting point than normal. Oil meal and gluten meal fed to cows will lower the melting point, while cotton seed meal will raise it. Butter fat is the glycerides of the fatty acids corre- sponding to the above named fats. That is, glycerine 12.5% unites with 87.5% of the fatty acids to make the fats named. 24. Saponification. If the fat is boiled with an alkali the latter takes the place of the glycerine and makes a soap. If now the soap be boiled with an acid, the acid added will unite with the alkali of the soap and set the fatty acids free. These fatty acids appear to the eye to be fat. The Short milk test, which was invented at the Wisconsin Experiment 32 Milk Fat. 33 Station b> Chemist F. G. Short, now associate editor of Hoard's Dairyman, depended upon these reactions. A sample, 20 c.c. of milk, was measured into the test bottle ; then 10 c.c. of a potash solution was added and the mix- ture boiled for two or three hours, when the milk fat was turned to soap. Then 10 c.c. of a mixture of acetic and sulphuric acids was added and boiled for two hours longer. The fatty acids as they were liberated from the soap would collect in the neck of the bottle. Later when Dr. Babcock invented his method of testing milk, he used the Short test bottle and made his pipette 17.6 c.c. to correspond to the scale on the Short test bottle which included a volume of two cubic centi- meters. 25. Difference Bet^veeii Butter Fat and Oleo. The fatty acids of butter fat are a mixure, the same as the fat is a mixture of a number of fats. Some of these fatty acids are volatile, and here is a distinguish- ing difference between butter fat and oleo. The Reichert- Wollny test is based upon this fact. Five grams of the fat in question is weighed into a flask. A potash solution is added and the mixture boiled until the fat is turned to soap. Then sulphuric acid is added and the Hask attached to a still. It is then gently distilled so that 110 c.c. of distillate goes over in thirty minutes. The volatile fatty acids are driven over in the distillate, and when this is titrated w^ith a standard alkali solution, the amount of volatile acid driven over can be determined. If the fat in question was butter fat it would require tw^enty to thirty-five c.c. of the deci- normal plkali used to neutralize the acid in the distillate, but if o^eo, one or two c.c. would be sufficient. If it 34 Elements of Dairying. was a mixture of oleo and butter fat, an amount between that of oleo and butter fat would be required. The amount of volatile fatty acids in butter fat vary somewhat. Fall pastures and stripper cows have the effect of decreasing them in the milk. 26. Tests for Oleo. It is a rather difficult task to distinguish between oleo and butter fat on the market. Oleo will not get rancid like butter fat because of the lack of these lighter fats. If oleo be melted in a spoon over a gas jet it will simply melt down quietly, while butter will froth. 27. Color of Mills:. The color of milk is called lactochrome^ meaning simply milk color. We do not know just what it is. It is more evident in the milk of fresh cows on succulent feed or good pasture. It is also more noticeable in the milk of G\iernsey and Jersey cows. It is in the butter fat as is quite evident by watching" a centrifugal cream separator, when it will be seen that the cream has a yellowish color, while the skim milk is quite white. In making butter and cheese, artificial col- oring matter is added to make up the deficiency of color at certain times of the year. The color thus added is- either annato — made from the coating of annato seed or an analine color. The cheese color is made by boiling the seed in lye and colors the casein, but butter color has the color dissolved in oil and will therefore be incorporated with the butter fat, but will not mix with the butter milk. 28. Fat Globules. Fat will not dissolve in the water of the milk, but is in emulsion. It is broken up into minute globules that Milk Fat. 35 vary in size from 1-1500 to 1-40,000 of an inch in diame- ter ; that is, it would take 40,000 of the smallest globules placed side by side to make a row an inch long. 20. Numbers in. a. Drop. There are 150,000,000 of them in a single drop of milk and it would require 30,000,000,000 to weigh a single grain. It was estimated that the cows in the herd at Cornell University manufactured on the average 38,210,000 of them per second. 30. How Counted. The reader may wonder how it is possible to count such a large number in so small an amount of milk ; for counting two per second, and working steadily 12 hours per day, it would take 180 days ; or how they can be picked out of the drop of milk and laid aside one by one so that they will not be counted a second time? It is done as follows in a very few minutes : A small glass tube, such as can be procured at the drug store, is heated in a gas lamp and two men run in opposie directions with the ends. This draws the tube out into a fine hair- like tube. The milk in question is then diluted fifty times with water, so that there will be only one globule where formerly there were fifty. The diluted milk is drawn into these little tubes and the ends plugged with vaseline. The tubes are put under a microscope and there in the tubes are seen the little fat globules, ten or a dozen or twenty. By means of a micrometer in the microscope the length and diameter of the tubes can be measured and then computed into volume, and then the volume is multiplied to that of a drop, and we thus know how many globules there are in a drop. 56 Elements of Dairying. ^t. Relative Size of Globules. We have given the size of globules with a sugges- tion that they are not all of the same size. They are larger in the milk of some breeds of cows, and are much more numerous and smaller in the milk of strippers than in that of fresh cows. Succulent food also decreases the size as well as increases the number. The globules are larger in the strippings than in the fore milk. While some breeds of cows as the Jerseys and Guernseys give rich milk and have, comparatively speaking, large globules, richness of milk does not necessarily control the size of the globules, for the factors mentioned above, as period of lactation for instance, may change this. The large globules have 67 times greater bulk than the smaller ones, and are 250 to 300 times greater in weight. This fact has an important bearing on the creaming of milk as will be explained later. Perhaps the average diameter of milk fat globules is 1-10,000 of an inch. The following sizes of fat glob- ules according to breeds are given by the Geneva, N. Y._, Experiment Station : Holstein •*• 12090 Ayrshire ^ 12450 Devon •'• 10370 Guernsey — 9350 Jersey — 9630 Milk Fat. 37 33. Per Cent, of Fat in Milk. The per cent, of fat in milk means the number of pounds of fat in one hundred pounds of milk. The fat is the most variable constituent of the milk and it would be difficult to make an exact statement of what the aver- age fat test is in cow's milk. Dr. Babcock finds that it is 3.7% when Wisconsin cheese factory and creamery milk is concerned, and Dr. VanSlyke finds that New York conditions give about the same results. The percentage usually increases with the length of the period of lactation, with possibly a slight drop the second or third month when the flow of milk is greatest. The fifty animals at the Geneva Experiment Station which were averaged according to months of lactation for solids were also averaged for butter fat as follows : Month of Average Lactation. Per Cent. Fat 1 4.54 2 4.38 3 4.28 4 4.39 5 4.38 6 4.53 7 4.56 8 4.66 9 4.79 10 5.00 33. Effect of Breed. Breed also affects the fat content of the milk. Hol- steins are noted for the large quantity as well as thin milk that they give, while Jerseys give less but richer milk. 38 Elements of Dairying. In the Geneva breed test previously mentioned the average, low, and high tests for each breed are given : GENEVA STATION BREED TEST. AVERAGE PER CENT. OF FATS. Breed. Average. Low. High. Holstein .3.36 2.88 3.86 Ayrshire 3.60 3.20 4.24 Devon 4.60 4.30 5.23 Guernsey 5. .30 4.51 6.13 Jersey 5.60 4.06 6.09 34. Strippiiigrs Compared Witli Fore Milk. It has been stated that the elaboration of milk occurs in the epithelial cells of the alveoli. The fat globules are formed there and the cell walls breaking down, they are discharged into the cavity of the alveoli, and find their way down the milk ducts into the teat. But as they are solid bodies and rub along the w^alls of the milk ducts, they do not travel as fast as the milk serum (some authorities think they are not elaborated as rap- idly) and the result is that the last of the milk or the strippings, as it is called, is much richer in fat than the iore milk. Successive samples taken during a milking have l3een shown to test .9%, 2.6%, 5.35% and 9.% fat. The thoroughness then with which the udder is emptied, affects the fat content of the milk given. While it is not always true, it is usually the case that short periods iDetween milkings produce richer milk than long periods. Attention has already been called (15) to the fact that some milkers can get more and richer milk than others from the same cows. This may be due to method of milking and agitating the udder, and it is possible that the cows like certain milkers better and give their milk ■down better. Milk Fat. 39 35. Effect of Excitement of Cow. Professor Woll has called attention to the fact that sickness with fever or excitement will cause smaller fat globules, and perhaps the amount secreted may be affected. We give a few instances that have come to our ob- servation : It was the privilege of the author to operate the Babcock milk test the first time that it was exhibited outside of Madison. This was at the Portage and Bara- boo Fairs, September, 1890. The Hon. John M. True was president of the Baraboo Fair and lived on a farm adjoining the fair grounds. He had a grade Jersey cow called Daisy which he brought onto the grounds to be tested. She was milked at six in the evening after the day's excitement on the grounds, and again in the morn- ing at home, under normal conditions, at six o'clock, with the following results : DAISY TRUE AT BARABOO FAIR. Time Pounds Per Cent. Pounds Milked. Milk. Fat. Fat. Six p. m 21.75 6.5 1.41 Six a. m 19.38 5.4 1.05 Totals 41.13 2.46 It will be observed that after the day's excitement she gave more and richer milk than in the morning after quieter conditions. The record for the day was an ex- ceptionally good one and if kept up for a week would make 17.22 pounds of fat, which would probably produce twenty pounds of butter. It was therefore decided to make a week's test. The results as compared with tlie day at the fair were : Miik. Per cent. Pounds' Pounds per day. Fat. Fat per day. Poorest day 38.5 3.99 1.81 Best day 44.5 5.16 2.19 The Hon. John M. True's cow, Daisy, shown at the Baraboo, Wis. Fair, 1890. Milk Fat. 41 The total fat for the week was 13.81 pounds and the best test and best day's fat did not come up to the test of the day at the fair. But she did well enough to have her photograph taken, and it was desirable to have the picture taken with the udder full, so instead of milking at six in the morning as usual, the picture was taken at nine when the light was sufficient, and the animal much to her dislike, was separated from the other cows. Then came the milking and she gave 28.25 pounds of milk testing 6.33% fat, the highest record made by her. Elaborating a little over a pound and a half of milk per hour during the previous week, it was wholly unexpected for her to give eight pounds extra for three hours extra time, and the butter fat was still more of a surprise. 36. EfiEect on Pat of SUowins" at Fairs. We also give another instance of excitement, work- ing in this case to the detriment of the results. Two Holstein-Friesian cows belonging to Gillett & Son of Rosendale, Wisconsin, were tested first at home, again the next week at the Fond du Lac County Fair, third at the State Fair at Milwaukee, and following that went to the Indiana State Fair, and the fifth w^eek tests were reported from the Illinois State Fair : The results were as follows : ftijanetta. Where Pounds Per Cent. Pounds Tested. Milk. Fat. Fat. At home 60-38 2.52 1.52 ^ 59.94 2.83 1.70 At Fon du Lac ^^-25 2 73 1.56 °" "^^^ ^^"^-53.80 3.10 1.67 At Milwaukee.. I J2 31^ }]? 33.00 3.37 Lll At Illinois State Fair 39.00 1.84 .72 26.00 1.10 .12 Duchess of Springvale Fourth, Pounds Per Cent. Pounds Milk. Fat. Fat. 34.63 2.75 M 33.01 2.90 .96 33.00 3.16 1.04 33.60 3.33 1.13 32.50 3.04 .99 42 Elements of Dairying. The trip to Indiana was very hard on the cows and they were said to have arrived at the IlHnois Fair much exhausted. An interesting question arises ; did the milkers get all of the milk elaborated? If not^ the short- age of milk and butter fat is easily explained by saying that the strippings were left in the udders. The milkers, however, seemed to think that the cows did not elaborate any more than was drawn from the udder. 37. Hig-liest Testing Normal Milk. After thirteen years experience with the Babcock test, in which time we have tested thousanas of samples of milk, the richest sample in butter fat, of which we were sure that it was a fair sample of the whole milking, tested 10.7% fat. The cow did not give this amount regularly, but dropped at the next milking. In but a few cases have we found milk testing nine per cent., and it is a rare thing for a cow to average seven per cent. The subject of testing cows will be discussed in a later chapter of this book. CHAPTER V* Milk Solids jsot Wajt, 38. Ash. The ash of the milk is the mineral matter that is left after burning off the organic matter. It contains all of the mineral matter necessary to build up the bony frame work of the growing young animal. The milk is a very complex substance and it is very difficult to determine just how all of the mineral elements are combined. The following chemical elements go to make up the ash : Calcium, sodium, potassium, magne- sium, iron, phosphorous and chlorine. Calcium and potassium phosphates are present, and the former is supposed to be combined with the casein. Some of the ash is soluble and part is in little particles held in suspen- sion, for it can be filtered out in a porcelain filter or thrown out in a separator bowl, which would not be true if it were ah in solution. The ash st:ems to be quite uniformally present in cow's milk to the extent of about .7%. If we had as much data about the ash as about the butter fat we might not be able to speak as positively about it. Rennet, the ferment from the calf's stomach, which is used in making cheese, will not coagulate the milk if the soluble calcium (lime) salts are absent. 39. Proteine Componntls. The proteine compounds are those which contain nitrogen, and a little sulphur and phosphorous. It is 43 44 Elements of Dairying. found in the form of two substances ; caseine, the cheese part, and albumen. 40. Caseiiie. The caseine consists of carbon 53%, oxygen 22.7%, hydrogen 7%, nitrogen 15.7%, phosphorus .85%, and sulphur .75%. It is not in solution but is in a colloidal state much like starch held in hot water. This is proved by filtering it out of the milk by means of a porcelain fil- ter, and by throwing it out by whorling the milk for a long time in separator bowl. Dr. Babcock discovered this latter method and separated the caseine that he studied, in a Danish Weston separator bowl. The sub- stance deposited on the walls of the bowl 'was a milky slime. When dried on glass it became transparent with a flourescent appearance. The results of one of Dr. Babcock's experiments was as follows : Per Cent. Per Cent. Per Cent. Per Gent. Ash in Dry Skim milk diluted with Solids. Nitrogen. Ash. Substance. equal water 4.25 0.24 .396 9.82 Liquid after 3 hours =1.53 proteine whorling 3.25 0.12 .283 Total substance removed in3hours 1.00 0.12 .113 8.04 This table shows that a substance containing nitro- gen was thrown out and with it some ash, and Dr. Babcock concluded that the ash or at least a portion of it was not in combination with the caseine. 41. Caseine and Albumen, Hotv Separated. Caseine is coagulated by rennet and dilute acids, but not by ordinary heat. Caseine is precipitated by heat of 265° F., which is secured only under pressure, while the albumen is coagulated by heat and not by rennet or acids. Milk Solids not Fat. 45 If after coagulating milk with either rennet or dilute acids the whey is heated to 180° F., a white precipitate (which is the coagulated albumen) is thrown down. The proteine substances, both caseine and albumen, increase in the milk with the period of lactation. The following table compiled by Dr. VanSlyke shows this in- crease : Table showing effect of period of lactation upon the per cent, of caseine and albumen in milk : Month of Per Gent. Per Gent. Per Gent. ^actation. Proteine. Gaseine. Albumen, 1 3.00 2.45 .55 2 2.96 2.45 .51 3 3.08 2.51 .57 4 3.10 2.48 .62 5 3.10 2.55 .55 6 3.75 2.65 .92 7 3.66 2.91 .75 8 3.77 3.00 .77 9 4.03 3.15 .88 10 5.05 3.66 1.39 There is usually three and a half times as much caseine as albumen in cow's milk. 42. Milk Su^ar. Milk sugar, or lactose, forms one-third of the solids of the milk, and more than half of the solids of separator skim milk. It is less sweet than beet or cane sugar, and is obtained commercially from the whey at cheese fac- tories. 43. Sugrar, Ho^v Obtained. An easy experiment can be made by first coagu- lating a quart of skim milk with rennet or acid. Strain out the curd and then heat to the boiling point and the albumen will be precipitated. Let this settle and decant the clear liquid or filter it and then boil the clear liquid to dryness. The milk sugar and ash will be left behind 46 Elements of Dairying. in the form of a white powder. Milk sugar has not been studied as much as the fat and caseine, but it is reported to vary from three to six per cent., with an average of five per cent. It is a carbohydrate and is valuable in whey or skim milk for feeding to calves or pigs. CHAPTER VI* THE PHYSICAL PROPERTIES OF ]SHLK. 44. Physical Condition of Milk. We have seen in the preceding chapters that milk consists largely of water in which are dissolved the sugar, most of the ash and the albumen, while the caseine is held in a colloidal state and some of the ash in suspen- sion. This forms the milk serum (same dS separator skim milk) in w^hich the fat is held in emulsion. 45. Specific Gravity. If we take a barrel that will just hold 1000 pounds of water at a temperature of 60° F. and fiU it with milk serum, we will find that the barrel will hold approxi- mately 1036 pounds, and we say that the skim milk, or milk serum, has a specific gravity of 1.036. If we fill it with butter fat at 60° F. less than 1000 pounds or 930 pounds will fill it, and it has a sp. g. of .93. The fat in whole milk being much lighter than the other solids reduces the specific gravity to perhaps 1.032. The lowest specific gravity of pure milk that has been found w^as 1.029. If the temperature of the substance in the barrel be raised, for each degree approximately one-tenth of a pound will run over the top, caused by the expansion. If the temperature be lowered, the milk will contract so that for each degree, approximately one-tenth of a pound more may be put into the barrel. 47 48 Elements of Dairying. 46. Lactometer. An instrument known as the lactometer, being a weighted glass bulb with a long stem at the top upon w^hich is written a scale, just floats in water of 60° F. to the zero mark. In milk of 1.032 sp. g. it is bouyed up until it reaches the corresponding point on the scale. By means of the lactometer the specific gravity of milks can be obtained. Both butter fat and water when added to milk reduce the specific gravity. When the right amount of water is added to sepa- rator skim milk, the lactometer which does not distin- guish the difi:*erence between fat and water, but simply shows that it is lighter, might lead us to believe that the milk is pure when the facts are, that it is both skimmed and watered. If we call the Babcock test to our aid it will tell us whether the fat is there, and by using both instruments we can readily determine the adulteration. 47. Creaiiiiiig- of Milk. The fat globules, being lighter than the surrounding serum, have a tendency to rise by the action of the force of gravity. If we take a glass cylinder or bottle, and fill it with soap solution and shake it to incorporate air, and then set it down, the air bubbles will rise to the top forming a lather (or cream). It will be observed that the large bubbles rise much faster than the smaller ones. The air in the bubbles is all the same kind of air. In like manner the large fat globules rise faster than the small ones. It is not because the fat in the large globules is any different than in the small ones. i\ctual analyses of the fats have shown them to be identical in every way. 48. Viscosity. The milk serum is slightly viscous, or sticky, like molasses, and the colder it is the more viscous it be- The Physical Properties of Milk. 49 comes. Skim milk at the freezing point may become so viscous that it can be whipped up into a froth. This stickiness of the milk serum holds the fat globules back like a brake, or they would quickly form a layer of pure fat on the top. The large fat globules have less surface than the small ones in proportion to their cubical couj tents, and consequently the difference between upward gravity pressure and the brake pressure is greatest in the large globules:. 49. Lility of Separators. The life of a machine depends, of course, upon the construction of the machine, and likewise upon the care it receives. Dirt and poor oil, and harsh handling will wear out a machine in short order when it might other- wise last a long tim_e. The expense of a machine is not so much in the cost of material, as in the skilled labor in its manufacture. The bowl has to be turned, tinned, and carefuUv balanced. The Physical Properties of Milk. 55 58. Theory of Clmrningf. A theory was formerly current that the fat globule was enveloped in a membrane which was broken in churning*, but no one has ever seen such a membrane, and many people have seen under the microscope the soft fat globules running together. If the temperature is high enough that the fat is soft and pasty, the "butter comes" quickly. On the other hand if the temperature is below 50° F., the butter will not churn. Our grand- mothers used to drop a red hot horseshoe into the cream to drive out the witches and the butter would come — simply because the fat was warmed up enough to make it soft enough to stick together. 59. Varieties of Clinriis. A great many churns have been patented and placed upon the market, with the claim that they will bring butter in five minutes. Among these churns are a num- ber of machines going under the enticing name of ''but- ter separator," of similar construction, in which a turbine wheel inserted in a vessel of wood, stone or metal draws a current of air down a hollow shaft into the cream. It is claimed that the air oxidizes and does many things unknown to chemists, eventually sepa- rating the butter in five minutes. When the air shaft is closed with a cork the device works just as well without the air. and the time for churning increases as the tem- perature of the cream or milk is lowered. Of the many churns invented none is better or more ef^cient than the common box or barrel churn. 60. Effect of Teinperatiire Ipon Cliiiriiinjsj:. When the temperature of the cream is high enough to make the butter come in five minutes, the fat is so 50 Elements of Dairying. soft that the butter is soft and the grain becomes greasy and salvy in handhng, salting and working. Quick churning is, therefore, at the expense of the quahty of the butter. Cream churns best — that is, the most exhaustively and makes the best grained butter, when the cream is rich in fat (35%) and the tempera- ture low (but little above 50° F.). When cream is thin, the large fat globules strike and accumulate into gran- ules before the smaller globules have a chance to come into contact with other globules. The result is that there is not only a large amount of butter milk in which to lose fat, but it is richer in fat. 61. Advantage of Rich. Cream, By having the cream thick, the globules of fat are brought so close together that the small globules must strike other globules. By churning at a low tempera- ture when the fat is harder, the time of churning is ex- tended, giving the small globules a longer time in which to get a chance to adhere. The result is that there is less butter milk in which to lose fat, and the fat test of it is low. If the cream is very thin, it will be found neces- sary to raise the temperature to such a point, that the globules will be soft enough that when they do strike they will adhere. It is sometimes found necessary to raise the temperature of thin cream to 65° F. in order to get the butter to come at all. 62. Clinrning' Cream From Strippers' Milk. In case of stripper cows when the fats are harder or where cove's have been fed on cotton seed meal, thus hardening the fat, it is necessary to raise the churning temperature. The Physical Properties of AIilk. 57 63. lieasoii Cream Tlticlceiisi Before Breaking,'. Cream will thicken in the churn just before the but- ter comes. If the cream is rich in fat, 40% or above, it will become so thick that it will not drop in the churn, and it is necessary to thin it up with water in order to continue churning. The fat globules that at first had room enough to pass each other, begin to stick together, and their rough edges stick out against each other so that they cannot pass, and the whole mass of them being unable to move past each other makes the cream a mass that will not drop in the churn. The addition of water gives them a chance to pass. We may conclude from these conditions that cream should be about 35% fat for best results in churning. Richer cream will stick in the churn, and thinner cream gives more butter milk in which to lose fat^ and the per- centages of fat are higher, as borne out by experiment. 64. Viscosity AflEected by Condition of Pat. We have seen that before the cream oreaks into butter in the churn, it becomes thicker, and that this is because of the grouping of the fat globules. Cream raised by the gravity process appears thicker, or more viscous, than separator cream of the same fat content. Cream pasteurized at temperatures above 140° seem thinner than before pasteurization, and milk pas- teurized above 140° F. sometimes fails to show a cream line. The microscope has revealed the cause. In the gravity creaming, and in milk that stands, the fat globules at first separated from each other begin to collect in little groups, and the ferment galactase probably clots some of the proteine around them, binding them together. f^-'T < IT ^ '.'^ «o' •o - '^IilU. Dr. W. H. Conn says that milk has a germicidal property. There is a preliminary period of the decline of the number of bacteria, this period varying from three to forty hours according to the temperature, and also possibly with the cows. At 70°, this period is six to nine hours. At 50°, it is forty hours. 82. Growth of Bsicteria. When the germicidal property of the milk is ex- hausted the germs increase in numbers, but the rate of increase is reduced by low temperature. Rate of increase of single germ : 2 Hours. 3 Hours. 4 Hours. At 54° 4 6 8 At 97° 23 60 215 Bacteria found in milk may be classified as neutral, lactic, putrefactive and pathogenic. In milk are found numerous species of bacteria that increase in numbers, but do not seem to change the char- acter of the milk any. The lactic bacteria are those that have the property of souring milk, of which about 200 species have been observed. 83. Acidity of Milk. The caseine of milk has an acid reaction so that cow's milk freshly drawn from the udder will show .10 to .15% of what is usually classed as lactic acid, though it is not such. The bacteria act on the milk sugar, breaking it 5 Hours. 6 Hours. 26 435 1830 3800 Contamination of AIilk. 7'6 up into lactic acid. When .3% acid has developed the milk begins to taste sour, and at .7 or .8 of a per cent., according to the temperature, it curdles. The bacteria go on forming more acid until about .9% is present, and it then inhibits their growth. The sugar of which there was 5% when the bacteria began to grow, has not all been used up. There is still about 4% left. Milk that has more than .7% acid is not commonly received at factories for butter and cheese making, nor by milk dealers for consumption. Lactic acid bacteria do not grow much below 45° F. Other more dangerous forms may grow below that temperature. 84. Putrefactive Bacteria. Under the head of putrefactive forms we may class those bacteria that produce gas, digest the proteine, pro- duce bad odors, and a few other peculiar kinds. Cheese makers are often bothered with pin holes developing in the curd and cheese. These holes are due to gas-forming bacteria, one form being Coli communis, which is found in barnyard filth. Another form, found in northern New York and Canada, causes rusty spots in cheese. Still another kind causes slimy milk and grows at low temperatures. This particular germ is surrounded with a gelatinous envelope, and when the bacteria become numerous enough they make the milk ropy or slimy. An odor resembling soft soap in milk has been traced to bacteria. It may be said that the putrefactive kinds of bacteria are usually associated with and arise from filthy conditions. 85. Patliosenic Bacteria. Many forms of disease are trated to definite species of bacteria. '''-i Elements of Dairying. Probably one hundred epidemics ot typhoid fever and diptheria have been definitely traced to the milk supply. Probably one hundred epidemics of typhoid fever have been carried by milk, the original source being a well or spring, the water of which was used to rinse the pails and cans in it, and the milk afterward being put into these vessels was inoculated. Lactic bacteria are likely present in very small num- bers in the milk soon after it is drawn from the udder, and if present will multiply very rapidly and crowd out other forms. Lactic acid bacteria are very desirable in butter making and certain forms of cheese making. Pure cultures of bacteria are now put upon the market on a large scale. Orin Douglas, and Kieth of Boston and Chr. Hansen's Laboratory at Little Falls, New York, each does a large business. 86. How to Combat Bacteria. Bacteria may be killed with poisons such as forma- lin, boric and salicylic acids, etc., but in milk these are very dangerous to the health of people using the milk, are prohibited by law, and their use in milk is to be condemmed. 87. Keep Bacteria Out. The best way to produce good milk is to prevent as far as possible the bacteria getting in. To this end the cows should be kept carded and clean, the stable should be well lighted and ventilated, hay should not be stored overhead if the floor is loose so that dirt may sift down. The stalls should be so constructed as to keep the cows out of filth. Contamination of Milk. 75 88. Milkers. The milkers should have clean hands and suits, and just before milking, the flanks and udders should be wiped with a clean damp rag to lay the dust so that it will not fall into the milk pail. A pail with a top so constructed as to keep out the falling dirt, and at the same time can be easily cleaned, is desirable. Then the milk should be taken out of the stable as fast as Star Milk Cooler. milked, and strained and cooled. The most effective cooler is the Star, with corrugated surfaces over which the milk flows while cold water flows on the inside, and the milk can be cooled to within one degree of the water. The Champion cooler, which is a conical vessel over the surface of which the milk flows, is also effective. Several sanitary dairies, one in Illinois, and others near New York City, which produce milk under such conditions as described above, packed milk in ice, sent it to New York where it was transferred to the refrigerator of an ocean liner, and then after seven days on the ocean, Champion Milk Cooler as used by a patron of the National Milk Condensary, Kent, Ohio. --'/V_-v, e:e it?S^ ^-SVl^i-f;^- • .V -• — PROGENY or A SINGLE GERM ® ilM TWELVE HOURS Diagram showing the effect of temperature on bacterial growth— Russell. Contamination of Milk. 77 at Havre, France, was put into a refrigerator car, and arrived at the Paris Exposition in excellent condition, and was kept several days there until used, in fact milk eighteen to twenty days old was as good as French milk twenty-four to forty-eight hours old. x-\ll tiits was done by keeping dirt and bacteria out of the milk as completely as possible. A few bacteria probably got into the milk, but keeping it cold, extended the length of the germicidal period, and afterv.ard kept the development of the few bacteria present in check. so. sterilization. But it IS mipossible to control a large milk supply as completely as just described, for farmers will be care- less, and will not go to the extent necessary to keep the germs out as completely as desirable. The only way to handle such milk is to 'cill the bac- teria. This can be done by heat. To sterilize milk, that is kill all of the bacteria in the milk, it will be neces- sary to heat the milk above the boiling point under pressure. Some bacteria go into the spore stage ; that is, go into a seed form, and these spores or seeds will stand high temperature, some k'nds even a boiling temperature. But it is not practical to. put milk under steam pressure, and if this were done the milk would have a disagreeable burnt taste, due to the changing of the albumen (which it will be remembered contains sulphur). It is evident that when people talk about sterilizing milk the}' do not understand wliat the sterilization of milk really involves. There is no sterilized milk on the market. They mean that milk is pasteurized. 90. Pasteurization. By heating milk to lower temperatures than the boiling point for some time, all vegative or growing 03 "O (U (U (tf -^ 3 03 (/) >- ^ be <" J;^ ^ •OT3 o '"'So Irt ^ O ? « « o « t« ^ _ «> c gjr 03 O ^ I- ^ o CO o (tf w „,-^ (U (J C C (tf o£ in (/) _ £^ - c-j= = o^ v o ^ in (U O in in O . T3 ^ o o C 3£ - ■^ o le. If the record of a cow is based on a single test, it will make considerable difference whether the high or low 86 Elements of Dairying. testing sample happens to be taken as the basis of calcu- lation. lOl. Professor Farrington's E^xpei-iineiits on Averages. Professor Farrington has for several years con- ducted careful tests of cows in the herds of patrons of the University creamery. Composite samples of all of the milk given in a year by the cows were tested once a week. Samples for single days (two milkings) were taken at different lengths of time apart, to determine, as com- pared with the record of samples of all the milk given by the cows, the accuracy of computing averages when testing and weighiug the milk once in seven, ten, fifteen or thirty days. i\veraging the results from seven of the most variable cows, the results were as follows : Once in seven days, gave 98 per cent, of the total' milk and 98 per cent, of the total butter fat. Once in ten days, gave 98 per cent, of the total milk and 99.4 per cent, of the total butter fat. Once in fifteen days, gave 97.6 per cent, of the total milk and 98.5 per cent, of the total butter fat. Once in thirty days, gave 96.4 per cent, of the total milk and 97 per cent, of the total butter fat. Richness of milk, or a large fiow of milk for a short time, will not necessarily make a cow a large producer of butter fat. 102. Milk Flow and Ricliness Combined. A combination of rich milk and a large persistent fiow are the factors making a large record, as is shown in the case of Dolly Bloom. The best cow is the one that makes the most butter fat in the year at the least cost. A cow must produce about 170 pounds of butter fat to pay the cost of keep- Testing Cows. 87 ing. A cow should give at least 250 pounds of fat per year to be really valuable. Below are given the records of some creamery cows as reported by Professor Farrington in Bulletin 75 of the Wisconsin Experiment Station : Table showing milk and fat yields of Wisconsin cows : Factory Value Cow Days Pounds Per Cent. Pounds. Value of Fat No. Age. Milked. Milk. Fat. Fat. Milk. Per Pound 25 6 365 7,887 3.95 312 $58.25 18.6 1 7 303 6,182 4.8 296 53.25 18 9 7 273 3,792 3.9 147 28.72 19.5 10 9 209 4,061 3.9 160 32.13 20 In the above table to make the facts still plainer the factory value of the butter fat is stated. Some of the cows came fresh in the fall, and winter butter fat brought higher prices, which explains the varying values of butter fat, which modify the results somewhat. Comparing cows Nos. 1 and 9 it is evident that the flow of milk should be large as well as persistent. 103. Value of Pedigree. As an illustration of the value of registered full blood cows over comm.on stock, a record of official tests of Guernsey cows in Wisconsin, 1898-99, published in the Wisconsin Experiment Station, Report XVII, is given below : Registry Pounds Milk. Pounds. Per Cent. Name. No. Age. in'l Year. Fat. Fat. Lilly Ella 7240 5 12282.68 782.16 6.42 Lilyita 7241 5 12812.73 710.58 5.69 Countess Bishop.. 7869 4 7387.3 452.23 6.42 Madam Trickesy.. 6519 6 7024.6 405.19 5.85 Lady Bishop 6518 7 6608.9 381.1 5.40 Pristoun 6570 7 6^^.^ 355.68 5.19 Nounon 6569 9 6338.0 351.7 5.51 yS Elements of Dairying. A 3-ear's record established in this way may have points for criticism, but is more valuable in estimating the value of an animal, than a test for a short period un- der pressure, as in the seven-day test. 104. Unusnal Test of Dncliess of Oriusby. An unusual test of the Holstein-Friesian cow Duchess of Ormsby (16004) was made under the author's direction. She was tested in January, 1899, giving 356.9 pounds of milk, averaging 5.41: per cent, fat, or 19.41 pounds of fat. Her best milking showed 18 pounds of milk, testing 6.3%. fat, and her poorest milking 19.7 pounds, testing 4.65% fat. This was phenomenal for a Holstein, and Professor Woll went to the farm the fol- lowing week, and secured samples which tested over 5% fat. Her milk flow increased, and on February 24 an- other seven-day test was started, in which she gave 387.1 pounds milk, but the average fat dropped to 4.29 per cent., a total of 16.61 pounds of fat. The milk flow con- tinued to kee]) up and on May 16 a third seven-day test was begvm, which resulted in 381.5 pounds of milk, aver- aging 3.67%o fat, or 14.02 pounds. We have no satisfactory explanation to offer for this peculiar and unusual variation in fat test. Attention has already been called (pp. 38-41) to some of the usual variations in fat test. 105. DiflEerence BetTreen Mean and Average. Sometimes patrons at creameries take samples from the milk of each of their cows to have them tested. The percentages will be added and the sum divided by the number of cows. The result quite often shows a higher percentage than the average weekly test and there is Testing Cows. 89 trouble ahead for the butter maker. The resuh so ob- tained is not an average, but an arithmetical mean. In securing an average, the weights of milk given by the cows must be taken into consideration^ as well as the fat tests. The following example will explain this. A man has two cows which give milk and test as follows : Pounds Per Cent. Pounds Milk. Fat. Fat. No. 1 50 3.0 1.50 No. 2 20 5.0 1.00 Total 70 2.50 The arithmetical mean is obtained by adding the percentages and dividing by 2, which gives 4 as the mean. The average is obtained by dividing 2.5 by 70 and multiplying by 100, which gives 3.57% as the average. CHAPTER X. MlAJRKET Milk 106. Value of 31111^ and Cream. "Milk and milk products have had a most important effect upon the dietary of civilized people. Among high class food products, few are more healthful than miilk when it is pure, and few food products contain greater possible dangers than when it is not pure. Many people restrict themselves in the use of milk under the impression that they are practicing economy. As a matter of fact one quart of milk containing five per cent, of butter fat has a food value equal to five-sixths of a pound of sirloin steak, to say nothing of the greater ease of serving or its greater healthfulness. A pint of cream, containing twenty per cent, of butter fat has a food value equal to five quarts of strawberries. This does not mean that one should be used to the exclusion of the other, but milk and cream are articles of diet that deserve a much greater use both from the standpoint of economy and healthfulness than are at present ac- corded them." — Dr. Thomas F. Hunt. 107. Ancient Metliods of Milk Delivery. With the advance of modern civilization the milk supply for purposes of consumption of our country is keeping step. In unprogressive cities of the East the milkman proves the purity of his milk by driving the cow up to the door to be milked, but the unsuspecting public does not know that the first customer who gets 90 Market Milk. 91 the fore milk gets skim milk, while the one who gets the stoppings gets cream. 108. Cans vs. Bottles. The milkman in our cities who delivers his milk from cans and measures the milk for each customer drives over the dusty streets tilling his measures with dirt as he goes. The glass bottle securely capped pre- vents this. While more expensive, it is claimed that the extra milk that has to be given in the other method for good measure, together with the milk that is slopped, will pay the cost of the bottles. Glass bottles may, however, be more unsanitary than the other method if the bottles are not properly washed by the milk dealer. Bottles come from homes of questionable cleanliness or from homes harboring dis- ease, which may be carried to other customers through the milk bottles. It is therefore necessary to thoroughly wash and sterilize the bottles. The washing is usually done with a brush revolving on a shaft, and then sterilized by placing the bottles in a chamber which is then filled with live steam. All utensils which are used in contact with the milk should be likewise sterilized. A new bottle washer used in large establishments takes the bottles placed in two rows in racks, a dozen bottles in a rack. They are first subjected to jets of hot salsoda solution, next to jets of hot rinsing water, and third to jets of hot steam, coming out of the other end of the machine washed and sterilized. 109. Millv Ticlcets. It is evident that milk tickets which are used many times may become dirty and so become conveyers of disease. Coupon tickets which are sold in strips, from 92 Elements of Dairying. which pint or quart squares can be aetached and de- stroyed after once using, are coming into favor. 110. Market Terms. Milk is sold under a number of different terms, such as pasteurized, aerated, certified, standardized, and modi- fied. Pasteurized milk has already been considered. 111. Aerated Milk. Aerated milk is milk that has been subjected in fine streams to the air. Among cheese and butter makers aeration is considered very essential, but experiments at a number of experiment stations have led to the uniform conclusion that the only value of aeration is in cooling the milk, which cooling very naturally retards bacterial growth. 112. Certified Milk. Certified milk is so called, because the producer has an arrangement with physicians to take samples for chemical and bacteriological analysis, and to inspect the cows, premises, etc., after which the physicians make a certified statement that all such provisions have been complied with, and that the milk is pure in every re- spect. 113. Standarilized Milk. Standardized milk is milk standardized to a certain per cent, of fat. Often milk producers guarantee to sell milk or cream of a certain standard per cent, of fat for a certain price. It is necessary in such cases to take out some skim milk, making a higher percentage of fat". It is clearly illegal to abstract any fat from whole milk and then sell it for anything else but skim milk. Market Milk. 93 114. Staiidardiziug' from Cream and Skim Milk. As an example of the method pursued, suppose we are standardizing milk to 5% butter fat. We have 332 pounds of milk testing -iA'/c fat, or it contains 13.846 pounds of fat, which divided by 5, the per cent, of fat re- quired, gives 2.TG9 and this multiplied by 100 gives 276.9 pounds of milk that it will make. We run the milk through the separator and obtain perhaps 45 pounds of cream. The amount of cream we get and its richness each day will vary with the temperature of the milk, the rate at which the milk goes through, or the speed of the machine. It is impossible on account of these factors to take a cream of a certain per cent, of fat each day. It is therefore necessary to take a richer cream than is desired and thin down with skim milk. In such a case as the one under consideration, it will not be necessary to test the cream for fat. If the separator skims close, practically all of the fat of the milk will be in the cream. We now add enough skim milk, 231.9 pounds, to the 45 pounds of cream to make the desired 5% milk, and 45.1 pounds of skim milk is left over. 115. Standardizing' from Ttvo Q,ualities of Milk. Another proposition in standardizing a certain amount of milk to a certain standard when milks of dififerent per cents, of fat are at hand is as follows : Example : Make 500 pounds of 4% milk from milks containing 5% and 3.2% fat. How much of each should be used to make the 500 pounds desired? 500 pounds of 4% milk contains 20 pounds of fat. 500 pounds of 5% milk contains 25 pounds of fat. 500 pounds of 3.2% milk contains 16 pounds of fat. Every pound of 5% milk contains .05 pounds of fat. Every pound of 3.2% milk contains .032 pounds of fat. 94 Elements of Dairying. Every pound of 5% milk replaced by 1 pound of 3.2% milk reduces the fat by the difference .05 — .032 = .018 pounds. 25 pounds — 20 pounds = 5 pounds of fat to be taken out by replacing 5% milk with 3.2% milk. .018 pounds is contained in 5 pounds 277 times. Therefore, 277 pounds of 3.2% milk is to be used in place of that much 5% milk, and 233 pounds of 5% milk will be required to make the amount up to 500 pounds. 283 lbs. 5 % milk contains 11.15 lbs. fat 277 lbs. 8.2 % milk contains 8.85 lbs. fat 500 lbs. 4 % milk contains 20.00 lbs. fat Q. E. D. These methods are applicable to the standardization of cream as w^ell as of milk, excepting that it may pos- sibly be necessary to test the cream to be used. 116. Value of Milk and Cream on Pat Ba.sis. A common problem that comes up in this connec- tion is that of the price of milk or cream by the gallon when the milk is bought on the fat test. For example : When milk of 4% butter fat costs $1.44 per 100 pounds, what will be the cost per gallon of, first, 5% milk; second, 20% cream. At $1.44 per 100 pounds, each pound of fat will cost 4 into $1.44. or 38 cents. A gallon of milk weighs 8.6 pounds and contains 5% of that weight, or 4.3 pounds of fat. which at 38 cents per pound would be 16.34 cents. More butter fat in the cream lowers the specific gravity so that a gallon of 20.% cream will weigh about 8.3 pounds and contain 1.66 pounds of fat, wdiich at 38 cents per pound would be w'orth 63.08 cents. Market Milk. 95 117. Modifley Food. Storr's Report, 1897, pp. 93-112, (E. S. R., Vol. X, p. 683). Mass. Report. 1900, pp. 14-21, (E. S. R., Vol. XIII, p. 385). N. J. Bulletin 123, September. 1897, (E. S. R., Yol. IX, p. 985). Feeding Fat Into Milk. Report XIX, Bureau of Animal Industry. 1902. 11;:^ Elements of Dairying. As Aft'ectetl by Exeiteiiieiit of Co^vs. By Dehorning, Wis. Report. 1889, p. 51, (E. S. R., Vol. II, p. 429). Composition of Milk for Cliee.se Making-. Wisconsin Bulletin (U, and Report XI, pp. 131-137. Geneva Bulletins, 37, 43, 45, 60, 61, 62, 65, 68 and 110. Creaniinft- of Milk. By Gravity. Cornell Bulletin 29 ; Illinois Bulletin 18; Indiana Bulletin 44; Minnesota Bulletin 19. Creaniins", «>< Affected by Feeding- Cotton Seed 3Ieal. Texas Bulletin 14. Wisconsin Bulletins 18 and 29. Creaming- by Dilution Creamers. Illinois, Bulletin 18; Cornell, Bulletins 29 and 151. Creaming- by Centrifugal Separators. Wisconsin Bulletins 29 and 56. Cornell Bulletin 66. Creaming- l>y Air Pre.ssure. Cornell Bulletin 39. Fat Globules. New York State Report, 1891, pp. 143-162 and 316- 318, (E. S. R., Vol. IV. pp. 264-271). Vermont Report, 1890. pp. 65-69, (E. S. R., Vol. Ill, p. 472). New Hampshire Report, 1888, pp. 84-88, (E. S. R. No. 2, part II, p. 107). Maine Report, 1890, p. 58. (E. S. R., Vol. III. p. 23). Pennsylvania Report. 1895, pp. 75-85, (E. S. R., Vol. VIII, p. 826). Wisconsin Reports, 1889, pp. 99-102, and 119-122, (E. S. R., Vol. IL p. 430); 1890, pp. 238-247, (E. S. R., Experiment Station Bullptins and Reports. 113 Yol. II, p. 454) ; 1893, p. 287, (E. S. R., Vol. VII, p. 559) ; 1894, pp. 223-239, (E. S. R., Vol. VIII, f). 337). Indiana Bulletin 24, (1889), p. 12, (E. S. R., Vol. I, p. 40). Tlife Feeding Value of Wliey. Wisconsin Bulletin 27. Flavor of Milk. Silage Flavor. Wisconsin Bulletin 59, May, 1897, pp. 25-28, (E. S. R., Vol. IX, p. 378). Fishy Flavor. New York Bulletin 183, (December, 1900), (E. S. R., Vol. XIII, p. 85). Absorption of Flavors. Wisconsin Report XV, p. 104. -Aeration. Wisconsin Report XII, p. 127. Galactase. A ferment (enzyme) natural to milk. Wisconsin Reports XIV, p. 161; XV, pp. 77-93; XVI, pp. 151-175. Historical. Wisconsin Bulletin 88 ; Report XIV, 1897, pp. 113 and 149. Ohio Dairymen's Reports, 1902 and 1903. Milk Production. Effect of Drouth Upon Milk Production; Geneva Bulletin 105 ; The Immediate Effect of Changes of Ra- tion, Geneva Bulletin 210; The Source of Milk Fat, Geneva Bulletins 132 and 139. Cost of Milk Production. Cornell Bulletin 52. Feeding Fat to Cows. Cornell Bulletin 92. Studies in Milk Secretion, Cornell Bulletin 152. The Milk Supply of Two Hundred Cities and Towns. Bulletin 4G. Bureau of Animal Industry, 1903. 114 Elements of Dairying. Pasteurization. Wisconsin Bulletin 44; The Efficiency of a Con- tinuous Pasteurizer,, Geneva Bulletin 172 ; Wisconsin Reports XII, p. 158, XVI, p. 121 and 129, XVIII, p. 177. Seci'etion of Milk. Dr. A. W. Bitting on Physiology of Milk Secretion,. Indiana Report XII ; The Udder of the Cow, Indiana Bulletin 62. Short's Saponification. Milk: Test. Saponifying and Setting Fatty Acids Free, Wis- consin Bulletin 16. Testing Cotvs. Wisconsin Bulletin 75; Reports XI, p. 205; XIII,. p. 164; XIV, p. 153; XV, p. 30; XVI, p. 140; XVIII, pp. 73 and 85, and 91. Viscosity. Wisconsin Report, 1895, (XII), p. 164 ; Report, 1896, pp. 73-80, Bulletin 54, (E. S. R., Vol. IX, p. 582). DAIRY LITERATURE. Dairy Books. The' followini? twelve books should be in every dairyman's library : Testing Milk and Its Products— Farrington and Woll. Outlines of Dairy Bacteriology— Dr. H. L. Russell. The Principles of Modern Dairy Practice— Groten- felt. Translated by F. W. Woll. Bacteria in Milk and Its Products— H. W. Conn. Handbook for Farmers and Dairymen— F. W. Woll. The Theory and Practice of Infant Feeding — Chapin. Cheese Making — Decker. Milk and Its Products— H. H. Win^. Three Pamphlets on Cheese Making, Butter Making and Pasteurization— By J. H. Mourad. The Creamery Patron's Handbook— Published by the National Dairy Union. Charles Y. Knight, Secretary, 154 Lake St., Chicago. 115 A HANDSOMELY ^^* IL»^.^JI_, ILLUSTRATED MAKING TEXT-BOOK Printed on Enameled Paper and Bound in Art Canvas. 6}4 \9)4 inches, 200 pages THIS BOOK TREATS OF THE MANUFACTURE OF CHEDDAR, BRICK, SWISS, LIMBURGER, EDAM AND COTTAGE CHEESE IT IS PUBLISHED BY THE AUTHOR OF ** ELEMENTS OF DAIRYING ** Any Dairy Supply House or Boek Dealer oan furnish it to you (postpaid) for $1.73 iivr o/ iij\j^ LIBRARY OF CONGRESS 002 852 480 8