FR y Py eprne Pave te = ah me Hs Lf zed eens coy t i Dig * patch ar bie ney rf \ ’ ‘ Sp si ere LIBRARY NEW YORK STATE VETERINARY COLLEGE ITHAGA, N. Y. <= Sl Seek Gi¢t ot Mies Helena H. Haight. Digitized by Microsoft® This book was digitized by Microsoft Corporation in cooperation with Cornell University Libraries, 2007. You may use and print this copy in limited quantity for your personal purposes, but may not distribute or provide access fo it (or modified or partial versions of if) for revenue-generating or other commercial purposes. Digitized by Microsoft® Cornell University The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http:/www.archiye.org/details/eu31924000000640 igitiz Croso Digitized by Microsoft® Digitized by Microsoft® PURE MILK AND THE PUBLIC HEALTH A MANUAL OF Milk and Dairy Inspection By ARCHIBALD ROBINSON WARD, B.S..\., D. VM. Assistant Professor of Bacteriology and Director of the State Hygienic Laboratory. University of California, Berkeley, California. WITH TWO CHAPTERS By MYER EDWARD JAFFA, M.S. Professor of Nutrition and Director of the State Food and Drug Laborators University of California. WITH SEVENTEEN ILLUSTRATIONS ITHACA, N.Y. TAYLOR & CARPENTILK 1909 Digitized by Microsoft® COPYRIGHT 1909 By ‘TAYLOR & CARPENTER ws 2413 Digitized by Microsoft® TO VERANUS ALVA MOORE WHOSE INSPIRING WORK AS \ TEACHER AND INVESTIGATOR IN THE FIELD OF COM- PARATIVE PATHOLOGY AND BACTERIOLOGY IS EXERTING A PROFOUND INFLUENCE IN UPLIFTING THE VETERINARY PROFESSION, THIS BOOK IS DEDICATED. Digitized by Microsoft® Digitized by Microsoft® PREFACE. The relation of milk to the public health and the means employed to ensure a safe milk supply is a subject of varied aspects. The proper control of the public milk supply requires more or less of the services of the bacteriologist, the chemist, the physician, the veterinarian, and the progressive dairyman. The ordinary fund of technical knowledge possessed by any one of these classes is not sufficient for coping with the difficulties encountered in carrying on efficient and comprehensive meas- ures for milk and dairy inspection. Furthermore, knowledge concerning the subject is being rapidly increased by contribu- tions widely scattered in technical journals. The writer has attempted the difficult task of assembling the essential facts for the information of the health officer and others directly concerned in the crusade for better milk. The class of individuals particularly addressed is such, that a gen- eral knowledge of bacteriology is assumed to be possessed by the reader. Each chapter is accompanied by a list of references bearing on the subjects discussed. .Throughout the text, numbers in parenthesis, referring to the authorities given at the end of the chapter, have been freely used. These references serve in some cases to give statements greater weight than a mere unsup- ported personal opinion would have, and in all cases permit those particularly interested to gain access readily to the details concerning the points at issue. In the preparation of the book, the writer has become greatly obligated to his colleague, Professor M. E. Jaffa, for writing chapters X and XI. With reference to those chapters, Pro- fessor Jaffa desires to have it stated that he has not attempted to present the details of the more common methods employed in the chemical examination of milk. This branch of milk inspection is the most advanced and the methods are well estab- lished. He has been content to indicate what should be done Digitized by Microsoft® VI PREFACE. and to refer to standard works on the subject for the methods except in the case of some of the simple tests. Dr. William H. Boynton, Assistant in Pathology and Bac- teriology, New York State Veterinary College, has very gener- ously permitted the use of the photographs appearing as figures 13 and 14, together with his description of them, in advance of publication by himself. Professor G. C. Watson, General Manager of the Tully Farms, Tully, N. Y., has kindly per- mitted the use of photographs appearing as figures 3 and 4. Dr. Francis H. Slack, Chairman of the Committee of the American Public Health Association on Standard Methods of Bacterial Milk Analysis, has rendered assistance by furnishing a manuscript copy of the 1908 report of that Committee. Specific acknowledgement as to sources of information has been made largely throughout the text by means of the system of references employed. It is not safe to indulge in the hope that important work has not been overlooked, or that new facts may not require a modification of attitude towards certain troublesome problems. Therefore, assistance tending to improve the book will be gratefully received. A. R. W. Digitized by Microsoft® TABLE OF CONTENTS. LIST OF FIGURES IN TEXT... 0. eerey eet uy Bes XII CHAPTER I. THI, CONTAMINATION OF MILK. Udder 1 Character of bacteria 3 Significance 4 Foremilk S) Coat of animal 35 Exterior of udder 6 Shape of milk pail ii The milker Ss Milking machines Ss Stable 10 Floor 10 Manvers and stanchions 11 Barn improvements 11 Feeding 12 Special milking rooms 2 Cleansing of utensils 13 ; Scalding 13 Construction of utensils 15 Handling milk ; 15 Bottling milk. 16 Milk room. 16 Delivery of milk 16 Milk flavors 17 Sediments 2 17 References 18 CHAPTER II. CHANGES IN MILK CAUSED BY BACTERIA. Significance of bacterial contamination BO ass 23 Numbers of bacteria in market milk 24 Effect of temperature on bacterial growth 24 Methods of cooling: © ©0 25 Milk during transportation . 25 Preservation by chemicals... |... : 26 Digitized by Microsoft® VIII CONTENTS. Lactic acid fermentation . ........ Putrefactive processes...........22.0: ce aor aes traawerntne Organisms causing putrefaction... Antagonism of lactic acid fermentation................ : Conditions controlling putrefaction 2000000000000 1... Source of putrefactive organisms 20.0.0. oe Toxic milk Ropy milk CausecOf ropy- snide go. .c3 cee cece bcaleas abe .sviaes dog deacons Biological characteristics of B. lactis viscosus Sources of contamination of milk 00 20.000. Means of combating ropy milk 0000 0 Gerniicidal activity. ......... References CHAPTER III. EPIDEMIC DISEASES TRANSMITTED BY MILK. Transmission of diseases of man by milk Character of milk-borne epidemics DOU BOT cs npc Hen Seca ele hd Investigations in the District of Columbia.. Importance of milk as a carrier.. : Sources of the contamination of milk 00000 ee. Detection of milk-borne typhoid fever epidemics ....... .... Berkeley, Cal., outbreak Diplhitheria Recognition of milk-borne diphtheria epidemics... _ .. Milk-borne diphtheria in Oroville, Cal.- Scarlet fevers. asuweh ee eee: Se bGR, Shon Mae wes Gastro-intestinal infections ... References... a b AR Gotten Saaderins CHAPTER IV. BOVINE TUBERCULOSIS AND OTHER CATTLE DISEASES. Transmission by milk .... Infection of swine Insidious onset .... .. Pe oak Conditions governing prevalence Human and bovine types of tubercle bacilli. Digitized by Microsoft® 41 41 42 42 43 45 46 49 51 52 53 54 55 56 CONTENTS. Views of Koch | oo... Bovine tubercle bacilli in man... ....... Intermediate types of tubercle bacilli Channels of infection 0.0.00... International Congress of 1908. Tuberculosis in Japan Present status of controversy Protection of the milk supply Measures against bovine tuberculosis Physical examination Tuberculin test New tests for tuberculosis Stable sanitation and tuberculosis Tuberculin test ordinances Clean herds the goal The Washington plan Test by city official Test by any licensed veterinarian Milk contracts ; Application of the tuberculin test ‘Temporary numbers Facilitating observations of temperatures Injection with tuberculin Temperatures after injection Interpretation of temperatures Limitations of tuberculin test Fraud Permanent identification of animals Disposal of tubercular animals Disinfection Education of dairymen concerning bovine tuberculosis Anthrax Suppuration Cowpox ; Parturition disturbances Malta fever Foot and mouth disease Milk-sickness References CHAPTER V. MUNICIPAL SANITARY CONTROL OF MILK. Control of milk supply Inspection The dairy score card Digitized by Microsoft® x CONTENTS. Improvement in Richmond, Va........ Washington milk supply ........... Educational activities .... Inspection of cows. pase. Inspection of dairy anparatne 5 Pes 2 Inspection of water supply. ... Scope of inspection a The score card for city wilile nian, Milk-borne epidemics 2... 0 2.00 0 Temperature standard... Numerical detexminakiaws ‘ot Hinton 4 in ee satemee Education of the public .... Mok preted Cea References ... CHAPTER VI. PASTEURIZATION OF MILK. General definition .. Babe Incentives for pasteurization .. Conditions required for killing panes Bacterium tuberculosis Alteration of milk by heat. Cooked taste Alterations of milk constituents Creaming quality ..0..00..... Vital qualities of milk Spore-bearing bacteria... 000 00000... Bactericidal efficiency. ........... ED foe Low-temperature pasteurization.. ...... High-temperature pasteurization......... Commercial pasteurization ..... AT CIC CY ass, ,sawnentige nie<cotemnenns your ss Continuous-flow machines popular... Care subsequent to heating Pasteurization in Chicago... Pasteurized milk in infant feeding... Pasteurization of municipal milk supplies. References 0......... CHAPTER VII. MICROSCOPIC TESTS OF MILK. Mamuiitis in the cow... Pree Tests for cellular content of milk 00000 0... Stokes' test 00000000 1. Digitized by Microsoft® 103 104 104 105 105 106 ... 106 .. 106 109 109 110 142 _ 112 114 114 115 115 115 115 _ 115 116 116 116 117 117 118 118 _ 119 120 121 121 122 123 124 CONTENTS. Slack’s test Doane-Buckley test Savage's test Tromimsdorff's test Significance of results Streptococci in milk Microccocci in milk Leucocytes in milk Summary Bloody milk References CHAPTER VIII. BACTERIOLOGICAL HXAMINATION OF MILK Numerical determination of bacteria Significance of results Microscopic estimate of bacteria Tests for 2. coll Examinations for typhoid fever and diphtheria bacilli ‘Tubercle bacilli Determination of streptococci Qualitative determinations References CHAPTER IX. CERTIFIED MILK Milk commissions - Association of milk commissions Source of authority - Field of milk cominission activities Agreement with dairymen Sanitary requirements for dairymen. Experts employed by milk commissions . Veterinary inspection Bacteriological examinations Chemical examinations Medical inspection .. The certified milk packae: 1.2 ES, aes Ae Amount of certified milk proceed’ Sas BE NS Fraudulent certified milk Maintenance of standard... Sa. Go mvectoant, whose Milk dispensaries... ©0000 ee Rochester, N. Y., fille dispensaries.. References Digitized by Microsoft® 141 150 151 152 152 153 154 ist 155 XII CONTENTS. CHAPTER NX. THE ANALYSIS OF MILK. Introduction. : 174 Composition of milk 174 Protein. ae F 174 Fat... .. 174 Carbohydrates Meee lee ads .. 176 Mineral matter.. , — 176 Solidsvef milky... 222 22:25 See n : 176 Effect of feedine’non AhE composition of smile, dy .. 176 Sampling milk. ; ‘ 177 Specific gravity : ct 177 Determination of fat in serie ands cream : 179 Interpretation of specific gravity and fat. 180 . Solids not fat.. E , : 180 Preliminary tests of milk j 182 Acidity of milk : é 182 Federal standards 2 183 State standards 184 Collection of samples 184 References 185 CHAPTER XI. ADULTERATION OF MILK. Introduction... ory Bein oie Pied Bs comin LSet Tests for preservatives eh: sentences oy Geiger 90 Borax ........... catalog, Urnoemenva tl:& : PL 190 Pornaldehwdlé... d, siigenadiencs gieemen, Sueaare Ses Ge Ae sp aethinscte verad OO) -Hehner’s test for fovnialdetie de = waits ds f — cmos LO Leach’s test for formaldehyde ee pong VOL Watering of milk... hy ity GoD 2, enedeena ec ntade tek 191 Skimming... % 8 & gemiee Sp eet essiiriokets |alee 192 Carbonate of soda. ....... 2 : eS ate, OD Thickening agents for creain ....... ..... iighe Saie tsa gi ; a 193 Heated milk) 0 0 ih Gg eee EI tee a depres AOS Coloring matter... meee fy3. : 193 References _... Z 194 FIGURES IN TEXT. Fig. 1. Section of one quarter of the udder ofa cow. ..._.. 1 Fig. 2. Pearson's milk pail... oe 7 Fig. 3. A convenient stable Geen eeees sen hodihena: eae LO) Digitized by Microsoft® ILLUSTRATIONS. Sterilizer containing racks for holding bottles Ropy cream lifted with a fork. Bacillus lactis viscosus Germicidal action of freshly drawn ate, Laundry in which milk cans were washed... Conditions surrounding a case of typhoid fever Blank for recording temperatures. Ear-tag for marking cattle Card employed by the writer for the identtextion of ¢ cows Moak's card for identifying cows Diagram showing improvement in dairy scores in Rich: mond, Va. Section of udder showing epithelial cells. Section of udder showing epithelial cells and polynuclear leucocytes Chart showing relation of municipal nile stations to infant mortality APPENDICES. Appendix A. Dairy ordinance of Berkeley, Cal. Appendix B. Chicago tuberculin test ordinance Appendix C. Duluth milk ordinance. Appendix D. Blank for reporting existence of infectious diseases Appendix E. Poster for dairy barns Index Digitized by Microsoft® XIII Digitized by Microsoft®