DAIRY HYGIENE

Hawke's Bay Herald-Tribune, Issue 16, 3 February 1937, Page 15

DAIRY HYGIENE

Cleanliness Essential To Maintain Quality FIGHTING BACTERIA Tbe vital importance of tbe production of high quality milk and cream if tbq standard of New Zealand 's dairy produce is to b® main.tained and improved is empbasised in tbe follow;ing letter from Mr W. Percival Levy, of Auckland. . Mr Levy's comments were inspired by a ?§c§nt magisteri&l fllecisipn in Taranaki permitting a supplier to cbange from one dairy' factory tp anotber. "Tbis is a very serioup matter, as tbe wbole industry in tbe future wiU be so greatly affected by the quality of our production," writes Mr Levy, wbo continues as follow: — It is a tragedy tbat so littl® ie real-i ised by the vast numbers engaged in tbe dairying- industry to-day, from tbe production to tbe manufaoturing, o£ the vital importance of a rigid enforcement of a dairy sbed hygiene tecbnique. I do not for onq 'moment wisb to imply tbat tbose engaged in tbe industry are carelesg and dirty, but they ara ignor-i ant 9f tbe cause and effeet of eur prea-ent-day mctbods. Tbe time wiU come when a different itandard of botb milk and. cream greding will be iuaugurated,. when grading wiU b® done ©a tbet prganism mt bacteria content pf both. milk and cream and to reaeb tbe stand--ard required a dairy sbed hygiene tecbnique will be enforced. No butter maker can make a high quality butter •from a low quality cream. An Interesftug Experienca Tbousands of our prpduc§rs are will"; ing and anxioua to produce tbe bigb-j egt quality cream possible, but ignorance of the vital part played by tbese tiny organisms (bacteria) is preventing tbem from fioiQg 8Q« My own experience was precisely tbe same. I was milking over 200 cows asd bad sbeds and equipment of the latest deaign and _ anyone accusing me of producing an inferior quality cream was ridiculed.;, When my cream wag graded low ij blamed everybody but myself. I even| went so far aa to tbreaten to take my: supply to anotber factory, Tbe company 1 was eupplying sent an inspector to inspect my sbeds anQ found evqrytbing bl ' first-c'lass order, ' and could find no reason wby my cream sbould not be finest. Not until I com--menced aupplying fresb milk to tbe i city did I find tbat tbere was something radically wrong at tbe producing end. Consistently, I was finding tbat a portion of botb morning and evouing milk would not remain fresb for more ■tban 12 hours, and yet 70 per cent. would be quite fresb at 18 to 24 hours. Tbis ppsition to me seemed impossiblp. For a long time I would not agroe tbat tbere was any difference between one can of milk and anotber, but so persistent was this trouble tbat I bad, to investigate it. ' Source of tbe Trouble. | It was found tbat certain cans contained many tbousands qf bacteria more tban did tbe otbers. Following tbese cans through by identifying tbem, it was found tbat tbe trouble was witb tbe first few cans off tbe machines. What was bappening after each milking was tbe machines would ba siuiced witb cold water then bot water. Tbis bot water left tbe milk lines at sucb a temperature as to start an incubation of bacteria. Tbis propagation would go on until next milking, when witb tbe first cpwB being milked, tbe milk iiae of tbe macbine would be flushed. Sucb' fiushing would carry tbe bulk of tbe bacteria into tbe first can or so, and sulted in causing tbe milk to sour in a . very few hours. Tbe milk tbat followed would have anything from 12 to 20 bours longer, life than the first from tbe machines. This is tbe foundation of du? trouble. right throughout tbe dairy jndustry to-day, Stages of Incubation. For cream production tbe tecbnique is even more important tban fresb milk as tbe cream is beld longer before dclivery to tbe factory, during wbicb time propagation of bacteria is going on apace until cbecked ■ at tbe manufacturing end. Actually tbere are two stages of in-' • cubation • of bacteria after every milk-. ing. Gne is by leaving tbe milk lino in a perfect state of incubation by tbe sluicing witb bot water, tbe otber is in tbe vat during milking. Tbe milk beld in tbe vat bas a temperature of between 92 and 94 degrees, perfect incubation beat. At tbis temperature one bacterium will multiply at the rate of 72,000,000 in 24 bours. Tbis milk is then put tbrougb the separator and tbe temperature of tbe cream. from tbe separator is approxiinately 90 degrees, still at a perfect incubation beat. Tbis cream goes into tbe can in solid fat form, tbus retalning its tetnperature for a long period, during wbicb time our enemy bacterium is propagating at a terrifio rate. f How to Fight Bacteria. ; Tbe only way to prevent tbis .daily crop of contamination in our milk and cream is to make tbe conditions im- ' possible for bacteria to live in, and |tbis can only be done by a daily 'bygienic routine, as follows: First, all equipment is rinsed in cold water t6 remove all casein from utensils, tben witb an ample supply of bot water, and tben, tbe most important, a supply lof wet stcam to kill all living organisms wbicb are still adberent to all equipment. If tbis is done tbe milk from tbe subsequent milking will be; icemparatively free from «ontamination.j

[Tbe eream tben, sbould be cooled to e (temperature to prev'ent any bacteria from propagating. At a . temperature of between 60 and 65. degrees sucb propagation is negligible. -Cream treab ed in tbis manner will, if graded cor* rectly (feedy fiavour excepted) receiv© a grading bigber tban was ever bitborto thought of. . : • Keeping Quality in Milk. In conclusion, I can at tbis inoment ,give a very vivid fexample of ■ what effect a bigb standard of dairy sbed -hygiene can produce. My milkman bas supplied us for tbe past six years and during tbe summer montbs we bad difficulty in keeping milk for 24 bours. Some tbree months ago a steam steriliser was instaUed in bis dairy sbed and immediately tbe effect was evident. At tbe moment a cup of milk stands in my cupboard from the evening milking of Thursday last. It is now 10 p.m. Sun* day, approximately 77 bours old and in still perfectly sweet. Tbis ia only Ma of many hundreda of simi'iar Ulustrations I have bad during my ievesH*'"**'"' 4,,,n vary imiportant subject, and tbe fact of allow iug a supplier to cbange bis . supply on account of not being satisfied witb tbe grading be is receiving fills me witb borror as to what sucb an action can lead to. Graders will become ner« vous of losing tbeir supply if they grade low: borderline cream will get tbe benelit of tbe doubt, and as a result tbe manufactured article must suffer. Tbe only way to prove that a supplier 's cream is not up to standard is to take a bacteria count test. Let bim contest bis grievance on tbat test and I venture to say tbere would be very few suppliers wbo could justify tbe right to leave tbe factory tbey are1 I supplying.