SUGGESTIONS CONCERNING THE HYGIENE OF COW-STABLES AND THE PRODUCTION OF MILK FOR INFANT-FEEDING, WITH SPECIAL REFERENCE TO TUBERCULOSIS.

The Bonn Rules.

1. Until it has been definitely decided whether or not my protective cattle inoculation protects cattle against tuberculosis when these are kept in stalls or herds strongly infected with Tb. virus, it should be sought to reduce the danger of infection as much as possible by following Ostertag’s recommendations and segregating all the cattle with an open tuberculosis.

2. The milk of cows which react positively to tuberculin must not be used for feeding calves, nor, of course, for infant-feeding.

3. Whenever the circumstances permit, the separate housing of the protectively inoculated animals in a stable free from tuberculosis is to be recommended. In constructing new stables it is strongly urged that in place of one large stable, several small ones be erected; besides this, attention should be paid to the placing of the animals. They should be placed with the heads toward the lateral walls, and not head to head, facing a common feeding-trough along the middle of the stable.[7]

4. Particular attention should be paid to the cleanliness of the feeding-troughs. Every fourteen days they are to be filled with hot water and freed from any adherent dirt by mechanical means. The feeding-buckets are to be similarly cleansed from time to time.

5. The drinking-water supplied to cattle should meet essentially the same requirements as are demanded of water supplied to dwellings.

6. In maintaining the health of the young cattle an important factor is the pasturage. For larger dairies an arrangement used at our Marburg experimental station, consisting of a lightly constructed shelter within a large enclosed pasture, is to be recommended.

7. The disinfecting of infected stables is to be done in accordance with the government regulations.[8] [This refers to the German regulations of June 23, 1880, and May 1, 1894.] Here it is to be remarked that disinfection of the stables by means of formaldehyde generation is not even then accomplished when one far exceeds the requirements formulated by Flügge for the Breslau method. Utilizing the opportunity presented by a number of courses given at Marburg in the method of making protective inoculations, etc., we have found that even in the stable of the pest laboratory here, which is very easily closed off, the above-mentioned formaldehyde fumigation is ineffectual; for by treating the disinfected objects with ammonia water it was found that neither anthrax virus nor cocci, in the dry state, were certainly destroyed by the fumigation.

8. More important than the disinfection by means of chemicals is the prevention of the accumulation of infectious materials on the stable utensils, in the food, on the body surface of the cattle, on the body and clothing of the stablemen. Training the stablemen to the use of warm or hot water and soap; the use of towels and dishcloths which have been rendered germ-free by means of hot water or dry heat before throwing them among the soiled clothes; special regard to a rational care of the milker’s hands, including the removal of the dirt under the nails; all of these are the most important measures for the prevention and suppression of stable infection.

9. If it is desired to secure a milk as free from dirt and germs as possible (not over 400 germs per c.c.), the following additional measures must be taken:

I. Presupposing that the milk is to be used for infant-feeding, the same is to be filled into bottles holding 250 to 500 c.c. All parts of the bottle, including the air-tight and germ-tight closing contrivance, must be constructed so as to be readily cleansed, and further, so that they can, without injury, be sterilized by heat.

II. In order to meet all the requirements for cleansing and sterilizing milk-bottles, the following rules are recommended. The bottles returned by the consumers are in a soiled condition and contain fluid remnants of milk:

(a) The cleansing of the bottles should be undertaken in a well-ventilated room which can readily be kept clean and which may also serve as the bottling room. This room is to be so separated from the stables that the stable odors cannot gain access.

(b) The following manipulations are required to clean the bottles:

(α) Energetic rinsing with 10% warm soda solution.

(β) Rinsing with quartz gravel by means of a stream of hot water.

(γ) Cold rinsing.

(δ) Sterilization in the dry chamber. These cleansing manipulations occupy about forty-five minutes.

III. The stable itself should be so built that it can readily and thoroughly be cleansed, with special regard to the following points:

(a) Draining of the fluid excreta, etc., by means of drains with sufficient pitch.

(b) Ready removal of solid refuse without raising dust.

(d) Good ventilation for the high lying stalls.

(e) Broad alleys separating the rows of stalls.

(f) Each stall to be constructed in such manner that the cow is obliged after feeding to step back, thus compelling her to empty her excreta into an open drain connected with the main drain. This is effected by means of the so-called “drop-railing contrivance.”

(g) Water-tight flooring.

IV. The spreading of peat instead of straw to keep the stalls dry.

10. Another deciding factor in the production of a pure milk for infant-feeding is the cleanliness of the stable and dairy attendants, the milkers, the cows, and the stable and dairy utensils.

I. Aside from general body cleanliness, particular attention is to be given to a healthy condition of the milking person’s hands. Before proceeding to milk, these persons are to don a clean gown made of white linen.

II. The cows are to be kept scrupulously clean. The udders and tails are to be so clean that they can be touched with white-kid gloves without causing appreciable amounts of dirt or of odorous substances to soil them. In order to keep the udder and teats clean the following is recommended:

Just before milking, the udder, which should always be kept dry, is to be rubbed off with a clean flannel cloth which has been greased with a little lard. By this means dirt and odorous substances are most readily removed. Following this, the parts are rubbed dry with the aid of a little bran.

III. The milk vessels should be of tinned sheet iron.

IV. The milk should be strained through aluminium-nickel gauze or brass gauze, which is then to be cleaned and disinfected.

V. All the milk of one milking period is pumped high into the bottling room and conducted into a collecting reservoir. This passage to the reservoir, during which it is cooled and aired, occupies only a few minutes and the milk reaches the reservoir at a temperature of 4°-5° C.

VI. From this reservoir the milk is bottled without delay by means of a bottling-machine, the milk having a temperature of about 5°-7° C. on bottling. A temperature of less than 2° C. has an injurious influence on the anti-bacterial substances in the milk, and should therefore be avoided.

11. If the milk hygienic rules above mentioned are carefully followed, and if attention is paid to the experiences regarding a rational method of feeding milch cows, it is possible, without any further method of preserving the milk, to have the same capable of being transported and kept for sixteen hours without losing its adaptability as infant food. In Berlin I saw such a milk reach the consumer with a germ-content of not over 1000 germs per cubic centimeter. On the other hand, I have seen milk derived from dirty cows and collected without particular hygienic precautions, after being transported six hours, contain a hundred to a thousand times as many germs. In such cases, soon after milking, the milk often contains from 30,000 to 100,000 germs per cubic centimeter.

In the strictly fresh milk from my own cows the number of germs per cubic centimeter varies from 10 to 50 to 200. Such milk kept at room temperature does not coagulate until after three to five days.

At present I regard 1000 germs per cubic centimeter at the time of feeding to be a safe limit for milk fed to infants.

12. If a milk collected in accordance with the preceding regulations is to be made capable of being transported and kept for three days (in which case coagulation factors must be reckoned with) without losing its qualifications as an infant food, the addition of formaldehyde in the proportion of 1:40,000 (B. f. milk) is to be recommended.

The following manipulations are then to be carried out:

I. Preparing a formaldehyde stock solution containing 0.5% formaldehyde. (One part of commercial formaldehyde and 79 parts of boiled water.) This solution will keep for two or three days.

II. Pouring 50 c.c. of this 0.5% stock solution (= .25 gramme formaldehyde) into an empty tin pail in which a mark has been made at the 10-liter level.

III. Milking into this pail up to the mark.

IV. Straining, airing, cooling, etc., according to paragraph 10, IV, V, and VI.

13. In order not to conflict with the government sanitary regulations the milk producers at present delivering this B. f. milk have agreed to supply it only to certain private institutions designated by me.

14. Should the authorities later decide to allow the sale of this B. f. milk, it is recommended that licenses be issued, out of the proceeds of which veterinary physicians be appointed to see that this B. f. milk is produced in accordance with these regulations.

15. Containers for B. f. milk should have trademarked labels indicating that the milk has been produced in conformity with the requirements. Beside this the label should bear in clear figures the time and date of milking.

16. Whenever for any reason it is impossible to raise a calf directly on the udder, B. f. milk should be preferred to milk sterilized by heat. In the production of B. f. milk tubercular and suspected tubercular cows are to be excluded on principle.

17. Where it is desired to suppress an infectious process in the digestive system of cattle, the temporary employment of a stronger formaldehyde milk (1:25,000 to 1:16,000) under the direction of a veterinary physician is recommended.

18. In the suppression of “Kälbersterbe,” beside the increased requirements regarding the cleanliness of attendants’ clothing and body, of stable and stable utensils, the proper care of the navel with the aid of ⅖% aqueous solution of formaldehyde is recommended.

19. The radical suppression of bovine tuberculosis by means of my protective inoculation is to be sought for.

20. The following article shows the method of making these inoculations at present in use at Marburg.