HYGIENIC PRACTICES FOR CLEAN MILK PRODUCTION: A NEED OF THE HOUR

HYGIENIC PRACTICES FOR CLEAN MILK PRODUCTION: A NEED OF THE HOUR

 

Milk is an almost ideal food. It supplies many body building proteins; bone forming minerals and health-giving vitamins and furnishes energy giving lactose and milk fat. It is an excellent source of calcium and phosphorous, both of which together with vitamin D are essential for bone formation. All of these properties make milk an important food for pregnant mothers, adults, invalids, school going children, old persons and patients alike. Milk is, however a potential ready source for various disease-causing agents and other chemical and biological contaminants. In the last few years, the contamination of milk is considered as one of the main dangerous aspects.  

Milk is the whole, fresh, clean, lacteal secretion practically free from colostrum’s obtained from complete milking of healthy milch animals. The presence of chemical and biological contaminants in milk are very important for consumers and it can be a matter of public health concerns as well as many unknown diseases in human because milk and dairy products are widely consumed by humans throughout the world. So, from public health point of view, it is highly essential to take necessary hygienic measures at each step of milk production to reduce the level of such contaminants in the milk.

Clean Milk should have the following properties:

 

• Usually comes from healthy milch animals.
• Should be devoid of bad flavours and dirt and filth.
• Should contain relatively small number of bacteria
• Essentially free from diseases causing pathogens.
• Should have normal composition and acidity.

Purpose of clean milk production:

• To enhance the consumer satisfaction
• Poor quality milk is difficult to handle for further processing to produce some value -added milk products.
• To prevent milk borne intoxications and zoonotic diseases.
• To enhance Government revenue from the dairy subsector
• To enhance the Profit of the Producers. .

 

Factors Affecting Quality of Milk

Internal factors

• General health of cow (mastitis, tuberculosis)
• Stripping of foremilk.
• Stage of lactation.

External factors

• Animal body
• Milker hygeine and habits.
• Milking and storage utensils.
• Methods of milking.
• Feed and water.
• Milking environment.
• Cooling & heating of milk.
• Treatment of cows with antibiotics.

 

SOURCES OF CONTAMINATION

 

The sources of contamination of milk on the farm can broadly be categorized as

• Interior of the udder
• Exterior of the udder

The interior reflects the health of the animal, while the exterior depends on the farm condition, equipment’s persons, water etc.

INTERIOR OF THE UDDER

• The animal by itself is one of the most significant contributors of microorganism in milk.
• Microorganisms enter the udder through duct at the teat tip.
• During progress of a milking, bacteria are present in the largest number at the beginning and gradually decrease. This is mainly due to mechanical dislodging of bacteria, particularly in teat canal where the number are probably highest. Discarding the first few streams of milk results in lower counts of microbes in milk.
• Most of the bacteria are excreted in fore milk. When the animal is suffering from some disease, the causative organisms are also likely to come into milk depending upon the severity of infection.
• The most common disease in milch animal is mastitis and the primary causative organism; Streptococcus agalactiae is commonly present, even though no clinical evidence of mastitis is present in the cows. The other common mastitis causing organisms potentially harmful to humans are Staphylococcus aureus and Escherichia coli, occasionally Streptococcus uberis Streptococcus dysgalactiae. Some of the other organisms encountered occasionally are Listeria sps, Leptospira sp , Bacillus cereus, Pasteurella multocida, Clostridium perfringens, Actinomycetes, Coxiella burnetti and the Yeast Cryptococcus neoformans. The other organisms, which can come through the animal, include, Mycobacterium tuberculosis, Brucella abortus. etc .

Control

• Animals should be maintained in clean dry environment free from dust and dirt.
• Milk from the first few strippings should be discarded.
• Milk from the infected udder should be discarded.
• Dairy animals should be periodically vaccinated against susceptible diseases.

EXTERIOR OF THE UDDER

 

• Number and type of organisms associated with udder vary depending on type and amount of soil. Udder and teat become soiled with dung, mud, bedding material such as saw dust, straw etc. With heavily soiled udder teats the counts may be 1 lakh cfu/ml.
• Bedding material in winter has high number of bacteria, Main organisms in order of maximum numbers are psychrotrophs, coliforms, Bacillus sp. In summer cows turned to pasture, the number of bacteria in bedding declines.
• Udder micro flora is not affected very much by washing. Sodium hypochlorite washing and accompanied by drying help in reducing in number.

1. Teat surface and animal body:
2. Teat surface

Teat surface may also contain clostridia spores that are usually found in cows fodder, bedding & faeces.

Prevention strategies:

 

• Prevent regular soiling of teat surface.
• Wash with disinfectant. Quaternary ammonium compounds can act effectively, but presence of organic matter interferes with action of Chlorine & it is also irritant to hands.
• Drying of teats before milking.
• Cloths – Used for only one cow separately and moistened in sanitizers after each use. Paper towels are preferable.

 

1. Coat of Cow

• Coat serves as vehicle to contribute bacteria directly to milk.
• Clipping of hair around udder, flanks and tail reduces the count of bacteria in milk.
• Coat may indirectly contribute organisms into air of the barn, especially Bacillus sp. Coat may carry bacteria from stagnant water pools especially ropy milk organisms.
• Coliforms may gain from soil & manure.

 

Prevention strategies:

Periodic clipping of hair and regular brushing of coat should be done. Machine milking practice should be adopted.

2. Milking barn and the environment:

 

• The house keeping practices in the milk producing area also decide the level of contamination.
• The accumulation of mud, animal urine and faces, the left-out straw and feed in the milking barn can directly or indirectly through air milk can be contaminated.

The following practices that increase aerial counts through milk in milking barn:

• Sweeping short time before milking
• Handling hay and feed just before milking
• Brushing animals just before milking
• Having dusty bedding material
• Allowing dust and dirt to accumulate on wall and ceiling.

 

Prevention

• The environment in the milking barn should be clean.
• The aerial contamination can be prevented by the use of small top milk pails and milking machine.

3. Milking utensils

• The improperly cleaned ‘milk contact surfaces’ of milking equipment’s including bucket, pail, cans, bulk tanks etc. are the only source of contamination in milk after it leaves the udder.
• The most hazardous situation arises when the milking utensils are not thoroughly cleaned after use and the milk solids with some moistures are left on the surfaces.
• These allow growth of microorganisms and heavily inoculate the fresh milk, which comes in contact with these utensils.
• When mastitis is prevalent in the herd, the utensils may contain Streptococcus agalactiae, Staphylococcus aureus, E. coli or Corynebacterium sp.
• When hot cleaning of equipment is done, the predominating organisms are thermoduric, mainly Bacillus sp. and Micrococcus.
• When cold cleaning is followed, heterogeneous microflora’s are present.

 

Control

 

• The milking utensils and equipment’s should be cleaned and sanitized before and after milking.
• The tanks used for bulk transport of milk should be cleaned and sanitized immediately after the unloading of milk.

4. Milker:

• When hand milking is done, the contribution from milker is high.
• Milker with infected wounds on hands contribute pathogenic streptococcus & micrococcus
• Activities like sneezing, coughing etc. increase the risk of contamination.
• During the wet hand milking lubricant enters milk and adds bacteria from hands and teats. Pathogens causing typhoid, paratyphoid, dysentery, scarlet fever, septic sore threat. Diphtheria, cholera etc are contributed from humans. Action of milker may dislodge dust and dirt and increase air contamination

Control

• The hands of the milker should be clean and he may dip his hands in antiseptic solution before milking.
• Unhealthy milkmen should be avoided.
• Bad habits like coughing and sneezing should be prevented within the milking barn.
• Milkers should do their health checkup at every 6 months interval as routine practice also.
• They should receive vaccines against the cholera, typhoid, dysentery etc…which are generally gets transmitted from human beings to milk

5. Water supply

• Water used should be potable & good in terms of bacteriological quality.

Direct sources of contamination are:

• Storage tanks, not protected from rodents, birds, insects and dust.
• Hoses
• Water troughs
• Untreated water supplies from bore wells, lakes and rivers may be contaminated at source with faecal streptococci, Coliforms, G-ve rods, Lactic acid bacteria, Bacillus sp., and corynebacterium sp.

Control

Water used for cleaning should be free from faecal contamination and water may be chlorinated before use. Chlorination – with hypochlorite’s is recommended.

 

6. Milking machine

• Milking machines are used when large numbers of animals are to be milked at a time.
• As milk production in India is mainly through marginal farmers in very small scale, the milking machine is rarely used.
• However, when they are used, proper care is required not only in its cleaning but also in its use, because its improper use may damage the udder and thereby increase risk of contamination.
• When pipelines are reused for direct milk collection, their improper cleaning and sanitation add further to the microbial load of milk.
• The types of microorganism coming from milking machine are similar to those coming from other equipment’s.

Control

Milking machine should be cleaned and sanitized by using iodine sanitizers as a routine practice.

7. Storage and transport

• Mainly the psychotropic and thermoduric bacteria contaminate the milk through unclean milk cans and bulk milk transport tankers.
• Among the psychotropic genera in stored milk, Pseudomonas sps. flourescens generally predominates.

Control

Milk should be stored and transported between the temperatures of 0-5 ° C.

 

Strategy for clean milk production

1. Awareness of the public through different training programmes
2. Managing the animals at the farm
3. Feeding the cow
4. Proper housing c.  Animal health management
5. Managing the somatic cell count (scc)
6. Managing the hygiene of milking equipment and utensils
7. Managing hygiene
8. Milk cooling

 

https://www.pashudhanpraharee.com/clean-milk-production/

Hygienic Practices During Milking

In Small farms:

• Animal either milked in stanchion or in standing area
• Teat cleaned with cloth or with bucket of water
• Concentrate is offered prior to milking.
• Hand milking is usually done
• After milking roughage is provided
• Filtering of milk with cloth/filter should be done.
• Frequent washing milking bucket should be done.

 

In Large farms:

• Bringing animal to holding area
• Keeping & washing in holding area
• Taking inside parlor & tying
• Washing udder + disinfection+ drying
• Offering concentrate mixture
• Apply machine Milking
• Post milking teat dip + spray
• Taking animal back to paddock
• Washing parlor
• Washing milking equipments & drying

Standard Milking Procedures

1. Fore stripping

• For 10-20sec of teat stimulation
• To identify cows that have mastitis
• 2-3strips per quarter
• Never stripped on to bedding

 

2. Predipping

• Dipped into 0.5% iodine
• At least 3-4^th of each teat should be covered
• Contact time: 30sec
• Teat should be vigorously dried
• Special attention paid to the teat end

 

3. Attaching miking unit

• Attached within 1-2min after stimulation
• Blood oxytocin level peaks at 60sec
• Minimize the entry of air into milking system
• Takes 7-8min to complete milking

 

4. Checking during the milking

• Carefully watch for cessation of milk flow
• Keep the machine for shorted duration of time
• Machine strip the cow for complete removal of milk

 

5. Detaching milking unit

• Automatic take offs are recommended as they do most consistent job of removing milk
• Important that animal are not over milked
• First put off vacuum, then remove machine gently

 

6. Post dipping

• The lower one-third of each teat must be dipped with teat antiseptic
• Done after every milking

 

Milking Management

1. Prepare cows properly for milking

Keep cows clean, udder free from soil and manure

• Pre-dips
  • Iodophors (0.5 -1.0 %)
  • Chlorhexidine (0.2%)
  • Quats (0.5%)

2. Good milking system
   • Milking equipment
   • Full hand milking
   • Functioning of milking machines
   • Prepare udders
     • Single service paper towels, dry teats before machine-application
     • Provide stable vacuum

Shut of vacuum before removing teat cups

3. Apply and remove machine carefully

• Adjust to prevent liner slippage
• Remove machine when cow is milked out
• Shut off vacuum at claw before removal

4. Post-dips

• Post-dips seal the teat ends 6 to 8 hours

5. Monitor mastitis score (SCC) regularly
6. Segregate chronic mastitis cows

• Cows with chronic mastitis are reservoirs of organisms and could infect susceptible cows
• Milk them last and Cull when necessary.

 

Conclusion:

Maintaining hygienic practices during milk production at the farm level will definitely reduce the level of various chemical and biological contaminants in milk and also will reduce the the transmission of milk borne zoonotic diseases to human beings.  So, dairy farmers should be provided with awareness training programme regarding the importance of clean milk production, sources of contamination of milk. So, that the farmers can get better benefit from dairy farming by preventing the spoilage of their product as well as by enhancing the consumer satisfaction.

---

1. P.K. RATH^1* AND B P MISHRA²

¹Assistant Professor, Department of Veterinary Pathology, ²Assistant Professor, Department of Livestock Products Technology, C.V.Sc. & A.H., OUAT, Bhubaneswar, Odisha

^*Corresponding author: drpkrath78@gmail.com

 

Reference-https://www.researchgate.net/publication/326728932_Clean_Milk_Production_Practices_Adopted_by_the_Dairy_Farmers_of_R_S_Pura_in_Jammu_District