India is the largest milk producer in the world and holding first rank, but the quality of milk produced in India is questionable. The export of milk and milk products from India to the international market is far behind than that of developed countries, hence farmers don’t get better price. In order to get high quality milk, certain hygienic practices such as appropriate sanitation and disinfections of the animal shed, utensils and equipment, properly good quality feed and water. The mastitis control measures are essentially required at dairy farm to the production of clean milk. The ultimate quality of milk and their products is determined by the complete process (from animal production to till the utilization of milk by consumers). The practices for milking ensure that milk is produced and stored under hygienic conditions and is well maintained as per the standard recommendation.
Clean Milk
Milk is mammary secretion coming from a healthy dairy animal. Hence animal health is an important aspect in the production of clean milk. It should have possessed good flavour and devoid of dirt as well as filth. It should contain relatively small number of bacterial counts which can be less than 1,00,000 standard plate count per ml of milk as well as free from pathogenic microorganisms.
Characteristics of milk
Milk is one of the safest and most balanced foods, if it is clean and wholesome. In addition to this, milk provides a favorable environment for the growth of microorganisms. The freshly drawn milk temperature is about 38°C. Bacteria multiply very rapidly in warm milk and milk spoilage is rapid if milk to be kept at this temperature. Microbes can enter milk via the cow, air, feedstuffs, milk equipments and the milker, etc. Once microorganisms get into the milk and their numbers increase rapidly. It is more effective and better to stop microorganisms to enter milk than to control microbial growth once they have entered the milk.
Steps for clean milk production
- Healthy dairy animal
- Proper housing/ nutrition
- Milking area/milk parlour
- Preparation of lactating dairy animal
- Raw milk
- Storage of milk
- Healthy dairy animal: Clean milk means raw milk, it is obtained from healthy animals. It has been produced and handled under hygienic conditions as well as it should contain very small number of harmless bacteria. Clean milk production involves a set of preventative practices that helps in keeping the animal healthy and free from diseases like mastitis, proper care and monitoring of individual animal to get the best quality milk without compromising with animal’s productivity. Maintain the cattle clean and healthy. In case animal is under treatment, discard the milk during the withdrawal period of the treatment. Do not bring the milk to milk collection centre, if the cattle are suffering from any disease. Ensure annual testing for tuberculosis and brucellosis invariably should be done. Also examine periodically for udder and other infections. Infected animals should be treated by a qualified veterinarian and should be isolated from the normal herd so as to avoid the further spread of infection.
- Proper housing and nutrition: A neat and clean housing is quite important to have healthy animal that will produce hygienic milk at farm. Optimum housing space should be provided for the proper comfort to the lactating dairy animals. Good hygiene and sanitation practices would keep it free from bacterial contamination. Clean the cattle shed floor either by washing with water or dry cleaning 10 – 15 minutes before milking. The floor should not be slippery. It should be firm and dry.
Feeding management: Always feed the animal with a high quality and nutritional valued diet, as a healthy animal will yield the cleaner milk. Feeding the animals with quality feed and fodder diets will reduce the chances of occurrence of diseases. Fresh and clean water should be at all the times in the water tubs. Clean the water tubs and the feeding manger regularly to avoid microbial growth. Never feed dusty feed concentrates which causes sneezing and coughing to the animals. To eliminate the dustiness, by offering feed either pellets or slightly moistened feed. Feeding of silage and hay during milking should be avoided. Never feed the animal spoiled feed affected with moulds or other microbes. Never allow the animal to drink dirty water as it may lead to waterborne infections. Always provide sufficient quantity of feed and drinking water to lactating animals.
- Milking area/milk parlour and milker: A milking parlor is part of a building where lactating dairy animals are milked on a dairy farm. The animals are to be milked either in housing area or milking parlour. The main advantages of a milking parlour are that it increases labor efficiency, provides good environment and reduces the risk of injury. The floor of milking area should be clean and sanitize after every milking. Parlour should be proper ventilated so that foul gases should not to be trapped inside. Parlour must be dust free environment. It is necessary to adequate lighting inside the parlour.
Milker/ Milkman: The milker should maintain proper personal hygiene. Milker should always wear neat and clean clothing and caps. They themselves should be free from communicable diseases and must be of clean habits as their clean clothes, trimmed nails, do not spit around or talk while milking. He should wash his hands before milking with detergents and drying with clean towel. He should avoid coughing and sneezing while milking.
- Preparation of lactating dairy animal: The main sources of microbial contamination are considered the mammary gland, the exterior of the udder and teats, milker’s personnel hygiene and milking equipments. Before milking the animals should be evaluated and the milk from each teat should be tested for visible defects. Regarding diseased animals (like animals with clinical mastitis) they should be segregated and milked last. The hindquarters, thighs and udder should be washed thoroughly before milking. If more hair growth is seen in the udder region, it should be clipped periodically. Buffaloes should be invariably washed before milking. The udder and teats should be cleaned always using potable water and wiped in dry cloth. After milking the udder should be washed again preferably disinfected with teat dip to avoid infection of the teats. Milk of the infected animal should never be pooled with bulk milk, until the complete animal recovers from the illness.
Milking process: Milking is an art of milker and it requires experience and skill. Milking should be done gently, quietly, quickly, cleanly and complete this process within 6-7 minutes. Lactating animals is in comfort situations produce more milk. For better udder health and producing milk that remains wholesome for longer period, complete milking has to be required. If any residual milk is left in udder, it may provide space for the growth of mastitis causing organism and affect the overall milk yield.
There are two methods of milking process
- Hand Milking: Stripping, Fisting (Knuckling), Full hand milking and Full hand milking followed by stripping. The recommended method is “full hand milking followed by stripping”.
- Machine milking: this includes hand machine milking and automatic machine milking.
- Raw milk: Microorganism grow fast on animal protein, hence raw milk is good source for the growth of pathogenic microorganism. Somatic cell counts (SCC) are indicator of mastitis and reduced milk production. Low SCC of milk ensures the quality of milk and udder health.
Somatic Cell Counts (SCC) | ||
Sr.No. | SCC increasing factors | SCC decreasing factors |
1 | Udder infection | Healthy udder |
2 | Older animals | Proper milking procedures |
3 | Improper and unhygienic milking | Teat dipping practice |
4 | Extreme climates | Complete milking |
5 | Changing feeds | Mastitis awareness |
6 | Stress | Culling of mastitic animals |
7 | Isolation of animals | Supplementation of vitamin E & Se |
Udder Health
It is necessary to get clean milk to opt certain criteria for ideal udder health. Bulk milk SSC for all lactating animals should be less than 250000 cells/ml and for first calver, it is less than 100000 cells per ml of milk. The incidence of mastitis in dairy farm should be less 25 percent in a year and whereas the culling of animals due to udder health should be less than 5 percent in a year
- Storage of milk: The place of milk collection should be maintained absolutely neat and clean to prevent any microbial contamination. Adequate facilities should be made for cleaning and sanitizing the utensils/vessels used for milk collection, storage and transport. Sanitizers having smell should not be used to clean the floor of milk room and utensils. Milk should always be kept in clean pot covered with lid. Ensure that milk cans are kept in shade or cool place before loading in the truck.
Milking utensils
The milking utensils should have small mouths to avoid external contamination. These should be preferably made up of non-rusting and non-absorbent materials (i.e. aluminium or galvanized iron or stainless steel). Stainless steel is ideal. All the utensils should be free from dents, cracks and crevices so that washing and cleaning of utensils become easier. The utensils should be scrubbed and cleaned before and after each milking. At farm, washing soda is used for cleaning of utensils followed with exposure to sunlight or use of disinfectants (iodophors) is recommended. Milking utensils or vessels should be properly cleaned vessels and placed in inverted positions for the complete drainage of water, so as to avoid contamination from air, insects and rodents, etc.
Straining and cooling of milk
Straining of milk is carried out with clean muslin cloth. Cloth should be tied on the mouth of milk collecting vessel to strain off all the extraneous matter. Straining improves the aesthetic appeal of milk for consumer. The strained milk should preferably be chilled immediately to 4oC to prevent the proliferation of pathogenic micro-organisms. Bulk can coolers are the best options where milk is stored in cans before transportation of milk. The household refrigeration is used for cooling of milk that can be consumed by family members. An effective cooling will retard the growth of mesophilic and thermophilic pathogenic microbes.
Transportation of milk
The quality of milk should be maintained during the transportation of milk from dairy farm to the consumers. A lot of changes occur during transportation which deteriorates the quality of milk. The basic system of milk transportation comprises the transport from farm to the collection centre (either in small vessels or cans), from collection centre to the chilling centre (in small tankers) and from chilling centre to the processing plant (in insulated road tankers) and from the processing plants to the retailer booths.
It is concluded that clean milk production improves the self life of milk as well as quality of milk. Clean and quality milk enhance consumers’ health benefits.
Shashi Pal and B.S. Khadda
Krishi Vigyan Kendra, S.A.S. Nagar (Mohali)