Clean Milk Production- Milk Hygiene and Udder Health: A Need for Healthy Society

Milk is defined as whole, fresh, clean lacteal secretion free from colostrums, obtained by the complete milking of healthy milch animals excluding that obtained 15 days before or 5 days after calving and containing prescribed % of fat and SNF.

Clean milk : It is lacteal secretion practically free from colostrums and extraneous material like dust, dirt, flies, hay, manure etc. Clean milk has a normal composition, possesses a natural milk flavour with free from bacterial count and is safe for human consumption.

The globalization of the food supply is recognized as a major trend contributing to food safety problems. Pathogenic micro-organisms are not contained within a single country’s borders. Additionally, tourism and increased cultural interests may lead to new eating habits, such as the consumption of ‘sushi’ (origin in Japan) or our very own tandoori tikka masala‘in Western countries. The continuous increase in international trade has been achievable partly through advances in food manufacturing and processing technologies together with improvements in transportation. Regional trade arrangements and the overall impact of the Uruguay Round Agreements have reduced many tariff and subsidy-related constraints to free trade, encouraging increased production and export from the countries with the most cost-effective production means. However, many exporting countries do not have the infrastructure to ensure high levels of hygienic food manufacture. The continuing integration and consolidation of agriculture and food industries and the globalization of food trade are changing the patterns of food production and distribution as well as supply and demand. The pressure to produce food for export is very significant in developing economics and can lead to improper agricultural practices. The consequences may include the following:

• Accidental or sporadic low level microbial contamination of a single product, which can result in a major epidemic of food-borne illness.
• high levels of mycotoxins, often resulting from poor storage and handling conditions
• high pesticides residues food
• Industrial contamination of food with metals and chemicals such as polychlorinated biphenyls (PCBs) and dioxins.

Eating away from home is a major trend of recent years. Many of the meals eaten away from home require extensive food handling and /or are cold foods that are not cooked before consumption. Subsequently this leads to the potential for transmission of food-borne diseases from food handlers to consumers. Several studies have documented an increasing lack of knowledge related to personal hygiene, the use of clean utensils and storage of food at the correct temperature. Thus, the changing trend has increased the importance that food be handled in a sanitary manner. With volume processing and preparation of food, effects of contamination are accentuated if sanitary practices are not followed. Added mechanization and larger volume operations of food processing and preparation have increased the need for workers in all segments of the food industry to have an understanding of sanitary practices and how hygienic conditions can be attained and maintained. Yet, if workers are expected to abide by these practices, it is necessary to impart a certain amount of appreciation of the reasoning behind the required practices and biological basis for the reasoning. At present, concern over food safety is at an all time high. With each food scare reported from banned dyes in multiple products to links between animal and human diseases consumer concern grows. In response, the public and the private sector have developed new process standards and require suppliers of food products to follow them. Both, the market and legislations in importing countries demand for comprehensive and transparent schemes reaching “from farm to mouth”.

The days of locally produced food being processed, distributed and consumed in the same locality have significantly decreased in recent decades. The regional, national and global food chain has required parallel changes in food science and technology, including preservation. At the same time, there have been social changes such as an increasing number of meals being consumed outside the home environment and also an ageing population. Public exposure to a food-borne pathogen may change due to changes in processing, changes in consumption patterns and the globalization of the food supply chain. Many risk factors influence host (our) susceptibility to infection. These may be:

• Pathogen (microbes)-related : ingested dose, virulence
• Host-related: age, immune status, personal hygiene, genetic susceptibility.
• Diet-related nutritional deficiencies, ingestion of fatty or highly buffered foods.

Food safety Definition:  Food Safety can be defined as the assurance that food will not cause harm to the consumer when it is prepared and or eaten according to its intended use (WHO).  All conditions and measures that are necessary during production, processing, storage, distribution and preparation of food that when ingested does not represent an appreciable risk to health.

FOOD SAFETY ISSUES

Specific food safety concerns differ markedly and include:

• Additives, colours and flavors
• Drug residues
• Fertilizers and other growing aids
• Irradiation
• Microbiological contamination
• Naturally occurring food toxicants
• Food supplements
• Pesticides
• Pollutants
• Processing ,packaging and labeling
• Adulteration and Misbranding

 Hazards associated with food:  Biological / Chemical / Physical

Macro biological

Veterinary residues, antibiotics

Glass, Hair

Microbiological

Growth stimulants

Metal

Pathogenic Bacteria

• Spore forming
• Non spore forming

Plasticizers’ and packaging migration Chemical residues, pesticides, cleaning fluids

Stones Wood Plastic Parts of pests

Parasites and protozoa/Allergens /Insulation material / Viruses / Toxic metals; Lead and cadmium

Bone / Mycotoxins

INTEGRATED APPROACH TO FOOD SAFETY The safe food production requires an all-encompassing approach involving the food operatives at the shop floor through to the management. Hence a number of management safety tools as mentioned underneath need to be implemented. Although industry and national regulators strive for production and processing systems which ensure that all food is ‘safe and wholesome’, complete freedom from risks is an unattainable goal. Safety and wholesomeness are related to a level of risk that society regards as reasonable in the context, and in comparison with other risks in everyday life. The safety of foods (especially microbiological) can be principally assured by:

1. The application of good hygienic practices during production, processing (including labeling), handling, distribution, storage, sale, preparation and use.
2. The above in conjunction with the application of the Hazard Analysis Critical Control Point (HACCP) system. This preventative system offers more control than end-product testing, because the effectiveness of microbiological examination in assessing the safety of food is limited.

 Food safety management tools (adapted from Jouve et. al 1998). Consideration of safety needs to be applied to the complete food chain, from food production on the farm, or equivalent, through to the consumer. To achieve this integration of following food safety tools is required.

• Good agriculture practices
• Good Hygienic Practice (GHP)
• Good Manufacturing Practice (GMP)
• Personnel hygiene
• Hazard Analysis Critical Control Point (HACCP)
• Microbiological Risk Assessment (MRA)
• Quality management: ISO series
• Total Quality Management (TQM)

Presents the food safety tools .These tools can be implemented worldwide, which can ease communication with food distributors and regulatory authorities especially at port of entry.

MANUFACTURE OF SAFE FOOD:  The manufacture of safe food is the responsibility of everyone in the food chain, and food factory, from the operative on the conveyor belt to the higher management. The production of safe food requires the following:

• Control at source
• Product design and process control
• Good hygienic practice during production. processing, handling and distribution, storage, sale, preparation and use
• Preventatives approach because effectiveness of microbial end-product testing is limited.

Control of food borne pathogens at source is not always easy. Many pathogens survive in the environment for long periods of time. They can be transmitted to humans by a variety of routes – water, soil, sewage, crops etc.

MILK IN HUMAN HEALTH LIFE:

Food is one of the basic needs of the human being. It is required for the normal functioning of the body parts and for a healthy growth. Food is any substance, composed of carbohydrates, water, fats and/or proteins, that is either eaten or drunk by any animal, including humans, for nutrition or pleasure. Items considered food may be sourced from plants, animals or another kingdom such as fungus. Almost all the polyunsaturated fats in the human diet are EFAs. Essential fatty acids play an important role in the life and death of cardiac cells. The use of milk and milk products as human food has got a very long history. The milk – as it is meant to be the first and sole food for offspring of mammals – is an almost complete food. It contains in a balanced form all the necessary and digestible elements for building and maintaining the human and animal body. In addition it contains immune-globulins which protect the newly born against a number of diseases. Research has shown that milk and milk products have an immune enhancing property as well, particularly for the benefit of HIV/AIDS affected people. In addition, milk contains various properties, which make it easy to convert into different milk products or to use it as an ingredient for other food items. Various human cultures have their own traditional ways of using milk and preparing different milk products.

 COMPOSITION OF MILK: Our body requires carbohydrates, proteins, fats, enzymes, vitamins and minerals for a healthy growth. However, our body cannot produce all these nutrients. Hence, food is the only source to obtain these nutrients in an adequate quantity. If we don‘t get these nutrients in sufficient amount, then we may suffer from a number of health problems. So a balanced diet is always recommended which is defined as a diet containing carbohydrate, protein, fat, dietary fibres, vitamin & minerals in right proportion. Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram differs: 4 calories in a gram of carbohydrate or protein and 9 calories in a gram of fat. These nutrients also differ in how quickly they supply energy. Carbohydrates are the quickest, and fats are the slowest. Carbohydrates, proteins, and fats are digested in the intestine, where they are broken down into their basic units: carbohydrates into sugars, proteins into amino acids, and fats into fatty acids and glycerol. The body uses these basic units to build substances it needs for growth, maintenance, and activity (including other carbohydrates, proteins, and fats).

NUTRITIONAL VALUE OF MILK: Milk is very tasteful and is an excellent source of high quality protein that can be digested easily. Milk also contains lots of important vitamins and minerals. In many countries milk and milk products provide 5 – 10 % of the total calories of the daily human diet. It represents one of the best natural sources of essential amino acids for human nutrition. Moreover, milk is an outstanding source of calcium and a good source of phosphorus. As these 2 elements play an essential role in building the bones and teeth in the body, it is clear that milk should be included in the diet of humans in all their stages of life. In fact milk is the most important source of calcium in the diet of almost all people. These nutritional attributes have made milk a mainstay in the diet, particularly of growing children. It is recommended to drink 3 – 4 glasses of milk per person per day. It is estimated that worldwide some 8,000 to 10,000 different milk products are available. This makes milk an exceptionally versatile raw product. SNF milk is known to most people as “skim milk”. SNF stands for solids-not-fat milk (SNF), which describes the total solids content minus fat. The nutritional as well as the economic value of milk is directly associated with its solids content. The higher the solids content the better its nutritional value and the more of a milk product can be made out of it. For example, cheese yields are directly related to the protein and in particular to the casein content of milk.

CHARACTERISTICS OF MILK OFF-FLAVORS:

Milk is a yellowish-white non-transparent liquid. Fresh milk has a pleasant soft and sweet taste and carries hardly any smell. Consumer acceptance of milk is greatly affected by its flavour. There are several factors which may produce off-flavours and/or odours in milk. Some of the more common causes of flavour and odour problems are:

– feed and weed flavours

– Strong smelling plants, like wild onion or garlic

– Strong flavored feedstuffs such as poor quality silage

– Cow-barn flavors from dung, etc. These are found when milk is obtained from a dirty or poorly ventilated environment or from improperly cleaned milking equipment.

– Rancid flavours. These are caused by excessive agitation of milk during collection and/or transport.

Damage of the fat globules in the milk results in the presence of free fatty acids .

– High acidity flavours

– oxidized flavours, from contact with copper or exposure to sunlight

– flavours from the use of chlorine, fly sprays, medications, etc.

Typical Milk No criticism .Very little distinct odor, pleasantly sweet and clean with no aftertaste.

Acid Basic taste sensation. Sour, tart, may cause tingling sensation on tongue. “Cultured milk” or “sour” odor may be present.

Cause – Growth of lactic acid producing organisms such as Lactococcus lactis, due to poor refrigeration, especially when temperatures exceed 70°F (21°C). “Malty” milks may be acid also.

Astringent Peculiar mouth-feel, tongue & mouth lining feel shriveled, puckered, and chalky (e.g., cranberry juice).

Cause – Associated with denatured proteins due to high heat treatments or with staleness (e.g., milk powder).May be more pronounced in skim milks and in Ultra High Temperature (UHT) or ultra-Pasteurized (UP) products. Occasionally occurs with slight rancid, bitter or acid milk.

Barny Unpleasant odor and taste of a poorly maintained barn or unpleasant feed .May be perceived as “unclean.” “Cowy” or “cow’s-breath” may present a similar defect but generally with an unpleasant medicinal or chemical (i.e., acetone) aftertaste.

Cause – absorbed, transmitted odor/flavor due to cow inhaling barn odors associated with poor ventilation and unclean barn conditions. Similar defect may be due to ketosis in cows, but with more of a medicinal or chemical after taste (see cowy).

Bitter Basic taste sensation .Pure bitter has no odor. Taste sensation is detected on the tongue after expectoration (delayed) and tends to persist. (e.g., hops in beer, coffee may be bitter)

Cause – enzymatic breakdown (microbial or milk enzymes) of milk proteins to short bitter peptides. Certain weeds ingested by cows may also cause bitterness although this is rare.

Cooked Note odor and flavor .Varies in intensity from sweet, pleasant, with slight sulfurous or custard notes, to caramelize or cabbage-like, which may be objectionable. Flavor usually becomes less intense over time but may persist depending on packaging material.

Cause – Higher pasteurization temperatures and/or longer holding times. Intensity depends on the severity of heat treatment. Cooked flavors tend to be more pronounced in batch-pasteurized than HTST milk; most pronounced in Ultra High Temperature (UHT) or Ultra Pasteurized (UP) products.

Cowy Unpleasant odor & flavor; “acetone” or “cow’s-breath”; unpleasant medicinal or chemical after taste.

Cause – metabolic disorder in cows such as acetonemia or ketosis .Rare in commingled bulk supplies. Similar defect may be transmitted/absorbed odors of poor barn conditions (i.e., barny).

Feed Odor & flavor is characteristic of associated feed; silage, hay, grassy, etc. Can be slightly sweet, generally not unpleasant, although could be unclean when strong or feed quality is poor. Most feed flavors clear up readily after milk is discharged from mouth. Common, though most often slight.

Cause – cows consume particular feed or inhale feedy odors prior to milking; transmitted to the milk. Feeding should be done after milking when practical, barns should be well ventilated.

Flat  No odor Lacks mouth-feel, flavor fullness, and/or sweetness of fresh milk  .Watery characteristic.

Cause – adulteration with water or low milk solids content. Older milk may be “flat.”

Foreign May have odor and/or flavor that is not commonly associated with milk. Often “chemical” in nature .Depends on causative agent; sanitizers, detergents, exhaust fumes, cow medications, citrus fruits, etc. Chloro-phenol compounds may give “medicinal” or “bandage-like” flavor.

Cause – Contamination of milk with foreign substance. May be direct contamination of the milk (e.g., udder ointment/chemical sanitizers, phenols/chlorine); may be transmitted through the cow or absorbed during raw storage or through retail packages in plant, store or home refrigerators.

Fruity/ Odor and flavor is usually pronounced, similar (not exact) to pineapple, apple, strawberry or other Fermented fruit (fruity); may have more of a sauerkraut or vinegar-like odor or flavor (fermented).

Cause – growth of psychrotrophic spoilage bacteria, especially certain psychrotrophic Pseudomonas species or some of the spore-forming organisms (e.g., Bacillus, Paenibacillus).

Garlic/Onion  Characteristic pungent odor and flavor .Highly objectionable.

Cause – Animals ingesting wild onion or garlic weed; may also be absorbed through packaging during refrigeration storage with onion or garlic containing foods.

Lacks- Lacks fine, pleasing flavor. Mild off-flavor that lacks specific characteristic to make identification

Freshness easy May be “stale” or less sweet (e.g., “flat”) .Generally not intense enough to fail product.

Cause – Usually due to age, staleness, residual milk enzymes or initial stage of microbial spoilage  (e.g., psychrotrophic bacterial off-flavors such as unclean, bitter and rancid).

Malty Malt-like aroma or taste (like malted milk or Grape-Nuts) .May be similar to feed or cooked odors, but is considered a severe defect as microbial spoilage. Milk often is acid as well.

Cause – Growth of Lactococcus lactis var. maltigenes (or possibly other organisms) due to poor refrigeration .May be followed by “acid” or “unclean” flavors.

Oxidized / Odor and taste of burnt-protein, burnt-feathers, or medicinal or plastic-like taste. May progress to

Light-Induced metallic or lipid oxidized type flavor due to fat oxidation.

Cause – exposure of milk to sunlight or fluorescent lights resulting in protein degradation and/or lipid oxidation. Milk in unprotected or transparent milk jugs/bottles is more susceptible although this defect may occur in paper packaging if the light is intense and exposure time is sufficient.

Metallic-Wet cardboard, oily, tallowy, chalky, or fishy flavor .Odor (old veg. oil) is pronounced when defect

Oxidized is intense .May having a lingering greasy or puckery mouth-feel .Sensation comes quickly.

Cause – milk fat oxidation catalyzed by copper or certain other metals contacting milk (e.g., copper pipe, white metal, metallic water supply) .May be associated with raw milk of cows fed high fat feeds (e.g., soybeans) and/or lack of antioxidants (e.g., vitamin E). Sometimes occurs spontaneously. Raw or cream-line milk is more susceptible than pasteurized homogenized.

Carton/ Plastic-like or wet paper flavor. Subtle, rarely pronounced unless there is evidence of carton

Paper board burning during the sealing process.

Cause – associated with paper-board packaging with heat used to seal HDPE polymer coating. Generally more apparent in half-pints due to increased package surface area to volume ratio.

Rancid Pungent odor when extreme .Taste soapy, unclean, bitter, blue cheese-like or “baby vomit.” Provolone cheese has a rancid flavor profile .Pronounced lingering after taste. Sensitivity varies.

Cause – free fatty acids (e.g., butyric acid) released from milkfat by natural or microbial enzymes (lipase). In raw milk it’s associated with excessive agitation, temperature abuse or cow factors (e.g., poor health and/or nutrition). Pasteurization destroys natural enzyme (lipase), but spoilage microorganism may have similar enzymes that cause rancidity.

Salty Basic taste sensation .No odor .Generally easily detected. Clean mouth feel.

Cause – associated with late lactation or mastitic cows .Would be rare in bulk supplies.

Unclean Unpleasant odor and taste .Mouth fails to clean up after expectorated. Suggestive of mustiness, putrid, “dirty dish-rag” or other “unclean” flavor .

Cause: Generally due to growth of spoilage microorganisms in milk or on excessively dirty equipment. Can occur due to milk absorbing odors from dirty coolers or environment .

BACTERIA IN MILK: The major group of bacteria in milk is the group of lactic acid bacteria. These are able to use the lactose in the milk and to convert it into lactic acid. The most important family in this group is the Streptococcus lactis. These multiply and grow very fast when the milk is kept at ambient temperatures after milking. The produced lactic acid causes the natural souring of milk. The primary source of these bacteria is the environment: air, dust, dirty equipment and operators, etc. How soon the milk turns sour depends on the degree of contamination and on the temperature of the milk. Therefore, proper cleaning and sanitizing procedures are essential to control the quality of milk. Cooling to a temperature of 4 ºC makes the bacteria inactive and prevents them to grow and produce the lactic acid. Once again the milk should be produced as clean as possible in the first place, but after that it should be cooled soonest. There are also types of micro-organisms which make use of other milk components, like the proteins and the milk fat. All this microbial activity deteriorates the milk quality. Therefore only fresh milk of tested quality should be used as raw material to enable processing into high quality milk products. For this reason the dairy industry strictly controls the quality of the incoming milk from the dairy farmers. If the milk quality does not fulfill the set minimum quality standards, it is rejected. This means an economical loss to the farmer. Most countries have implemented special laws and regulations concerning the composition and hygienic quality of milk and milk products to protect both the consumers and the public health. When high counts become a problem it is generally due to one or more of the following reasons:

– Improper cleaning of milking equipment (the most common cause of high bacteria counts in milk);

– Improper cooling of milk;

– Occasionally, a herd experiencing a high prevalence of bacterial infection.

Heating is another method to prevent the Streptococcus lactis to produce too much lactic acid and make the milk sour. In the dairy plant this is usually done in the form of pasteurization. During this process the milk is heated to 72 ºC for a period of 15 seconds. After pasteurization we are sure that all pathogenic bacteria, in particular the one causing tuberculosis, and at the same time most lactic acid bacteria are destroyed. When the milk is cooled after pasteurization it can be kept for approximately 5 days by the consumer without spoilage. However, certain organisms are capable of surviving pasteurization and continue to multiply during refrigeration. These bacteria are an important source of concern because they reduce the product shelf-life. To eliminate these bacteria milk can be boiled at 100 ºC or sterilized at temperatures of 120 – 140 ºC. Sterilized milk will keep its quality for a long time without cooling. However, at these high temperatures the taste of the milk is affected.

SMATIC CELLS IN MILK: Somatic cell counts represent another important milk quality parameter. The word somatic means body and thus a somatic cell is a body cell. Most important in milk are the leukocytes (white blood cells). Milk Originating from an infected udder contains a high concentration of leukocytes. Consequently, somatic cell counts are an important indicator of udder health, in particular of mastitis, Fresh milk from healthy cows has a somatic cell count of less than 200,000 cells per ml of milk. Cell counts from herd bulk milk, which are consistently in excess of 500,000 per ml, are an indication of a high prevalence of mastitis in the herd.

Milk with a high somatic cell concentration can be harmful to human health and contains less casein. This results in lower cheese yields. In addition milk with a high cell count generally contains an increased amount of enzymes, which have effect on the quality of the protein and the fat in milk. The presence of these enzymes in milk increases the potential for off flavours and odours. Because the somatic cell content of raw milk is important for the shelf-life, flavour and the yields (particularly of cheese), milk processors strive to obtain raw milk of the highest hygienic quality from their producers.

HYGIENIC QUALITY OF MILK: Milk when it emerges from a healthy udder contains only a very few bacteria. However, milk is a perishable product. It is an ideal medium for micro-organisms and as it is a liquid, it is very easily contaminated and invaded by bacteria. Almost all bacteria in milk originate from the air, dirt, dung, hairs and other extraneous substances. In other words, milk is mainly contaminated with bacteria during milking. It is possible to milk animals in such a clean way that the raw milk contains only 500 to 1,000 bacteria per ml. usually the total bacteria count after milking is up to 50,000 per ml. However, counts may reach several millions bacteria per ml. That indicates a very poor hygienic standard during milking and the handling of the milk or milk of a diseased animal with i.e, Mastitis. Raw milk is one of the most suitable media for the growth of a wide variety of bacteria. Especially immediately after milking when it is almost at body temperature. However, milk contains a natural inhibitory system which prevents a significant rise in the bacteria count during the first 2 – 3 hours. If milk is cooled within this period to 4 ˚C, it maintains nearly its original quality. Timely cooling ensures that the quality of the milk remains good for processing and consumption. The bacterial load in fresh raw milk should be less than 50,000 per ml when it reaches the collection point or processing plant. To prevent a too high multiplication of bacteria, the milk has to be produced as hygienic as possible and should be cooled or heated at the earliest. Hygienic milk only originates from mastitis free and healthy animals. Cows suffering from a disease may secrete the pathogenic bacteria, which cause their disease, in the milk they produce. Consumption of raw milk therefore might be dangerous to the consumer. Some of these diseases, like tuberculosis, brucellosis and anthrax, can be transmitted to the consumer. Whatever the milk is used for during processing, the hygienic standard of the produced milk at farm level forms the basis of the quality of the ultimate milk products.

MONITORING MILK QUALITY AT THE MILK COLLECTION CENTER:  The function of the milk analyzer is to make quick analyses of the milk at the MCC on fat, solids-non-fat (SNF), lactose, added water, temperature, pH and freezing point. This instrument is quite delicate and has to be used very carefully and cautiously to monitor the milk quality or in cases of doubt of adulteration or any other fraud. The lacto scan has to be installed at a fixed place on a table and frequent movement is to be avoided. It is suggested to test not more than 25 samples in a day. The composite testing of the bulk sample should be done every week and be recorded to monitor the quality. The instrument must be cleaned after every day use as per manufacturer specifications.

ECONOMICS OF CLEAN MILK PRODUCTION: When setting standards for clean milk production, it is important that the standards reflect the local conditions. If consumers boil the milk before use and if it is consumed within hours of production, high capital investments to improve hygiene may not be an economic necessity. With an increasing time between milking and consumption, hygienic measures become more important and should intensify. At the same time, with an increasing scale of farming, there is more room for investments in hygienic practices. The cost of clean milk production should not exceed the benefit for the farmers. Milk payments should be an incentive to improve the hygiene, and clean milk production should be financially rewarded. Fortunately that happens in Zambia, since Parmalat pays the farmers on basis of the bacterial status of the milk.

ECONOMICS OF CLEAN MILK PRODUCTION: When setting standards for clean milk production, it is important that the standards reflect the local conditions. If consumers boil the milk before use and if it is consumed within hours of production, high capital investments to improve hygiene may not be an economic necessity. With an increasing time between milking and consumption, hygienic measures become more important and should intensify. At the same time, with an increasing scale of farming, there is more room for investments in hygienic practices. The cost of clean milk production should not exceed the benefit for the farmers. Milk payments should be an incentive to improve the hygiene, and clean milk production should be financially rewarded. Fortunately that happens in Zambia, since Parmalat pays the farmers on basis of the bacterial status of the milk.

THE PRODUCTION OF QUALITY MILK: WHO’S CONCERN

From history records we know that cows have been milked as far back as 9000 B.C. Most cattle were multi-purpose animals. They were kept to satisfy the family needs of food (milk and meat) and to provide draught power and manure. In those times milk had to be consumed immediately because it could not be stored. Moreover, milk production was seasonal, creating both periods of excess and of deficiency in the family milk supply. To stabilize these production fluctuations and to enable storage, further processing into butter, cheese, or other milk products were invented and developed. Later, this processing allowed marketing of milk, butter and cheese to towns as well. Over the years modern technology has been developed and today a wide array of safe, wholesome dairy products are available to people. Production of quality milk is a complicated process.

It is the concern of so many stakeholders, which include:

– Dairy farmers;

– Dairy cooperatives;

– Milk and milk product processors;

– Retail distributors (shopkeepers and super markets);

– Consumers of dairy products;

– State regulatory departments;

– Extension staff and veterinarians.

From the list it is obvious that very few of us are left out. Whether we derive a living from the dairy industry through employment or otherwise, most of us are at the very least consumers of dairy products .In the sections to follow we will examine the efforts made in the processing of dairy products (from the farm to the retail shelf) to preserve the public’s confidence and safety and to remain in dairy business.

MILK CHAIN SYSTEM: The efficient production of milk under good hygienic conditions is the key to successful dairying. The principal constraint in particularly smallholder systems is a high level of bacterial contamination in the milk. This might lead to its spoilage before it reaches the market. The first step for a farmer is to produce good quality milk from healthy (non-mastitis) cows. It is important that farmers are given advice and assistance on how to produce clean milk. This is the basis which enables successful collection and marketing of the milk. In the first place attention should be paid to the equipment used. This has to be suitable for effective cleaning and sanitization. In the second place emphasis should be given to good hygienic practices during milking. Finally, attention has to be paid to the transport and collection of the surplus milk to the point of sale or processing. Collection and transport of the milk should not take very long to minimize post harvest spoilage.

 IMPORTANCE OF SAFE FOOD: A safe food supply that will not endanger consumer health and good quality food is essential for proper nutrition. It would ensure prevention of food borne diseases, provide consumer unadulterated food of good quality. It also promotes participation in International trade in food products and stimulates economic development. Maintaining food safety and quality is essential in the entire chain of food production ranging from i) primary food production at the level of farmers; ii) secondary food processing level such as canning, freezing, drying and brewing; iii) food distribution, both at National and International level of import/export; v) Food retailing and Food catering and also vi) Domestic Food preparation level. During recent years, newer challenges such as globalization of trade in food, urbanization, changes in life style, international travel, environmental pollution, deliberate adulteration and natural and man-made disasters have arisen which need to be addressed to help ensure food safety and quality. For example, greater numbers of people go out and eat meals in catering establishments including partaking street foods. The boom in food service establishments is not matched by effective food safety education and control. Unhygienic preparation of food provides plenty of opportunity for contamination, growth or survival of food borne pathogens. Also in the developed countries, a considerable public interest has been shown with regard to genetically modified foods, and the possible risk of transmission of mad cow disease through the consumption of beef. Consumer confidence in the safety and quality of the food supply is an important requirement and consumers are demanding protection for the whole food supply chain from primary producer to the end consumer, often described as from farm or pond to the plate approach. It is absolutely essential for countries to protect the safety and quality of their foods entering international trade. Also it is necessary to ensure that imported foods are of good quality and safe to eat. The new world order and global environment for food trade places considerable obligation on the part of both importing and exporting countries to ensure safety and quality of food. The International agencies like Food and Agriculture Organization and World Health Organization as well as the Codex Alimentarius Commission, with a membership of 165 countries, recommends risk analysis approach which includes risk assessment, risk management and risk communication. The perception of what constitutes a risk depends on a person‘s culture, education and past experience. But while what is perceived as a risk may differ, the basic scientific principles for dealing with risk are the same. Education and Training plays an important role in improving the safety and quality of food. It is essential to acquire the know-how and skills necessary to understand and manage food safety hazards. Both education and training are needed for the purpose. While education aims at influencing the way of life and empowering people to make a choice, training is a process by which one is enable to acquire a skill. Any successful food safety programme will always need a shared responsibility among producers, industry, trade, government and the consumer.

 MILK QUALITY AND HYGIENE AT PRIMARY LEVEL

THE CONCEPT OF CLEAN MILK PRODUCTION: Micro-organisms are found everywhere: on animals and people, in the air, the soil, in water and in milk. Good sanitary practices throughout the entire milk chain, from milking through processing to packaging, result in safe milk of a good quality. The main sources of contamination by microorganisms in raw milk are the surfaces which it contacts. These include the udder, the hands of the milker and the utensils. This means that it is very important to clean hands and surfaces carefully with clean water. Improving sanitary practices during traditional milk handling and processing may meet resistance from farmers. Therefore training of a practical nature is needed. Once micro-organisms have found their way into milk, they develop easily and multiply rapidly. Microorganisms grow best at room temperature, so keeping milk cool will slow down their growth. Heating the milk, like pasteurization, destroys a large number of microorganisms. Increasing the acidity of the milk by fermentation suppresses the growth of harmful organisms as well. The term clean milk means raw milk from healthy animals that has been produced and handled under hygienic conditions. It is free from extraneous matters like dust, dirt, flies, manure, etc. Clean milk has a normal composition, possesses a natural milk flavour, contains only a small number of harmless bacteria, is free from hazardous chemical residues and safe for human consumption. The status of raw milk is determined by its bacterial quality and the somatic cell count. With simple and low-cost husbandry practices it is possible to produce milk with a count of less than 50,000 bacteria per ml. The golden rule of clean milk production is that prevention is better than cure. In summary clean milk production results in milk that:

– is safe for human consumption and free from disease producing microorganisms;

– has a high keeping quality;

– has a high commercial value;

– can be transported over long distances.

The safe handling of raw milk is based universally on the following two principles:

– avoid or minimize contamination at the various stages of handling raw milk;

– reduce the growth and activity of the micro-organisms in raw milk.

The unhygienic and undesirable practices that decrease the quality of raw milk can be classified into three categories:

Practices related to the animal:  Animals are not healthy or suffer from mastitis;

– Animals are dirty, in particular the udder, the teats, the hind quarter and the tail.

Practices at milking:  Hands and clothes of the milker are not clean and he or she practices unhygienic personal habits.

Practices related to the milking process:  Wrong milking procedures (like stripping) are used; the utensils and the milk can are not cleaned properly.

 CONTAMINATION AND CONTROL MEASURES AT FARM LEVEL: On the farm contamination of milk can occur at the following places and procedures:

– Animal shed and environment.

– The animal

– Milker and milking routine

– Milking equipment

– Storage and transport

 Animal shed and environment: The environment in and around the milking premises determine to a great extend the level of contamination of the milk. If milking is done inside a shed, as is usually the case with smallholder farmers, there is a high risk of contamination through the air and by insects, in particular flies. The shed should provide protection against wind, rain and excessive heat, but at the same time have sufficient light and ventilation. The milking area of the shed needs special hygienic attention. The floor of the milking place should be made of concrete so that mud, urine, faeces and feed residues can be removed. It should be swept with clean water before and after each milking. For that reason the shed should be located on a higher place to facilitate proper drainage. Facilities should be created for an adequate and sufficient supply of safe and potable water. In case all these conditions cannot be met, milking in the pasture or a clean open field is preferable to milking in a dirty and/or muddy stable or kraal.

The animal: The animal itself is an important source of contamination. Care and management of the animal and its health is therefore the starting point for clean milk production. The skin of the animal provides a large surface for possible contamination. Dung, urine, uterine discharge, dirt, dust and hairs can pass millions of bacteria, when it drops from the skin and udder into the milk. Long hairs on the flanks, hind legs, tail and udder should be clipped at frequent intervals. Grooming the animals regularly can help to keep hair and dust away from milk. When cows are kept indoors or graze in heavily stocked paddocks, the udder will be grossly contaminated with bacteria, even when it appears visibly clean. If the animal is suffering from infections such as mastitis, the milk will contain harmful pathogenic micro-organisms. Milk from diseased animals should be kept separate and disposed of safely. Routine control on mastitis can reduce the proportion of infected cows. It is advisable to test the foremilk at each milking with a strip cup.

Milker and milking routine: In case of hand milking, the danger of contamination coming from the milker is higher as compared to machine milking. As the milker moves from one animal to the next, he/she can transfer pathogenic micro-organisms to all the animals in the herd. In this way the milk can become contaminated as well, making it unsafe for human consumption. Therefore the milker should be free from contagious diseases. The milker should wear clean clothes and have trimmed and clean nails. He/she should wash hands with soap and water before milking and dry them with a clean towel. The milker should always cough or sneeze away from the milking pail.

A good milking routine prevents contamination of the milk. Consistent milking at regular intervals using a fast but gentle technique, which empties the udder completely, are important aspects.  Feeding roughage at the time of milking should be avoided, as dust and/ or smell easily contaminates the milk. If calves are suckling, the calf should be allowed to suckle at the beginning of the milking. The udder and teats should be washed and massaged for at least 30 seconds using clean water and a cloth or individual paper towels. It is advisable to add a dash (about 15 ml) disinfectant (sodium hypochlorite) to a bucket of water. If udder cloths are used, rinse them regularly in between milking different cows. After each milking wash and disinfect the cloth and hang it to dry. Disposable paper towels are preferable and more effective for drying the udder after washing.  Foremilk should be examined and abnormal milk should be discarded. The foremilk should not be allowed to run on the floor as this increases the danger of contamination. During milking all milk should be drawn directly into the pail as fast as possible. The milker should not wipe his/her hands on the body of the animals or on his/her own body. After milking, the teats can be dipped or sprayed with a gentle antiseptic solution. Filtering or straining the milk removes visible dirt but not the bacteria from the milk. Bacteria will pass through the filter. Cloth filters must be properly washed and dried in the sun after each use.

Milking equipment:   All dairy utensils such as buckets, milking cans and filters should be thoroughly cleaned immediately after use. Any milk residues on the equipment will allow microorganisms to grow rapidly. Also ancillary equipment, including foremilk cups and udder cloths, must be cleaned and disinfected effectively.

Cleaning and disinfection: First wash the utensils with hot water and a detergent. A clean brush with good bristles should be used, which is only designated for the cleaning of the milk equipment. Then rinse with clean water. After that the equipment has to be disinfected with either hot water or with a disinfectant, like hypochlorite. Do not dry the utensils with a piece of cloth, but drain them immediately after washing. Bacteria will not multiply in dry conditions but water lodged in milking equipment will, in the prevailing temperatures, provide conditions for massive bacterial growth. To facilitate drainage of wash water put the utensils in an inverted position on a drying rack, preferably in the sun. At the farm it is virtually impossible to remove all milk residues and deposits from the milking equipment. Bacteria will multiply on these surfaces during the interval between milking, so that high numbers can be present on visually clean equipment. Therefore, the equipment should be rinsed about 15 minutes before milking with a disinfectant.

Equipment: The utensils and equipment used during milking should be made of non-absorbent, corrosion-resistant material. The surface should be smooth, have minimal joints or open seams and should be free from dents. Although expensive, by far the best option is stainless steel. Plastic is not advisable as after some time the surface will contain scratches, which can hardly be seen but are nearly impossible to clean. For the same reason in case of machine milking the rubber components have to be renewed at regular intervals.

 Water supply: A clean water supply is essential to minimize contamination. Unless an approved piped supply is available, it must be assumed that water is contaminated. Some water borne bacteria are dangerous and can easily enter the milk. Examples are the Coli forms, which cause stomach disorders and cholera and may even lead to death. Therefore the cleaning water must be boiled or hypochlorite must be added at about 15 ml per 10 liters water. Alternatively, the quality can be improved by adding one drop household bleach to one liter of water. Hard water (i.e. high levels of dissolved calcium and other salts) will cause surface deposits on the equipment and reduce cleaning effectiveness. In such cases, it is necessary to use de-scaling solutions periodically.

Detergents and disinfectants: Detergents are necessary to clean milking equipment effectively before disinfection. The effectiveness is increased when warm water is used. This helps to displace milk deposits and to remove dirt, dissolve milk protein and emulsify the fat. Make sure that the correct concentration is used. Many detergents are available in the market, but if not, an inexpensive mixture can be made by using a solution of soda, teepol or even washing powder. About 1 teaspoon per litre water gives the correct concentration. Disinfectants are required to destroy the bacteria remaining after washing and to prevent these subsequently from multiplying on the cleaned surfaces. Also their effectiveness is increased with temperature. Sufficient contact time should be allowed with the surfaces to be cleaned and disinfected. When hot water is used, it is best to begin the routine with water at not less than 85°C. Many chemicals are suitable as a disinfectant. Some of them are combined with detergents (i.e. detergent-sterilizers). Use those which are approved only, as some can taint milk. Always follow the manufacturer’s instructions!! Sodium hypochlorite is an inexpensive disinfectant suitable for most dairy purposes. Sodium hydroxide (caustic soda) can also be very effective at concentrations of 3 – 5 %.  Dairy disinfectants are sold as concentrated solutions. In this form they are often corrosive and damaging to the skin and eyes. They should always be clearly labeled, handled with care and stored out of the reach of children. Disinfectants should not be mixed unless specific instructions are given. Disinfectant powders must be kept dry. If any concentrated detergent or disinfectant comes in contact with the skin or eyes, the affected area should be washed immediately with copious amounts of clean water. If acids are used they must always be added to the water and NOT vice versa.

The following detergents can be used for dairy cleaning:

– Sodium Hydroxide

– Teepol

– Surf powder

-Washing soda etc

 Storage and transport: Milk should be stored in clean containers with a lid and kept in a cool and shady place where the danger of contamination is minimal. Transport should take place in clean containers as well. It is important to keep the transport time to a minimum and avoid violent movement of the milk. Heat, light and violent movement can all cause breakdown of certain components in the milk and affect its taste. Milk must reach the Milk Collection Centre quickly, ideally within 2 – 3 hours after milking. Preferably, the milk is cooled to 4 ºC at the MCC and kept at that temperature until it is processed. In case chilling is not feasible, preservatives like lacto-peroxides’ can be added to prolong the time before the milk gets spoiled. However, this procedure is not yet allowed in several countries, like Zambia.

HYGIENIC AND GOOD MILKING PRACTICES

– Have clean milking utensils ready before the start of milking.

– Tie up the cow in the milking shed and give it some concentrate.

– Always use clean milking utensils, clean your hands and make sure your nails are short.

– Clean the udder and check the foremilk for any clots or pus signifying mastitis. Milk any sick cow or cow with mastitis the last.

– The first few drops of milk should be discarded as these contain a large number of bacteria.

– The foremilk should be collected in a cup or utensil and not thrown on the floor, where it will contract flies and other insects.

– Milk quickly and evenly with as little pulling as possible, preferably by squeezing the teats.

– Milking should be complete, with no visible milk left in the udder.

– Milking should be done with full hands, quickly and completely. Milking a cow should be completed in 7 – 8 minutes.

– Unhygienic practices such as dipping the fingers in the milk and then wetting the teats to soften them should not be permitted.

– Milking with full hands and not with the knuckles is preferred as the latter leads to more chances of teat injury.

– Post milking dipping of each teat should be routine.

– Clean all milking utensils immediately after milking and leave them ready for the next milking.

– Therapy with antibiotics at the time a cow is dried off can be done in case of a high mastitis rate in the herd.

 MASTITIS, CONTROL AND PREVENTION

What is mastitis?

Mastitis is the biggest enemy of a dairy farmer whether small or big. It reduces both the productivity of the cow and the quality of the milk. Mastitis is very common. At any given time it is estimated that approximately 17 – 20 % of the total dairy cow population suffers from mastitis. Mastitis is a disease characterized by inflammation of the udder and is caused by bacteria.

 The most important effects of mastitis on dairy farming:

– Reduced milk yield per cow;

– Deleterious effects on the composition of milk and consequently its rejection by processor and consumer;

– Presence of bacteria and other infectious agents which may be harmful to human health, but also to the calf;

– Mastitis therapy results in the presence of antibiotic residues in milk, rendering it unsuitable for human consumption or further dairy processing;

– Animals suffer from the disease and may even die. Often one or more quarters or even the whole udder may become permanently dysfunctional.

It is impossible to prevent mastitis infection entirely, but by adopting practical routines it can be kept at low levels. The control of mastitis includes effective hygiene before, during and after milking, efficient dry cow therapy and detection of both clinical and sub-clinical mastitis at an early stage. Most mastitis is subclinical and not readily detected by the milker. Normally the bacterial count of herd milk is not affected and will remain below 50,000 per ml. Once the clinical stage is reached, the count may increase to several millions per ml and one infected quarter may make the milk of the whole herd unacceptable. The public health implications are that consumption of milk from a cow having mastitis may lead to diseases and food poisoning. FIGURE 18: A cow with an initial stage of mastitis in one quarter

Causes of mastitis: The risk of mastitis is the highest in early lactation and in high producing cows. It increases with the age of the cow. Factors which predispose to mastitis include poor hygiene, poor animal husbandry and malfunction of milking machines. Wrong methods of both hand and machine milking may damage the teat or udder, allowing micro organisms’ easier access to the udder through the teat canal.

Mastitis development: The initial inflammatory reaction is followed by the release of substances causing fever and swelling of the udder. The swollen quarters of the udder become hot, red and painful. The bacteria start multiplying inside the udder at a very fast rate.

Types of mastitis:

Sub-clinical mastitis: Sub-clinical mastitis is the most common. It cannot be observed easily on physical examination of the udder. Also there are no visible changes in the milk. Gradual decline in milk production is a characteristic feature of sub-clinical mastitis. The milk has a normal or slightly increased somatic cell count. Since it is not recognized this mastitis is economically the most harmful one. It is estimated that 50% of all cows have subclinical mastitis in one quarter of their udder.

Clinical mastitis: Clinical mastitis is characterized by the presence of an inflammatory reaction in the udder. It is usually accompanied by a mild fever and the animal is depressed. The milk is abnormal and the affected quarter is sensitive to touch and painful to the animal. The milk yield is reduced. When the acute mastitis is not attended and the inflammatory process persists for many months, the mastitis becomes chronic. At this stage a progressive fibrosis (hardness) is found in the gland, caused by tissue what is not able to secret milk any more. These changes are generally permanent and are not curable.

 Diagnosis: Several simple tests can be performed on the farm at the side of the cow to diagnose mastitis. Clinical mastitis may be detected by examining the udder for warmth or hotness, swollen quarters and pain. Misshapen, hard and fibrotic quarters indicate damage caused by chronic mastitis. The strip cup test is a practical and effective method of identifying cows with clinical mastitis. A few drops of the foremilk of each teat are milked into a strip cup or on a plate with a black surface. In chronic mastitis the milk is not always seen abnormal. The strip cup test is sufficiently sensitive to detect clinical mastitis by an experienced milker. When a strip cup is used it should be cleaned and disinfected after every milking. Foremilk samples should not be mixed with the other milk of the cow, because of a high bacteria count. The California Mastitis Test (CMT) is another cow side test that can be used for the detection of mastitis. It is more sensitive than the strip cup test and enables sub-clinical mastitis to be detected. For reliable results the CMT should be conducted just before milking, after stimulating the cow and having discarded the foremilk. A four-cup plastic paddle is used and some milk from each quarter is drawn into a separate cup. A half teaspoon Teepol or Mastest is added to each cup and the paddle is rotated to mix the milk with the reagent. Normal milk remains fluid and flows freely. Gel formation is a detection of sub-clinical mastitis or milk with increased somatic cells.

 Control: Mastitis not only reduces the productive capacity of the cows, it is also expensive to treat. Therefore its prevention should be the prime concern of each farmer. Improved animal husbandry, hygiene and good management are the only practical methods of prevention and disease control. Cows suffering from mastitis may recover spontaneously, but usually drug therapy is required to maintain productivity. It is a good practice to empty the effected quarters as often as possible by stripping the concerned teats several times per day. To prevent cows from damaging their teats barbed wires should be removed from the premises.

Treatment: As treatment an antibiotic must reach the causative bacteria in the udder. Therefore an intra-mammary treatment is by far the most common method for all forms of mastitis. The antibiotic must be administered into the teat of the affected quarter after this has been emptied of milk. The drug manufacturer’s instructions regarding frequency, duration and level of treatment should be followed exactly. Udder balm may be applied on the udder to reduce inflammation.

Hygiene and management: The infection easily spreads from one cow to the other. This may occur during milking via contaminated milk, the hands of the milker, udder cloths and in case of machine milking the teat cup liners. Infection may also occur during the interval between milking. Possible routes are contaminated beddings, licking of teats and udder, contact of the udder with the tail and legs and flies. Therefore strict hygiene has to be maintained. Cows with a high cell count can be separated from healthy cows with a low cell count. Disinfection of the entire teats immediately after milking in a safe and effective teat dip is perhaps the most important single measure a dairy farmer can apply to reduce new infections in a herd. Most commercially available teat dips will reduce new infections by at least 50 %. In conclusion the most effective measures to prevent mastitis are:

– maintaining a consistent high standard of management and hygiene before, during and after milking;

– using a good milking technique or an adequately functioning milking machine;

– using of teat-dip with a disinfectant on all cows after every milking;

– treating all cows with evidence of clinical mastitis promptly;

– applying the somatic cell count monthly to monitor the health status of the herd;

– applying antibiotics to all cows after the last milking at the time they are dried off;

– attending immediately to any minor injury to the teat or udder tissue;

– culling of cows suffering from recurrent clinical mastitis.

 ANTIBIOTIC RESIDUES IN MILK: Antibiotic residues pose a significant public health threat. Moreover, it makes the processing of milk into cultured sour products, like yoghurt, and the manufacture of cheese impossible. This causes an enormous economic loss to the milk processor. Consequently, milk in many countries is routinely monitored on antibiotics. Although the vast majority of antibiotic residues in milk occur by accident, farmers are fined for considerable amounts of money if their milk is found to contain antibiotics. Veterinarians advise farmers not to use milk of cows which have received an antibiotic treatment during 3 days after the treatment was stopped. During that period the milk should definitely not be delivered to the Milk Collection Centre and/or the processor.

Farmers can avoid residue problems by:

– identifying cows treated with antibiotics properly;

– informing milkers of the need to withhold milk from delivery;

– keeping an accurate record of dates and times of treatment;

– following label directions and veterinarians’ advice for withholding periods;

– having milk tested from suspect cows if uncertainty about treatment or withholding time exists.

 FARMERS SUPPORT SERVICES:  Milk Producers Organizations like dairy cooperatives should provide ‘support-services’ for their farmers. This will assist the farmers to increase their production of high quality milk. Support services could include the following activities.

 Farm inputs: The farmers group can open a store with farm inputs like concentrates, milking equipment and axillaries, veterinary drugs and implements, seeds, fertilizer and general items like wire, etc. These items are often not available far out in the rural areas, so that farmers have to travel long distances to purchase them and pay a high price to transport them home. The group can provide the inputs on credit and deduct the purchase price from the next milk payment. When farmers have easy access to these inputs, they can improve the management of their animals and increase the quantity of milk they produce.

 Artificial Insemination: The farmers group can also consider making Artificial Insemination available for their members. The group can buy a container and the necessary equipment. If legislation permits it can be considered to train one of the group members, who is interested, to carry out all the required inseminations. Another possibility is to give this task to an extension worker, whom the group employs.

Extension service: If the group is financially strong enough, it should consider seriously employing an extension worker .Unless this service is provided adequately by the Government or other organizations. In any case the availability of extension staff to give advice to farmers is of crucial importance. All management aspects like growing adequate fodder, feeding, fertility, calf rearing, housing, etc. should receive attention. But also aspects, like proper milking techniques, hygienic handling and cooling of milk should receive attention, since knowledge on these aspects is often lacking with farmers. Extension officers can organize group activities like discussions and instructions for all members of the group, field days at farms of different members and they can pay individual visits to farmers. At the same time he/she can collect data from the farms and assist farmers to keep records of their activities and results. Extension and education should go hand in hand to develop awareness and knowledge amongst the milk producers and should focus in particular on the empowerment of the real workers involved in milk handling and production.

 Veterinary services: An effective and well trained animal health service should be available at all times to look after the health of animals. Arrangements should be made for regular vaccination and checking against contagious diseases. Veterinary first aid should be readily available around the clock at village level. These services should be organized at village or cooperative level on regular basis.

Costs: The group should agree and decide how to pay for the dairy support services the group is going to introduce. It could be considered to start a ’Dairy Development Fund‘. To finance this fund the milk price for the farmers is lowered by for example 10%. In return the farmers receive the services they require from this Development Fund. These services can include training, buying animal feed, artificial insemination or any other dairy support activity. Money can be reserved to replace transport and dairy equipment as well.

MILK QUALITY AND HYGIENE AT PROCESSING LEVEL

MILK PROCESSORS OBJECTIVES: Food processing is the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans either in the home or by the food processing industry. Food processing typically takes clean, harvested crops or slaughtered and butchered animal products and uses these to produce attractive, marketable and often long shelf-life food products. All these methods are used by food processing industry to give out processed or preserved foods for our daily consumption. Best quality harvested, slaughtered and butchered and clean constituents are used by food processing industry to manufacture very nutritious and easy to cook food products.

 A multitude of events take place in the process of delivering milk from the farm to the dinner table. All are designed to provide the consumer with a wholesome, nutritious and safe product. The production of quality milk and milk products begins at the farm and continues through further handling, processing and distribution.

Milk processing has three primary objectives:

– Destruction of pathogenic bacteria through pasteurization or boiling;

– keeping the quality of the product without significant loss of flavor, appearance, physical and nutritive properties;

– Selective control of organisms which may produce unsatisfactory products.

  Milk Processing: To ensure safe milk free from disease-producing bacteria, toxic substances and foreign flavors, fresh whole milk is to be processed before marketing. The processing helps produce milk that has an initial low bacterial count, good flavor and satisfactory keeping qualities. Milk processing operations consist of clarification, pasteurization and homogenization. The flow chart for the manufacture, packaging and storage of pasteurized milk is as follows: Raw milk

Receiving milk (grading, sampling, weighing, testing)

Preheating (35 -40°C)

Pre-filtration/Clarification

Cooling and storage (5°C or below)

Standardization

Homogenization I (2000 psi/60°C)

Homogenization II (500 psi/60°C) Pasteurization (63°C/30min or 72°C/15 sec)

Packaging

Storage (5°C or below)

Clarification Noticeable quantities of foreign materials such as particles of dust, dirt and many other undesirable substances find their way into milk due to careless handling. To remove these, milk is generally passed through a centrifugal clarifier. The speed of the clarifier will be such that there is little separation of cream. This operation removes all dirt, filth, cells from the udder and some bacteria. Clarification does not remove all pathogenic bacteria from milk.

Filtration removes suspended foreign particles by the straining process, while clarification is by centrifugal sedimentation. Standardisation is the adjustment of fat and /or SNF by increasing or decreasing.

Homogenization The process of making a stable emulsion of milk fat and milk serum by mechanical treatment and rendering the mixture homogenous is homogenization. This is achieved by passing warm milk or cream through a small aperture under high pressure and velocity. High-pressure homogenizers, low-pressure rotary type homogenizers and sonic vibrators are used for the purpose. The fat globules have a tendency to gather into clumps and rise due to their lower density than skim milk. When milk is homogenized the average size of the globule will be about 2 μm. Homogenized milk has a creamier structure, bland flavor and a whiter appearance.

Pasteurization The aim of pasteurization of milk is to get rid of any disease-producing bacteria it may contain and to reduce substantially the total bacterial count for improved keeping qualities. Current recommendations for pasteurization are based on low temperature-long-time (LTLT) method of holding at 63°C for 30 min to eliminate pathogenic bacteria that may be present such as Mycobacterium tuberculosis and Coxiella burnett. The index organism for pasteurization is taken as Mycobacterium tuberculosis. In high temperature short time pasteurization (HTST), milk is heated to 72°C for 15 sec. In ultrahigh temperature (UHT) pasteurization milk and milk product they are heated to at least 138°C for 2 sec and packaged aseptically. As pasteurized milk is not sterile it must be quickly cooled after pasteurization to prevent multiplication of surviving bacteria. The effectiveness of pasteurisation is evaluated by phosphatase test (alkaline phosphatase activity in milk).

Milk processing plant procedures seek to:

– prevent further bacterial contamination of raw materials;

– reduce bacterial numbers in milk;

– protect the finished product from recontamination through careful handling, proper packaging and storage.

Pasteurization makes raw milk safe for human consumption. It is the process of heating milk to a sufficient temperature (72ºC) for a sufficient length of time (15 seconds) to destroy all pathogens. However, the milk will not become totally free of all bacteria.

All dairy manufacturers have Product Recall systems.

Milk

Ingredients

Packing material

Equipment

Cleaning

Skilled staff

Traceability

Documented HACCP based food safety plans and quality assurance programs are developed to ensure that consumer needs and specifications, including food safety, are constantly met.

The core elements of the FSP for manufacturing establishments include:

• Pathogen reduction technologies including pasteurisation
• Temperature controls
• processing
• Cleaning and sanitizing
• Storage
• Traceability forwards and backwards through the supply chain from farm to customer
• Post-pasteurisation hazard management
• Raw material and ingredient management
• Records and
• Personnel competency

MILK QUALITY CONTROL: Milk testing and quality control is an essential component of any milk processing industry whether small, medium or large scale. Milk being made up of 87% water is prone to adulteration by unscrupulous middlemen and unfaithful farm workers. Moreover, its high nutritive value makes it an ideal medium for the rapid multiplication of bacteria, particularly when it is produced under unhygienic conditions and stored at ambient temperatures. In order for any processor to make good dairy products, good quality raw materials are essential. A milk processor or handler will only be assured of the quality of raw milk if certain basic quality tests are carried out at various stages of milk handling from the producer to the processor.

Milk testing for quality can be divided into testing for hygiene and for composition. The methods used for milk testing are usually related to the payment system adopted. One always has to balance between the costs and the benefits of the tests. It should be realized that testing all the milk regularly can become very expensive!

What is milk quality control?

Milk quality control is the use of approved tests to ensure the application of approved practices, standards and regulations concerning the milk and milk products. The tests are designed to ensure that milk products meet set standards for composition and purity as well as accepted levels of different micro-organisms and somatic cells.

Why to have quality control?

Under quality control we test milk and milk products for quality and we monitor that milk producer, processors and marketing agencies adhere to accepted codes of practices. A system of quality control is expensive and costs lots of money. So there must be good reasons why we need a quality control system for the dairy industry. For the different stakeholders in the milk chain these are the following:

l) To the milk producer

The milk producer expects a fair price in accordance with the quality of milk she/he produces.

ll) To the milk processor.

The milk processor who pays the producer must assure him / her that the milk received for processing is of normal composition and is suitable for processing into various dairy products.

lll) To the consumer

The consumer expects to pay a fair price for milk and milk products, which are safe and of acceptable to excellent quality.

lV) To the public and government agencies

These have to ensure that the health and nutritional status of the people is protected from the consumption of contaminated and sub-standard foodstuffs and that prices paid are fair to the milk producers, the milk processor and to the final consumer. All the above is only possible through the institution of a workable quality testing and assurance system conform to national or internationally acceptable standards.

Quality control in the milk marketing chain

Quality control in the dairy industry must cover all the quality aspects of milk and milk products throughout the total milk chain from the dairy cow to the consumer. Quality control includes the following aspects:

l) At the dairy farm

Quality control and assurance must begin at the farm. Farmers must use approved practices of milk production and handling. Also all regulations regarding the use of veterinary drugs on lactating animals and against adulteration of milk, etc. must be observed.

(ll) At Milk Collection Centers

All milk from different farmers must be checked for quantity, wholesomeness, acidity and hygienic quality.

(lll) At reception in dairy factories

Milk from individual farmers or bulked milk from various Milk Collection Centers must be checked for quantity plus bacteriological and compositional quality. Also tests on the presence of antibiotics are carried out regularly.

 (lV) Within the dairy factory

Once the dairy factory has accepted the farmer’s milk it has the responsibility to ensure that the milk is handled hygienically during processing. At the dairy plant quality assurance tests must be carried out to ensure that the products are processed conform specified standards. These relate to the adequacy of the processes applied and to the keeping quality of the manufactured products.

(V) During marketing of processed products

Public Health authorities are employed by law to check the quality of food stuffs sold for public consumption. Their inspectors may impound substandard or contaminated foodstuffs and prosecute possible culprits.

 Commitment of quality Customer and consumer expectations continually enhanced through prevention, measurement and improvement initiatives; we stand for uncompromising standards of quality, safety and integrity. From Dairy Farmer to up to the market is Quality our responsibility in every step of the Quality System ensures in consistent frame work to deliver of quality products and services to our customers.

How does supply management benefit producers and consumers?

For producers

1. The receive a fair price for milk
2. Earn enough to cover the costs of the average dairy farm
3. Do not rely on government subsidies or taxpayer dollars to make a living
4. Transportation costs are minimized because of a centrally planned transportation route from farm to processing facility
5. Stable incomes mean that investments can be made in long-term housing and equipment to take care of the animals in the best way possible
6. Smaller farms can be more profitable than they would be without supply-management

 Farmer can improve milk quality:

1. Check the milking system twice a year for problems
2. Sanitize milking equipment before and after each milking
3. Follow proper milking procedures
4. Prevent inhibitors by keeping detailed records of when cows are treated, what drug they are treated with and when their milk can go back into the bulk tank
5. Reduce high somatic cell counts by developing a comprehensive mastitis control program
6. Keep the barn and the cows inside it clean and neat Milk is typically picked up at the farm every other day, ensuring that it is always fresh. The milk truck driver, a licensed Bulk Tank Milk Grader takes a sample of the milk on each farm. Milk is tested for its content of butterfat, protein, and other solids. It is also undergoes several quality tests, including:

For processors:

1. They know how much milk they will get every day and how much they will pay throughout the year
2. The milk is tested and of high quality
3. Predictability of milk quality and quantity is like a low-risk insurance policy! Processors can focus on their equipment and other needs to make milk products

 At the Dairy Milk is processed into different milk products at the dairy. When it arrives, it is pumped from the milk truck into an even larger storage tank. The milk is tested for flavour, odour, milk fat and bacteria. The milk is pasteurized, homogenized and processed into ice cream, yogurt, cheese, etc

For consumers

1. Fresh milk and other dairy products are available throughout the year
2. Helps to control milk prices (milk in Canada is cheaper than in the United States, which does not have supply management)

QUALITY CONTROL IN THE DAIRY PLANT: Quality control at the dairy plant includes a wide range and scope of activities which have to be carried out regularly. The ultimate task of quality control is to provide the plant management as early as possible with information of the previously defined quality criteria and standards at every stage of the process .Early warning about failures and inability to meet the quality standards at any stage of processing helps to correct the situation in time and to decrease losses caused by a too low quality of the end product. The planning and establishment of quality control for a milk plant includes the following:

– The organization and staffing of the quality control system within the dairy plant. Training of the personnel is essential.

– The definition of quality standards. This has to take into account the legal requirements for raw materials, ingredients, packaging materials, processing line and equipment, end products, storage, handling during distribution, etc.

– The laboratory and the methods of testing and analyzing the quality parameters, including organoleptic, physical, chemical and microbiological methods as well as sampling methods. – The maximum/minimum limits for the quality parameters .Adequate recording and reporting systems.

Quality control laboratory: The task of a quality control laboratory is to organize and carry out all the practical work to control all the activities of a milk processing plant. The laboratory has to be equipped with all apparatus to conduct the required testing and analyzing methods and the necessary staff to facilitate the above-mentioned function.

A quality control laboratory at a milk processing plant the laboratory should be able to control the following:

– Quality of raw milk during collection and at reception;

– Various quality aspects related to processing;

– Quality of the finished milk products;

– Quality of the milk products during storage and distribution;

Cleanliness and hygiene at the milk processing plant .Clear and regular recording of the test results is a must. As well as the regular and timely reporting to the personnel who are responsible for processing and to the plant management.

 

Organoleptic tests: In these tests the milk quality is judged by the use of a person’s senses view, smell, and taste. The organoleptic tests are always used for the first screening of the incoming raw milk. Not any equipment is required. The person carrying out the tests should be experienced for reliable results. On arrival the appearance of the milk and of the lid of the milk can or container is observed and inspected instantly after the lid is removed. The tester smells the milk, observes the appearance, checks the can for cleanliness, looks for sediment, flies, etc. and tastes if necessary. In order to classify the milk according to cleanliness he needs to filter it with a special milk filter. If doubts arise about the quality of the milk after this simple examination, other tests can be carried out in the laboratory to determine the quality.

1. Lactometer or density test: If during the organoleptic inspection the milk appears to be too thin and watery and its colour is “blue thin”, it is suspected that the milk contains added water. The lactometer test serves as a quick method to determine adulteration of milk by adding water. The test is based on the fact that the specific gravity of whole milk, skim milk and water differ from each other. With a lactometer the specific density of milk is measured. At 15 ºC the normal density of the milk ranges from 1.028 to 1.033 g/ml, whereas water has a density of 1.0 g/ml. So when the lactometer reads a value closer to 1.0, probably water has been added to the milk. If possible the lactometer reading can be combined with the fat test. The density of fat is lower than that of milk. So in case the results of the fat test are low and the found density is still high (e.g. 1.035), then the milk might have been skimmed. If the results of the fat test are low and the density is low (e.g. 1.025), then water might have been added to the milk. Always read the temperature of the milk first; the lactometer reading varies according to temperature. Make sure you adjust readings as indicated below. Temperature adjustments for lactometer readings
2. Clot-on-boiling test: This test is performed simply by heating a small amount (5 ml) of milk in a test tube over a flame or by immersing it in boiling water for four minutes. The result can be seen immediately. If the milk is sour or if the milk is abnormal (colostrums or mastitis milk) the milk will clot and not pass this test . Heating will precipitate the proteins in the milk if it is sour. So milk what clots should be rejected. This test is not very sensitive to slightly sour milk, but still very useful. In particular when an alcohol test cannot be carried out . If no coagulation occurs the milk can stand heating operations at the time of testing.
3. Alcohol test: In case there is any reason to suspect that milk is sour, the alcohol test is used for rapid determination of an elevated acidity of milk. The test is carried out by mixing equal quantities (2 ml) of milk and of a 68% ethanol solution (made by mixing 68 ml of 96% alcohol with 28 ml distilled water) in a test tube. If the milk contains more than 0.21% acid, this result in coagulation of the milk proteins and the milk is sour. The milk will clot and is not fit for any process which involves heating, like pasteurization. For above reasons it is recommended that the alcohol test is applied to each and every incoming milk can and container, whenever the milk is to be pasteurized. If the result of the alcohol test indicates a too high acidity, a milk sample can be taken to the laboratory for a more detailed testing by the titratable acidity test.

 COMMON TESTS AT SMALL SCALE DAIRY PLANTS: Two simple and basic tests, which will suffice the requirements of most milk quality control laboratories of small scale processing units, are briefly described here. For the execution of both these tests see a laboratory manual for details.

Titratable acidity test: This test measures the concentration of lactic acid in the milk. If the acidity is higher than 0.18 %, the milk quality is poor and it cannot be heated and processed. For this test you add a sodium hydroxide solution to the milk by titration. The more sodium hydroxide you have to add before the milk is neutralized, the higher the acidity of the milk.

Gerber test to determine fat content: This test is used to determine the fat content of the milk. Some milk is added to a butyrometer together with sulphuric acid and amyl-alcohol. Some expensive equipment, like a special centrifuge and a water bath is needed for this test. The test does not give an a

 Quality control practices: Quality control can be carried out at different levels. It varies from rapid platform tests to more sophisticated and time consuming analyzing methods, including e.g. microbiological quality tests. However, the scope and standard of quality control and the used methodology depend greatly on the size of the enterprise, the volume of production and the product mix. Small dairy plants producing only one product with a limited production capacity have to rely on less sophisticated quality control methods. However, also these should be reliable and cover the most essential quality criteria, like overall hygienic quality of milk and the end products, as well as the hygienic level of operations. The standard of the required quality control and the methodology used should be under continuous evaluation and development, according to increases in and diversification of production and the improvement of processing methods.

III. MILK QUALITY AND HYGIENE PRACTICES AT DISTRIBUTION LEVEL:

Strong cold chain system from dispatch to until delivery of consumer is very essential practice, if the delivery of the goods lapsed in temp, it effects on safety and hygiene, and for product traceability purposes and records are maintained of incoming and outgoing product including damaged goods.  All warehouses have a Product Recall system based upon Product Recall Protocol. Prior to dispatch to customers, finished product is stored in warehouses operated by the dairy company or by external contractors. The effective implementation of a Food Safety Program (FSP) is required for all Ware houses that are licensed.  The FSP must address the prevention or control of potential hazards to food safety, as well as identification and thus traceability of product.

Packaging of Milk and Dairy Products:

Packaging protects the product from bacteriological, light, and oxygen contamination. Liquid milk products may be packed in a beverage carton, which is mainly paperboard covered by a thin layer of food-grade polyethylene on either side. Milk cartons for long-life milk have an additional layer of aluminum foil. Many other packaging materials are also used, ranging from simple plastic pouches to glass bottles, PET laminates and PVC bottles. PET laminates are becoming increasingly popular and are blown at the plant from granulates, generating small amounts of plastic waste when the neck of the container is cut off. Cultured products are packed in beverage cartons or plastic cups and bottles with lids of aluminum foil or paper. In some cases the containers are wrapped together in a carton as multipacks.

In addition to the FSP, the warehouse must have a Product Recall system based upon the Food Industry Recall Protocol. Prior to loading of product, warehouse staff checks the cleanliness of the interior of transport vehicles and shipping containers. Where required, temperature of the product is checked at loading and monitored throughout the distribution chain. Transporters of bulk product between dairy manufacturing plants intended for further processing are required  Containers destined for export are sealed and appropriate documentation is completed prior to shipping. Companies use the AQIS Ex Doc electronic system for certification of dairy exports.

Market: Dairy manufacturers work closely with domestic and international customers to ensure safe and consistent quality dairy products,    the relationship between dairy companies and their domestic and international markets has been developed over years through close communication with customers and consistent delivery of safe quality dairy products.

During marketing of processed products: Public Health authorities are employed by law to check the quality of food stuffs sold for public consumption. Their inspectors may impound substandard or contaminated foodstuffs and prosecute possible culprits.

  The best way to combat the food borne problems is to maintain good hygienic conditions around the storage, packing, processing and marketing places. Precautions should be taken in handling the produce so that there is no damage to the containers and contents remain intact & unexposed to the atmosphere. In case of, agricultural products high sanitary conditions are prerequisite for quality &shelf life. Besides this, sterilization of the packaging material and pasteurization of the product / vacuum packing are other suitable methods to prevent the food from the microbial attack.

FOOD ADULTERATION

Food Adulteration, Food adulteration takes into account not only the intentional addition or substitution or abstraction of substances which adversely affect the nature, substances and quality of foods, but also their incidental contamination during the period of growth, harvesting, storage, processing, transport and distribution. A food adulterant may be defined as any material which is added to food or any substance which adversely affects the nature, substance and quality of the food.

Storage and distribution:

There is a direct relationship between temperature and shelf life. Any increase in storage temperature will decrease the shelf life. During the passage of pasteurised milk through the plant, its temperature will invariably increase slightly. The extent of temperature increase will depend on the length of the pipelines, storage tank design and volume, holding time before filling and filling machine design. Milk which has risen in temperature before filling is difficult to rapidly cool down again after it has been crated and placed in the cold store. This problem can be attended to by placing a plate cooler between the storage tank and the filling machines. The plate cooler, using a water/glycol cooling mixture, will be able to reduce the milk temperature significantly immediately before filling. An additional advantage to installing a plate cooler on the line to the fillers is that the milk may be circulated through the cooler constantly. Using a glycol plate cooler of this type, the filling temperature can be expected to be approximately 2ºC.

The ambient temperature has a significant influence on the temperature rise of liquid milk during distribution, and depends on the type of vehicle used. Air temperatures of 25-30°C can cause an increase in milk temperature of 6-7°C per hour, while outdoor temperatures of 15-20°C can give an increase of 0.5-4°C per hour. This effect is partially reduced by using insulated vehicles. Refrigerated vehicles are the optimal solution to effective distribution, though the drivers require monitoring to ensure that the desired temperature is maintained throughout the distribution route. The temperature of refrigerators and display cabinets in shops must be monitored. The persons responsible for these installations should be required to maintain the temperature below 6°C.

Total Quality Management (TQM) is based on a systematic and holistic approach to production processes and aim to improve product quality while lowering costs. In relation to food safety, Hazard Analysis Critical Control Point (HACCP) has become a widely use tool for managing food safety throughout the world. A stronger emphasis is also being placed on quality due to the need for companies to be more efficient in an increasingly competitive industry. Why need of quality Control and assurance.

QC (Quality Control)                                              QA (Quality Assurance)

• Product Process
• Reactive         Pro-active
• Line function     Staff Function
• Find defects Prevent defects
• How do we achieve quality?

Advantages of Quality Management System

• To Customers
  • Product conforming to the requirements
  • Dependable and reliable product Improved supply
  • Less noncompliance
  • Competitive pricing
  • Favourable response to changes
• To Organization
  • Reduced rejection rate
  • Improved operational results
  • Consistency in output
  • Improved customer satisfaction
  • Increased market share
  • Increased return on investment
• To Employees
  • Defined roles and responsibilities
  • Increased job satisfaction
  • Improved morale
  • Better working conditions
  • Involvement
  • Pride
• To Suppliers and Partners
  • Stability
  • Growth
  • Partnership and mutual understanding
• To Society
  • Fulfillment of legal and regulatory requirements
  • Improved health and safety
  • Reduced environmental impact

 

The golden rule of clean milk production is,“prevention is better than cure”

A contaminated milk contains dust, dirt, foreign material, off flavor, and a high microbial count. Sources of contamination include macro and micro environment around milk like cows body, udder tissue, surrounding soil and air, utensils, fomites, milker, and its belongings, dung, rocking tail etc. Contaminated milk may lead to severe health problems.

Sources of Contamination

1. a) Udder

Unhygienic conditions of milking farms, and bedding material and belongings of animals may lead to microbial growth. As the teat canal remains open for a period of time after milking, these microbes get an opportunity to enter, leading to udder infection such as mastitis which makes the milk unconsumable. Always discard the few strips of foremilk as it contain high bacterial count and dead epithelial cells. Always perform the complete milking as incomplete milking may lead to udder infection.

b) Animal´s Body

Microbes present on the animal´s body may contaminate milk at the time of milking. Maintaining clean skin, flank washing, and cleaning udder with a clean damp cloth before milk decreases the chances of contamination.

c) Milking Farms

Milking farms having good cross ventilation and clean flooring avoid contamination of milk.

d) External Parasites

External parasites like mosquitoes, flies, lice etc may contaminate the milk, so, care must be taken to avoid these parasites by spraying antiparasiticides. Eliminate breeding areas of these parasites like stagnant water, hot and humid atmosphere, etc.

e) Milker

Milker comes in direct contact of milk and hence responsible for primarily contaminating the milk. Dirty hands, belongings and clothing of the milker may act as the source of contamination. Several microbial diseases may transmit from the milker to the milk. Persons having sign and symptoms of diseases like dysentery, tuberculosis, diphtheria, and typhoid must be avoided to perform milking. Bad habits like drinking, and smoking must be avoided.

f) Utensils

The containers or equipment in which the milk is handled, processed, stored or transported are called utensils. Clean, dirt and dust-free, sanitized or disinfected, smooth copper free and dry utensils should be preferred in milking.

g) Methods of Milking

Milking with wet hands or using a bend thumb against teats (called knuckling) leads to contamination of milk. In rural areas, milkers moisten their fingers with milk, water or saliva, to perform milking. This must be avoided. Wet hand milking leads to harsh and dry chokes, cracks and sores on teats predisposing it to infection and finally leading to milk contamination. Knuckling causes damage to the teat tissue which leads to udder infection. So always practice dry hand milking with full hand milking method (grasping teat in palm by encircling between thumb and four palm fingers).

Steps in Clean Milk Production

• Always wash the animal before milking,as it minimizes microbial entry.
• Promote dry udder practices because moist udder lead to milk contamination by dirty drops falling into the milk. Hence, udder should be washed, clean and sanitized, and finally should be wiped out using dry cloth.
• Proper washing, cleaning and sanitization of milker´s hand must be done followed by wiping with clean dry cloth to avoid wet hand milking.
• Proper and complete hygiene of milker is necessary like short hairs, trimmed nails and proper bath.
• Milker should be free from all diseases and must not have any disease which is a potential source of milk contamination like dyssentry, tuberculosis, diphtheria, typhoid.
• Never feed dusty feeds to animals during milking and reduce animal movements during milking by providing the concentrated feed.
• Proper restraining of animal is necessary during milking as it may lead to milk. contamination, for example by using milker´s knot on hind legs above hock joint and tying of tail.
• Milking farms should be properly washed, cleaned and well ventilated and also free from flies and other parasites.
• Use clean, sanitized, smooth and copper free utensils for milking.
• To avoid undesirable smell and taste in milk, feed flavour producing feeds after milking.
• Discard first few drops of milk and use small mouthed container covered with muslin cloth to collect milk.
• After milking cover the container properly to avoid environmental contamination.

To increase shelf life and keeping quality of milk, properly store milk in cool and dry place and may refrigerate or freeze if long time storage is provided.

Milk Hygiene

In case udder is healthy and normal, the milk is sterile. Most of the contamination occurs during and after milking. Use mastitis control routines at each milking to reduce the proportion of infected cows and clinical mastitis cases. With better management and care, milk contamination can be avoided. Perform dry udder and clean milking practices. As milk is a good media for microbes, proper storage and handling is very necessary.

Udder Health

Udder should be maintained clean as it avoids source contamination before milking. The greatest economic loss to dairy industry is by mastitis. Management of cows should be like that their udders and teats are clean and milking is to be done  in such a way that minimizes microbial contamination. Keep udder covered with a cloth so that dust and dirt especially when animal lies down is restricted and always perform teat dipping after milking and not allow the animal free to lie down for few minutes after milking because pores of teat canal remains open after milking for sometime which leads to direct microbial entry into the udder.

Points to be Noted

1. Never drink or promote consumption of unpasteurized or unboiled milk as it may lead to life threatening situations. 
2. Perform milk and udder examination time to time by consulting a veterinary doctor.

Conclusion

As milk is an important diet source in Indian food habits and it is also a perishable product, and if consumed or stored or handled unhygenically it may lead to development of diseases which may be life threatening or zoonotic (diseases which transmit from animals to humans like brucellosis) in natrure. So, focus should be given on clean milk production, milk hygiene and udder health so that economic loss and loss of healthy life can be avoided.

HYGIENIC PRODUCTION OF MILK

CLEAN MILK PRODUCTION

HYGIENIC PRODUCTION OF MILK

Compiled  & Shared by- This paper is a compilation of groupwork provided by the Team, LITD (Livestock Institute of Training & Development)

 Image-Courtesy-Google

 Reference-On Request