Milk, daily used dairy commodity, its contamination and recommendations for safe milk production

Milk can be regarded as a nutritionally complete food, containing protein, fat, lactose, vitamins and minerals, together with natural enzymes and those derived from microorganisms within the milk (Dhamala, 2018). Milk and their by-product act as a favorable medium for the growth of the various micro-organisms and thus are susceptible to various microbial contamination (De Buyser, Dufour, Maire, & Lafarge, 2001). 

Contamination of milk may occur through various sources. May be through infected cow with tuberculosis, brucellosis, and mastitis and also from milk handlers infected with typhoid fever, diphtheria, dysentery, and scarlet fever (Jay et al., 2005). Poor pre-milking hygienic practices may lead to the milk contamination which ultimately have risk to consumer. Thus, the safety of milk and their by-products is of prime importance to ensure the public safety. This is a serious challenge particularly in developing and under developed country where the milk and their products are prepared adopting the unhygienic practices (Dhungel Maskey; Bhattarai; & Shrestha; 2019). The rules and regulations to ensure the public safety in developing country like Nepal is not strictly followed, thus, milk borne diseases and health risk is higher.

Milk is considered to be a complete food as it contains almost all the nutrients required by both children and adult human. It is a valuable source of carbohydrate, protein, fat, vitamin and minerals. Despite the nourishing and wholesome effect of milk, milk produced and handled under unhygienic condition can be a source of several diseases. In some cases, milk may render serious human health hazards. Therefore, it is very essential to control production, processing marketing of milk at all stages (Yadav et al., 1993). Lack of clean milk production and good manufacturing practices (GMP) during production stage  has been a major issue. In addition to  this, chances of transmission of zoonotic diseases and milk adulteration practices are the other important issues to be taken under consideration. The major causes of adulteration are increased consumer demand, aqueous and opaque properties of the milk, unscrupulous producers/traders, perishable nature of milk, and lack of effective legal standards and enforcement, and lack of reliable and rapid milk adulteration detection kit (Kamthania et al., 2014)

Points to be considered to avoid the milk contamination:

Environmental Hygiene:

Water contamination, and for example pests (such as insects and rodents), chemicals and the both internal and external environments where the animals are housed and milked, may contaminate feed, milking equipment or milking animals leading to the introduction of potential hazards into the milk.Thus, the environmental hygiene is crucial for avoiding contamination.

Premises for milk production:

Improper and poorly maintained premises have shown to contaminate the milk.

Animal Health:

Milk and milk products obtained from the diseased animals are unsuitable for consumption by consumers. Thus, it requires the proper maintenance of the healthy animals that help to reduce the likelihood that pathogens to be introduced into the milk via the mammary gland or from the faeces. It is important to prevent the spread of zoonotic diseases among animals and from animals (including milking animals) to milk.

Suggestions/Recommendations: Provide Farmer level training and awareness programs related to high-quality milk production. Also, Milk collection centers and chilling centers should improve their existing facilities and organize the milk collection schedule so that the milk collected at farm reaches the chilling center within 3 hours of milking, which checks bacterial growth.