Milk-and-Dairy-Products-in-Human-Nutrition-FAO

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Milk and dairy products in human nutrition
Maximum permissible limits for antibiotic residues in foods are established
to ensure prudent use of antimicrobials and safeguard public health. Excessive
residues of antimicrobials in milk can also affect processing because they may
partially or completely inhibit acid production by starter cultures in cheese- and
yoghurt-making, or inadequate ripening and ageing of cheese and resultant flavour/texture
defects.
Residues in milk can be minimized by adhering to good veterinary and husbandry
practices. FAO and WHO (2009) sets out the overarching principles and guidance
for governments on the design and implementation of national and trade-related
food-safety-assurance programmes for residues of veterinary drugs and provides
guidelines on best use of veterinary drugs by food producers and processors.
In practice, at the national level each registered antimicrobial preparation has a
recommended withdrawal time before milking which must be adhered to in order to
avoid excessive levels of residues in the milk (Fischer et al., 2003). Failure to adhere
to withholding periods is the most commonly cited reason for drug residues in
marketed milk in temperate countries (Zwald et al., 2004). Other important reasons
why residues occur at excessive levels include incorrect route of administration
and dosage, use of antimicrobials not registered for dairy cows and incorrect use
without taking into consideration lactation status.
Antimicrobial resistance
Antimicrobial drugs play a critical role in disease prevention, thus contributing to
animal and human health. However, the misuse or inappropriate use of antimicrobials
for treatment and prevention of diseases in food animals may lead to the emergence
and spread of micro-organisms resistant to antimicrobials, leading to reduced
effectiveness of antimicrobials in treating diseases in humans and animals. The
risk appears to be greater in countries that have weak, inadequate or non-existent
national policies, regulatory, surveillance and monitoring systems for antimicrobial
resistance and antimicrobial drug usage. To address this issue at the global level, the
Codex Alimentarius Commission has adopted guidelines for risk analysis of foodborne
antimicrobial resistance (FAO and WHO, 2011a) and a code of practice to
minimize and contain antimicrobial resistance (FAO and WHO, 2005).
Antimicrobial resistance is not a great concern where milk is routinely pasteurized
or receives equivalent processing, because these inactivate bacteria. However,
it may be of concern where:
• pasteurization is not mandatory or is mandatory for cow milk but not for
milk from other species, e.g. sheep, goat or camel;
• post-pasteurization or processing contamination occurs (this is not common
but does happen);
• dairy products are made from unpasteurized milk or cream, particularly soft
cheeses where processing does not inactive bacteria sufficiently; or
• consumers prefer unpasteurized products.
Growth promoters
The growth promoter of most relevance to milk and dairy products is recombinant
bovine somatotropin (rBST), a hormone used in some countries to increase milk
production in lactating bovine cows (Khaniki, 2007). FAO and WHO (1998)