Livestock animals are facing a higher load of pathogenic stressors compared to wild animals. Intensive
growth, high metabolic rates, dense population and environmental burdens are leading to an increased
susceptibility to diseases. Of course, every individual is endowed with attributes for self preservation. It´s
almost axiomatic, that every multi-cellular animal possesses mechanisms to oppose invasion of its body
by potentially harmful foreign agents (Myrvik, 1999). The body is protected from infectious disease by
an extraordinarily complex, intricately regulated, and highly efficient network of cellular and biochemical
activities. Survival depends on the body’s ability to perceive and respond to potential pathogens (Grossman,
1992).

“Too few new drugs are being developed to replace those that have lost their effectiveness. In the race
for supremacy, microbes are sprinting ahead” (WHO, 1996). Microorganisms are permanently adapting to
their environment. It is known from practice, that feeding strategies and veterinarian concepts are working
for a certain period and reduced in their efficacy after some time. This effect is seen on a regional, even farmindividual
basis. In the field of evolutionary hypothesis, this effect is called the “Red Queen Effect”.

The Red Queen Effect

The term “Red Queen Effect” was taken by Leigh von Valen from the Red Queen’s race in Lewis Carroll’s „Alice in Wonderland“ in 1973. The Red Queen said, “It takes all the running you can do, to keep in the same place.” The Red Queen Principle can be stated thus: “For an evolutionary system, continuing development is needed just in order to maintain its fitness relative to the systems it is co-evolving with.”

Adapted to livestock production, this means, that continuously new challenges can be expected due to a permanently amending and adapting pathogenic micro-flora and due to the changing regulatory frameworks. The ban of antibiotic growth promoters in the EU in 2006 led to a rising incidence of digestive disorders and finally to increasing requirements
for antibiotic treatment. If you don’t go forwards you go backwards.

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Lines of defence

Livestock animals require a dense network of defence mechanisms to keep them on high performance levels. This includes the innate and acquired immune system as well as a biosecurity-, veterinarian-, feed and feed-additive system.

Biosecurity and hygiene

Biosecurity is defined as “the prevention of pathogenic microorganisms from contacting animal populations”. Biosecurity is based on the simple idea that disease cannot occur if the pathogen that causes the disease is not present at the right time (Morrow, 2006). A Biosecurity program covers the wide range from disinfection to transport regulations.