healthy chooks on the way, page-4

re: new product to launch The sheer size of the global poultry broiler industry is staggering, almost 40 billion chickens are
hatched worldwide every year. The Australian industry produces approximately 350 million broilers
per annum. Chicken meat represents approximately 40% of all meat consumed and is a $150 billion
per annum global retail market, as well as supporting a multi-billion dollar poultry health market.
Chickens are reared under intensive conditions which are conducive to infection by opportunistic
pathogens. This is especially critical during the first weeks of life, a time at which the immune system
has not yet fully matured (Lowenthal et al., 1993) and when levels of maternal antibody are declining.
A major problem faced by intensive livestock industries, such as the poultry industry, is loss of
productivity due to disease, therefore considerable resources are required in order to maintain the
health status of these animals.
The main mechanisms by which disease is controlled involves the use of vaccines and antimicrobials.
Vaccines are used to provide long term specific protection against a particular pathogen following a
small number of immunisations. In contrast, protection provided by antimicrobials (as in-feed
antibiotics and chemicals) is broad spectrum and requires their continual usage even in the absence of
apparent disease. Antibiotics have been used to treat and control diseases in livestock and poultry for
more than 50 years. Low levels of antibiotics are used as feed supplements (in-feed) for their ability
to enhance animal health and result in improved growth rates and feed-conversion efficiency
(Williams, 2001). Because of this, in-feed antibiotics are often referred to as growth promoters.
Unfortunately, the extensive use of antibiotics and chemicals over a long period of time has resulted
in the emergence of pathogens that have become resistant to such treatments. The World Health
Organisation has now recommended restrictions in the type of antimicrobials used in food production
animals and has recommended the development and use of alternative, environmentally-friendly
methods to control disease.
Some countries have already implemented such restrictions and based on their experiences, it is
anticipated that without appropriate substitutes for prophylactic antibiotics, particular microorganisms
may emerge as significant health problems (Bedford, 2000). One example is the predicted
increased prevalence of Clostridium species, leading to severe cases of necrotic enteritis and other
gastrointestinal problems, resulting in decreased productivity and welfare in poultry. Replacements
for current growth promoters in livestock are therefore a very high priority for the industry.
Faced with these restrictions and potential problems, the Australian poultry industry is supporting the
development of alternative measures that will maintain productivity as well as ensuring the highest
possible levels of animal health and welfare.
Another major problem faced by the poultry industry is related to vaccines which are designed to give
high levels of protection to specific diseases. Vaccination strategies are the primary mechanism for
the control of most parasitic, viral and bacterial pathogens. There are, however, mounting concerns
over the effectiveness of current vaccines in the face of emerging of hyper-virulent strains. There is a
need for alternative vaccines, however, killed and recombinant subunit vaccines do not usually offer
an adequate level of long term protection and often require the use of adjuvants to enhance their
activity. Oil-based adjuvants, however, induce adverse site reactions resulting in decreased meat
quality and animal discomfort. At this time there is a lack of suitable, cost effective adjuvants for use
in both the broiler and egg layers.