Australian chickens are not given hormones in any way. Their size occurs naturally due to selective breeding and optimal nutrition.

A key reason may be that the chickens sold these days in supermarkets, butcher shops and chicken shops are much bigger than what they may recall them to have been 20, 30 or 40 years ago, and it may be easy to conclude that this must be the result of some unnatural intervention. The actual reason for this increased growth rate and size is the ongoing selective breeding programs and improved animal husbandry over the past 60 years.

• Feed is made up of 85-90% grains, such as wheat, sorghum, barley, oats, lupins, soybean meal, canola and other oilseed meals and grain legumes.
• Hormones are not added to chicken feed or administered to commercial meat chickens or breeders in Australia. Hormone supplementation is a practice that has been banned internationally for over fifty years.
• Meat chicken diets are formulated to strict nutritional standards.

Traditional breeding techniques, also called selective breeding, involves selecting the chickens with the most desirable traits (genetic characteristics) as parents for the next generation and repeating this generation after generation (there are about 50 chicken generations to every human generation so that the past 50 years of commercial breeding are equivalent to over 2000 years of human evolution).

This simple but effective mechanism has allowed all agricultural industries (grains, horticulture, dairy, meat etc.) to improve their products and their productivity.

Poultry is no different from the other sectors in this respect, although the process is more effective because of the greater control over it, the international approach, the large number of breeding animals that can be maintained and the shorter generation times.

Soya bean meal, which provides an important source of protein and amino acids in the chicken diet, is not usually available in sufficient quantities in Australia and has to be imported.

Much of the world’s soya bean production is genetically modified and in countries such as the US, traditional soya bean meal becomes mixed with genetically modified meal during processing, storage and distribution. Guaranteed non-GM soya bean meal can no longer be sourced in sufficient quantities to meet the poultry industry’s needs and thus chicken feed will often contain GM soya bean meal. Another important source of protein and amino acids in chicken diets comes from locally grown canola seed. About a quarter of all canola grown in Australia is GM.

Chickens are not genetically engineered or modified. Improvements in their growth, feed conversion efficiency, tenderness and other characteristics are entirely due to traditional cross-breeding and selective breeding techniques.

Meat chickens have been selectively bred over the past 60 years for a variety of characteristics, including growth rate and efficiency to convert feed into meat. This is why they reach the desired market weight and quality more quickly than the progenitor breeds of chickens from which they were originally derived.

Two answers to this one:

1. If you are referring to the different sizes sold in supermarkets or other retail outlets, then the answer is that the small ones are younger and not yet fully grown.
2.  Chickens bred for meat will also be much larger than chickens bred to lay table eggs for human consumption –  both are chickens but they are very different breeds. It’s like a poodle and a German shepherd – both dogs, but very different. 

Australia is internationally accepted to be free of avian influenza in poultry flocks, and the risk of an outbreak is low due to the strict biosecurity protocols that are in place. In the rare event of an outbreak of avian influenza occurring in an Australian poultry flock, the industry, in partnership with the government, has a well-rehearsed and up-to-date response plan which would come into play to rapidly eradicate the disease.

Australia is extremely well prepared for such a possibility – the key to control is early detection and notification and rapid tracing of birds and products to remove any possible source of infection from the supply chain.

Antibiotics are sometimes used to treat or prevent disease in chickens but regular independent testing conducted by the National Residue Survey shows that there are no unsafe antibiotic residues found in chicken meat.  The use of antibiotics is strictly regulated and administration is under veterinary supervision.

The regulations ensure that antibiotics that can find their way into the meat is not used or only used at an early stage of the
bird’s life so that there is sufficient time for any residue to be naturally degraded. Given that no unsafe residues are found in Australian chicken meat, even people with allergies to certain antibiotics don’t have to miss out on eating delicious Australian chicken.