The chicken family tree in Australia

Posted by Contributing Author - Vivien Kite on 29th August 2016
Broiler Farm 2194 - market age meat chicken

In 2016, Australian chicken farms will produce over 590 million meat chickens. But where do they come from?

It may be obvious, but it’s something most people don’t think about – every meat chicken has a set of parents, and those parents have their own parents, and so on up the line. But where are these parents, grandparents and great grandparents? Where are they kept and what do they look like? And how does the whole chicken breeding and multiplication process work?

This is the story of the Australian meat chicken’s family tree…and it starts, not here in Australia, but overseas in the nucleus breeding operations of the world’s two largest poultry genetics companies.

Our chicken genetics come from overseas

Almost all of Australia’s meat chickens are derived from two large international poultry genetics companies – Aviagen and Cobb – and the specific hybrid breeds used here (referred to as ‘Ross’ and ‘Cobb’) are pretty much the same as are used right around the world. Because of the size of their breeding operations, and therefore the numbers of birds and flocks they can maintain and are therefore available to select from, these genetics companies have powerful selective breeding programs and are able to make significant improvements to the genetic potential of their breeds at each generation. We call the genetic flocks they maintain the ‘nucleus’ breeding flocks – and it’s all achieved using conventional selective breeding techniques.

In a previous blog (see selective breeding), I described how selective breeding works, why it’s done, and what attributes the breeding companies select for.

How do we get these genetics into Australia?

New genetic lines of meat chickens developed by the international breeding companies are imported, under strict quarantine, as fertile eggs. Typically, there might be, say, 12,000 fertile eggs in a single importation, and 2 – 3 new importations each year for each major breed. These fertile eggs are hatched out in quarantine stations in Australia before being released to breeder farms. We refer to this generation as the Great Grandparents (GGPs) of the meat chickens that are for eating. In actuality, at any importation there are a variety of different lines introduced. It’s a little complicated to explain, but this is done to provide for optimal attributes in the male and female lines of later generations, and to capture hybrid vigour in later generations. A little more on that later.

 And what breeding happens in Australia?

The GGPs that come out of quarantine stations are housed in highly biosecure farms around Australia and themselves go on to produce fertile eggs that are hatched to produce the next generation – the Grandparent (GP) generation. The Grandparents are then used to produce a Parent (P) generation, and finally these Parents are mated to produce fertile eggs that hatch to become the ultimate generation – the 590 million meat chickens that are used for meat consumption annually.

At each breeding step, two things happen. Firstly, there are different breeding lines crossed to produce crossbred male and female lines for the next breeding generation and, secondly, the number of birds in the subsequent generation is multiplied up. Once mature (at about 20 weeks of age) each breeder hen can produce about 130 offspring in a single year.

The whole process is represented in the infographic below. This shows how the numbers of individual birds in each generation steadily increases through to the ultimate meat chicken generation, and – voila! – we end up with 590 million meat chickens.

Why do we import new Great Grandparents? Why don’t we just use existing meat chickens to breed more of the same?

The answer to the first question is simple….we import new chicken genetics on an ongoing basis because the strains are improving all the time. We would fall behind the rest of the world, and fail to deliver the benefits that ongoing selection offers to consumers, if we didn’t do so.

And while the meat chicken generation is perfectly capable of going on to maturity and themselves produce offspring, they are generally not used for breeding. The reason why they aren’t used is that, as I mentioned previously, several different genetic lines are brought in at each new importation, each of which has specific characteristics desired in the next generation. These lines are then crossed to produce a subsequent generation which differs again from the one before…and so on. The use of crossbreeding is common in animal production – it creates a stronger, more robust progeny due to the principle of ‘hybrid vigour’, whereby the robustness and health of the cross is greater than the average of their parents. It’s the opposite of inbreeding – a concept people may be more familiar with. The greater the genetic differences between the parents, the more to gain from hybrid vigour. In the case of the Parents of the ultimate meat chicken generation, the male and female parent lines each also bring their own characteristics – the male, good muscling and body weight, and the breeder hen the capacity to lay plenty of fertile eggs to be hatched into meat chickens.

So the meat comes from Australian chickens?

Yes – the chicken meat available across Australia is almost exclusively from meat chickens grown in Australia, even though their ancestors may have come from other parts of the world. They are genuine “fourth generation” Australian meat chickens.

But… what comes first?

Well, the above may not answer the age old rhetorical question “what comes first…the chicken or the egg?” but I hope it helps to explain a little about the breeding processes required to deliver the 590 million meat chickens required to meet the demands of Australia’s chicken meat consumers each year.

 

This article was written by the Australian Chicken Meat Federation