Creating the modern broiler
Recently retired Dr. John Hardiman looks back on his time in broiler research and offers some ideas for the future.
Dr. John Hardiman retired from Cobb-Vantress Inc. at the end of 2013. For almost 30 years, he was at the helm of the research and development program that introduced the Cobb500 to the U.S. in the 1980s. He talks about some of the issues he had to confront and looks ahead.
Roger Ranson: What over those three decades do you see as the major milestones in the way the bird has improved?
John Hardiman: Well, when we first brought the bird in, we knew about growth rate and we knew that meat yield was important. That was why we wanted access to the Cobb500 lines from the UK.
It was only after we put the new Cobb-Vantress company together that we started to devote more time and money to pure feed conversion selection. If we hadn't taken that step then, we would have been too late. But we did start very strongly and a lot of the credit goes to Terry Wing for bringing in new technology for analyzing and measuring feed conversion.
We continued to select for meat yield, particularly breast meat yield. What was once called "bloom" in the UK became breast meat yield for deboned products in that growing segment of the U.S. It was so critical that we played on that trait and, at the same time, four of five other characteristics using more selection technology.
We asked ourselves, "Can we do all this and manage to hold the hatchability and at the same time be able to get more eggs per hen housed per year?" That was a very successful story. We've averaged over the past 20 years about an egg a year. And that was complemented by building a world-recognized technical service group so that we could offer the customer much more extensive help. That team helped people understand the bird, breaking any perception that you couldn't improve reproduction.
A couple of traits stand out. We started to select for blood oxygen so that we could have a concrete measure of heart and lung efficiency in addition to feed efficiency, and also we experimented with ultrasound to image live birds for meat yield. We started that in the 1980s, and as we went into the '90s, the equipment was better and technology was better.
Ultrasound measurement helped a lot in determining meat yield, and as we go forward, technologies like that become mainstream in the breeding program. Then there is what Tony Barnes, former Cobb president, used to call meticulous repetition - do the same thing well over and over again, but do it not on thousands; do it on millions of birds.
RR: If we set aside genomics, which of all the selection techniques has made the biggest impact in the program over these 30 years?
JH: One word I'd use to describe the Cobb breeding program is balanced, and I think it is the sum of all these different technologies [and] the fact that we didn't look at the breeding program from one way. We allowed an increasing number of people to come together in a multiple trait program.
We knew it was going to take an awful lot of chickens to find the bird that has everything we wanted. So we increased the numbers and worked on a fast track pedigree program where we were putting a new flock down several times per year - not just once or twice.
The traits perhaps most necessary to the industry have been improved - feed efficiency and increased meat yield - not just breast meat yield but carcass or eviscerated yield. At the same time, we improved livability.
Certainly, if one looks in the '80s and '90s, even at the beginning of the millennium, we saw that the Cobb500 had the disease resistance and robustness to survive with appropriate management in most environments of the world. This was the result of continuous strong selection for pedigree bird livability and also new research in disease resistance started by Igal Pevzner.
RR: We increasingly see genomics playing a bigger role in the industry. How has it influenced the breeding stock you sell to customers today?
JH: Yes, we've benefited to date. We've been able to target specific disorders and select more efficiently against them. Genomics won't replace the phenotypic selection methods we use today; it will augment them. It's an evolution. I don't think it's a revolution.
But looking back in 10 or 20 years' time, we will call it a revolution. Not a landslide victory on everything [with] certain traits benefiting more than others, and there are so many more of these markers we have to discover. It's a great job for a molecular geneticist.
RR: You're genotyping hundreds of thousands of chickens, something that perhaps only the two or three breeding companies can do, but how concerned are you about the diminishing gene pool and genetic diversity, which is a factor today in the industry?
JH: You know, there is almost an irony in this, because the more we learn about the chicken genome, the more diverse we find birds to be. If somebody took the premise that the diversity of today's broiler chicken is less than that of the ancestral Jungle Fowl, that could be true.
But if you were to take, let us say four commercial lines of today's chickens and cross them, like we do in the Cobb500, you'd find by bringing together the genomes of four different, isolated groups of chickens and crossing them into a broiler, you'd restore the vast majority of the genetic diversity of the last few hundred years.
Each of these lines is quite different from each other, and while one line by itself doesn't represent all the diversity one might want for the future, when we retain a large stable of lines and cross them, it restores a tremendous amount of diversity. So I would say as long as we are smart enough to always have other lines on the sidelines, I don't see a diversity issue for many, many decades to come.
In fact, it's more likely other factors in our society or culture will affect decisions long before diversity would restrict further genetic improvement.
RR: How do you think the Cobb broiler is going to look in 20 or 30 years' time?
JH: You know, there's a certain beauty in growth rate. It's an amazing story that people today are so confused about. It's only through improving how fast an animal grows that we can keep the price of chicken at a sensible level. It is the only way that we can improve efficiency. If we select for growth rate, we also get about half the feed efficiency improvements we make today. Without that, we would have much more of an issue with housing and with effects on the environment, more of an issue with carbon footprint, and about corn for the future.
So if we look forward into the next 10 to 15 years, we'll see many traits be they animal well-being or environmental traits going forward. And we'll also see this miracle of improved growth rate helping to feed people and increase the efficiency of production. I think we're going to see this miracle continue for another 15 years.
But in 20 years, logically speaking, the bird is going to reach marketable weight in some cases as early as three weeks and maybe even larger birds at four weeks or a little more. Before that time, for a variety of reasons, it would probably be wise for alternative products to be sold to give people options. Maybe we'll have gone as far as we can and need to in growth rate, and we'll look for other selection criteria.