EDMONTON — The modern broiler chicken is the result of intensive breeding programs , in which only 3,000 of one million males are selected.
Unlocking the mysteries of chicken DNA has been a successful approach to feeding a hungry world by producing a fast growing, heavier, meatier bird.
“If we hadn’t delivered with genetics improvements, it would be a really different story,” said Mitch Abrahamson of the international broiler breeding company Cobb Vantress.
“The results we got from this program were better than we thought they were going to be.”
Sixty billion chickens will be slaughtered worldwide this year, up from six billion in 1961. Modern birds are two pounds heavier, which means another 25 billion birds would have been required to meet world demand if that added weight had not been achieved.
The company first considered using genomic information in 2005, he said at the annual Livestock Gentec conference held in Edmonton Oct. 13-14.
It takes seven to eight years to develop new genetics, and the company has spent an additional $145 million on genetic research in the past five years.
“Genomics delivers some advantages to a breeding program,” he said. “Whether you can afford it or not is a different question.”
Genomic information revealed which birds were better than others, even when they looked identical.
“It turns out 40 percent of what were the best birds, we were throwing them away,” he said.
Each chick is identified with a unique wing band with a data chip that includes a 15 generation pedigree and 40 other points of information about the bird.
DNA has been used to check pedigrees, which found errors in parentage. Researchers were able to find the most productive roosters once these errors were corrected.
Phenotypic information is needed to develop genomic traits.
The research and breeding program starts with two million chicks and ends up selecting 36,000 females and keeping 3,000 males as breeders.
“We are really looking for that gold medal athlete, that really unique individual that can move genetically lots of these traits all at once. They are hard to find,” he said.
Researchers collect data on production traits and profitability. They want breeder birds that offer better feed conversion, high meat yield, growth rate, egg production and strong, healthy legs, hearts and lungs.
They have data for more than 40 physical traits, and every bird is examined for gait scoring, joint health and blood oxygen levels.
Feed conversion is measured daily, which is how much the birds eat and how much they gain. Breast meat is measured with ultrasound and dissections.
An average broiler carcass is 28 percent breast meat, compared to 17 percent in 1990.
“You can change the product pretty quickly if you have the technology and the goal and desire to do that,” Abrahamson said.
The company may have succeeded in building birds with more breast meat, but the tradeoff has been complaints about tough, dry meat.
Improving meat quality is on the priority list for further research.
Other research is evaluating feed efficiency because that is 70 percent of the cost to raise a bird. Alternate feeds and greater efficiency are desirable.
Feed costs have increased to $34.88 per bird from $12.33 in 1990, which accounts for 70 percent of the cost of bird production.
However, improvements have been made: it now take 1.5 pounds of feed to make a pound a meat compared to 2.2 lb. of feed in 1990.
Other research is studying disease and ways to restrict antibiotic use, but pedigree farms are incredibly bios cure, which means it is hard to select for disease resistance when the birds are never exposed to anything.
Genomics will continue to be a valuable tool in developing better chickens, said Abrahamson. Results were better than they thought they might be, and their achievements could probably be extended to other livestock sectors.