Bigger roosters make bigger broilers

If you live on a farm, then you have probably helped to select the sire for the next generation of at least once species in your operation. Whether you bred cattle, horses, sheep or even dogs, the biggest sires tend to produce offspring that mature at larger sizes. The same holds true for poultry as well. Rate of growth is heritable in broilers and turkeys and selecting for sires that are the largest at a particular age has been a basic part of the selection process of poultry for decades.

Primary breeders produce strains of birds with improved characteristics by exerting a high degree of selection pressure for the desired traits, which means that only birds that grow the fastest or have the most breast meat are used to create the next generation. Ultimately, these highly selected lines of birds are multiplied for a couple of generations to increase their numbers and then the lines are crossed to provide hybrid vigor in the generation of chicks or poults that are raised as meat birds.

Selection pressure is applied on each generation of birds in the multiplier phases. Poultry integrators are buying a gene pool from the primary breeder when they purchase parent stock, and the integrator must manage this gene pool to maximize the performance of the offspring.

The basic idea in the parent flock barns is still to get the biggest roosters or toms to sire as much of the next generation as possible, but sometimes that isn’t what is happening.

It is a common industry practice to restrict feed on broiler breeder males to keep them from getting too heavy. Dr. John Brake, professor, poultry science, North Carolina State University, said that his research has shown that this feed restriction means that the largest males are being underfed.

“Current breeder standards call for weights that are too low,” Brake said. Roosters need to be allowed to be bigger so that they will stay fertile and produce the biggest broilers. “When fertility in the flock goes down, the biggest males are not mating,” Brake said. “If you control body weight of the males in the breeder house, the big birds are under fed. You have to feed the big birds and maybe the big pullets to get big broilers.”

Turkeys are bred commercially via artificial insemination and this gives the industry the opportunity to select the males that it uses as sires. The optimal strategy would be to use the largest toms as much as possible and use smaller toms as sires only on an as needed basis. Dr. Kenneth Krueger, consulting geneticist, said that most turkey companies are not maximizing the use of the largest toms. Turkey breeders tend to milk all of the toms and pool semen samples and use a standard volume of semen with extender for each insemination. Technology developed to measure sperm viability in humans is now available for use in turkeys. The Sperm Quality Analyzer allows for semen samples to be quickly evaluated for the concentration of viable sperm and it calculates the dilution rate to give a standard number of sperm cells per insemination. Employing this technology can allow turkey companies to maximize the use of the largest toms as sires and can push up the weights and lower the feed conversions of the next generation of meat birds.

The goal of a parent flock breeding program should be to produce the desired number of offspring with the best genetic material possible. To get the best growth rate from the offspring, the answer to the question of “Who is the daddy?” needs to be only the biggest boys in the house.