How did selective breeding improve growth and feed efficiency in commercial chickens?

Selective breeding has significantly transformed commercial poultry production by applying fundamental genetic principles to achieve faster, more efficient growth and higher yields.1

To improve these traits, breeders utilize a combination of techniques:

• Genetic Systems: Breeders employ intensive mass selection alongside inbreeding and crossbreeding to isolate and propagate desirable traits.1
• Hybrid Vigour: By utilizing heterosis—or hybrid vigour—through incrosses and crossbreeding, producers have successfully developed strains that exhibit rapid weight gains and produce high-quality, meaty carcasses.1
• Specialization: Historically, meat was a byproduct of egg production. However, through targeted breeding, the industry developed specialized strains for either maximum egg production or efficient meat growth.1

These advancements have been dramatic. In the mid-20th century, a broiler chicken required four months to reach market weight; today, a modern broiler can reach a 2.3-kg (5-pound) market weight in just five weeks. When paired with highly perfected nutritional science, these genetic improvements allow modern broilers to produce approximately 0.5 kg of meat from only 0.9 kg of feed.12