What is feed conversion ratio and what is a good FCR for broilers?

Feed conversion ratio, or FCR, measures how efficiently broilers turn feed into live weight: total feed consumed divided by total live weight produced over a cycle. Lower is better, provided birds still meet health, growth and market requirements. It measures live-weight efficiency, not feed per kilogram of dressed meat.

A good commercial benchmark is around 1.55–1.65 near 42 days, depending on final weight and how feed and output are counted. Ross 308 broiler performance objectives place the common commercial target near 1.55 at about 2.8 kg and 42 days, while the weekly objectives give about 1.65 near 2.96 kg at the same age. These are good-condition performance objectives, not guarantees; heat, stocking pressure and poor litter can worsen results.

For example, the supplied Cobb 500 plan targets 2.75 kg at 42 days with an FCR of 1.57 in an environmentally controlled tunnel house at 17C ambient temperature. That means 1.57 kg of feed for each kilogram of live weight produced on the stated reporting basis. Here, realistic and standard FCR are both 1.57, so this is a strong planned result rather than proof of what a flock will achieve.

Standard broiler performance reporting practice says to include wasted and spilled feed, and include the weight of birds that died only if their feed consumption is also included. Always state slaughter age, live weight and mortality treatment alongside FCR. Compare like with like: heavier birds generally have worse cumulative conversion, and FAO smallholder poultry guidance puts dual-purpose birds around 2.4 near 1.8 kg at about 12 weeks, so commercial broiler targets are not appropriate for every flock.