What your FCR is really telling you

FCR (Feed Conversion Ratio) is total feed fed divided by the weight of shrimp gained. An FCR of 1.5 means you fed 1.5 kg of feed for every 1 kg of shrimp grown. Lower is better.

As a rule of thumb for vannamei: 1.0–1.2 is excellent, 1.2–1.5 is good, and above 1.7 means something is wrong — usually overfeeding, low survival, or a health/water problem eating into growth.

The trap is that FCR looks fine early and drifts up late in the cycle. Watch the trend, not just the number: if feed keeps rising but sampling shows little extra weight, your feeding efficiency has dropped. Check trays, cut the ration, and check water and health before you keep pouring feed into a pond that is not converting it.