Layer Feed Formulation Calculator

Metabolizable Energy (ME) splits into two additive terms: ME for Maintenance uses a body-weight scaling law (bird weight converted to kilograms, raised to the 0.75 power), an approximation widely used in poultry nutrition reference literature for basal maintenance energy needs, and ME for Production is a flat 2 kcal per gram of egg mass scaled by hen-day Production Rate, so it rises directly with both Average Egg Weight and Production Rate but not with the bird's own weight. Metabolizable Energy is their sum, and Estimated Feed Intake divides that total by a fixed 2,800 kcal/kg diet-energy-density assumption, so anything that raises ME raises feed intake in direct proportion. Calcium Required, however, is calculated purely from Production Rate: a fixed 0.2 g/day maintenance term plus roughly 2.2 g of eggshell calcium per egg at full production, divided by an assumed 50% absorption efficiency -- it does not vary with Bird Weight or Average Egg Weight at all, treating eggshell calcium demand as constant per egg regardless of how big the bird or the egg actually is.

Because Calcium Required stays fixed while Estimated Feed Intake grows with Bird Weight (through the maintenance-energy term), Diet Calcium -- the percentage figure -- actually falls as Bird Weight rises: a heavier hen eating more total feed needs a smaller calcium percentage to deliver the same absolute number of grams. Available Phosphorus and Crude Protein follow the same maintenance-plus-production-rate structure as calcium, each with its own fixed per-egg contribution and absorption-efficiency divisor.