6.1 Calculations and Definitions

Use these definitions to reconcile your report values with your stock movements, measurements, and targets. Keep Company, House, and dates consistent when comparing results.

Population and survival

Daily closing population is the historical batch stock balance at day end in the selected Company/House scope. Transfers have source and destination movements; a same-batch valuation Repack does not create new animals.

Period survival is:

exposure = opening animals + animals entering the scope
survival % = 100 × (exposure − classified deaths) / exposure

Sales and separately classified culling are departures rather than deaths. House entrants include animals transferred into that house. Invalid stock corrections or incomplete transformations can make the denominator unavailable. This is a period operational measure, not lifetime cohort survival.

Biological age and targets

age day = measurement/report day − verified Hatch/Birth Date
feed target kg = sum(daily closing animals × exact-age intake g / 1,000)
hen-day yield % = 100 × configured eggs / sum(daily closing hens)
yield target % = sum(daily closing hens × daily yield target %) / sum(daily closing hens)

Age zero is the Hatch/Birth Date. Target lookup is exact, with no interpolation. Feed/yield targets need a target for every day with positive population. Invalid negative balances or missing exposure do not produce partial targets. Hen-day yield requires an all-female laying profile.

Weight, FCR, and variance

biomass gain kg = eligible population × (ending average kg − opening average kg)
interval FCR = interval feed kg / positive biomass gain kg
variance = actual − target
variance % = 100 × (actual − target) / target

The simple interval formula requires a valid stable population and supported measured interval. Weight targets use measurement age; FCR targets use ending measurement age. Several eligible intervals aggregate feed and biomass rather than averaging FCRs. Percentage variance is unavailable for zero targets. Egg-yield variance is actual minus target in percentage points.

Blank targets mean unspecified; explicit zero targets remain valid. Missing data is unavailable, not zero. Lower feed can indicate underfeeding, so variance signs do not automatically establish good or bad performance.

See Target Comparisons for full eligibility details.