Use this estimate when the species, measurement method, body-size range, and units match the relationship implemented by the tool. It is most useful for screening, normalization, or comparing repeated measurements made under the same protocol.

Days elapsed

Number of days elapsed; must be greater than zero.

Final weight

Final body weight in kilograms.

Initial weight

Initial body weight in kilograms.

The implementation follows this calculation rule: Compute average daily gain as (final weight - initial weight) / days elapsed in kilograms per day; the result is signed, so weight loss yields a negative value.

Average daily gain

Average daily gain in kilograms per day; signed.

Allometric and livestock equations are empirical relationships, not direct measurements. Breed, age, sex, condition, hydration, posture, and the population used to fit the coefficients can produce systematic error. Preserve the input values and units so the result can be audited and recalculated.

Prefer a calibrated scale or direct laboratory measurement when available. For longitudinal work, pair the estimate with condition score, age, and repeated measurements collected by the same operator.

• Body Length Weight

  Estimate cattle weight in kilograms from body length and chest girth with the same-family length formula.

• Chest Girth Weight

  Estimate cattle weight in kilograms from the chest girth with the documented cubic approximation.

• Kleiber BMR

  Estimate basal metabolic rate across animals with Kleiber's law: BMR = 70 x bodyMass^0.75 kilocalories per day.