Minimum broiler feed requirement (gram/day or gram/bird weight) for its survival and min. requirement for maximum weight gain

Note: Considering broiler is grown in ideal environment and in second scenario broiler is grown in this world with little

For reducing the cost of feed with minimal stress on bird and with maximum weight gain is there any specific or thumb rule formula for calculating minimum or maximum daily feed required (gram/day or gram/bird weight) that bird can fully utilize it nutrition without losing the excess of feed nutrition in feces.