To convert pounds to ounces, you can use the conversion factor that 1 pound equals 16 ounces.
To convert 815 pounds per day to ounces per day, you can multiply by 16:
\[ 815 \text{ pounds/day} \times 16 \text{ ounces/pound} = 13,040 \text{ ounces/day} \]
Thus,
\[ 815 \text{ pounds/day} = 13,040 \text{ ounces/day}. \]