The formulas to calculate manure production for chickens are:

1. For Layer:

\[ W_m = 0.075 \cdot N_a \cdot N_d \]

2. For Broiler:

\[ W_m = 0.025 \cdot N_a \cdot N_d \]

Where:

• \(W_m\) is the weight of manure produced in kilograms (kg).
• \(N_a\) is the number of birds.
• \(N_d\) is the number of days.