An experiment was conducted to determine
the effect of diets with reduced CP and supplemental
amino acids on broiler performance, N
excretion, litter characteristics, and equilibrium NH3 gas
concentration. Results suggest that reducing CP (and
lysine) below 241 g/kg (13.7 g/kg lysine) in the diets fed
during the first 3 wk may slightly increase feed:gain and
therefore may not be advisable. During the period 22 to
43 d of age there were no significant differences in
weight gain and BW at 6 wk of age when reducing CP
from 215 g/kg (11.5 g/kg lysine) to 196 g/kg (11.3 g/kg
lysine), but feed intake and feed:gain ratio increased.
However, reducing CP did cause equilibrium NH3 gas
concentration and litter N to decline by 31 and 16.5%,
respectively. Both of these advantages will improve air
quality within the housing facility and possibly reduce
heating costs during winter associated with higher
ventilation rates required to reduce elevated NH3 gas
concentrations.