- Literature suggests that dietary crude protein (CP) reduction below the currently established commercial levels is accompanied by performance loss. However, in many cases limitations in the experimental setups may explain these effects on performance.
- Several published trials in which dietary CP was successfully reduced can serve as best practice examples.
- Establishing a phase feeding program is prerequisite for successful CP reduction.
- With respect to the grower/finisher phase and to the entire production cycle best practice examples suggest SID Met+Cys : SID Lys: ≥ 75 %, SID Thr : SID Lys: ≥ 64 % (increasing ratio to ≥70 % under low protein conditions might be relevant), SID Val : SID Lys: ≥ 80 %, SID Ile : SID Lys: ≥ 70 %, SID Arg : SID Lys: ≥ 110 %, and SID Glyequivalent : SID Lys: ≥ 112 %.
- Nitrogen utilization can be optimized by CP reduction but in order to maximize N-utilization, performance might be compromised.
- Dietary CP reduction reduces water intake and litter volume, improves litter quality and footpad health, amongst other benefits which should be included in the economic assessment of CP reduction in commercial settings.