DORB

Three levels of DORB (0, 3%, and 6%) were combined with two types of formulation (TAA or SIDAA) to yield a total of six treatments (Table 2).

The feed intake (Table 4) under TAA formulation was significantly reduced with 1.5% protein reduction (6% DORB; [T.sub.3]) compared to TAA control ([T.sub.1]) despite of limiting amino acid supplementation.

In contrast, under SIDAA treatments, since the diets were having same SIDAA levels, the birds probably did not increase their feed intake as the bird's amino acid requirement was met, subsequently resulting in lesser CP intake with 3% DORB inclusion itself.

The protein factor revealed significant deterioration of FCR with a protein reduction level of 0.75% and above during pre-starter phase and cumulatively, while during the starter and finisher phases, protein step down of 1.5% resulted in significant FCR depression compared to normal protein group (0% DORB) and protein reduction of 0.75% unit being mediocre remained similar to both normal protein group and 1.5% low protein group.