some breeding companies have recommended 19 to 20 g of protein per day
for young commercial laying hens (Pullet and Layer
Management Guide; DeKalb Poultry Research, 2012).
Thus, many producers are feeding dietary protein levels
far in excess of the NRC (1994) recommended level of
16 g/hen per d in an attempt to maximize early egg
size. The present study was designed to evaluate the
effects of 3 series of protein levels on performance of
laying hens in 4 phases: (1) 18 to 22, (2) 23 to 32, (3) 33
to 44, and (4) 45 to 74 wk. The high, medium, and low
protein series were based on breeder management guide
recommendations of ± 2% CP.