The data (Table 4) show that by paying for 2% more
protein, the producers could receive about 2.56% more
eggs. The eggs would each be 2.84 g heavier and produced
from 127 g less feed per kg of eggs. These data
demonstrate the difficulty in applying a least cost linear
programming methodology to the formulation of
feeds for commercial egg layers. Least cost diets may be
formulated for each protein level, but additional analysis
is necessary to reconcile increases in protein level
cost and increased returns. Feed conversion ratio was
improved by 3% more CP from 38 to 60 wk of age (1.91
vs. 1.98), with the largest response occurring from 51
to 60 wk of age (1.89 vs. 1.98; Novak et al., 2008). This
is in contrast to reports of improved feed conversion
ratio when feeding diets with lower CP while maintaining
minimum levels of essential amino acids (Penz and
Jensen, 1991; Novak et al., 2006). The important difference
is in how the diets were formulated: in the present
study, the protein to essential amino acid ratio minimums
were maintained. In the Penz and Jensen (1991)
and Novak et al. (2006) studies, protein decreased in
proportion to essential amino acid levels.