The industry continues
to feed more protein and amino acid intake per
day than suggested by the NRC (1994) because of concern
of underfeeding for optimum hatching egg production and chick quality. Feeding breeders elevated levels
of dietary amino acids and protein is a major reason
for increased egg size. Research from Salas et al. (2010)
suggests that breeders producing to their genetic potential
for hatching eggs and egg mass may actually
produce smaller eggs. Breeders producing smaller eggs
may be able to partition more nutrients toward producing
more total eggs. Overfeeding amino acids and CP to
breeders in production may also elevate skeletal tissue
protein deposition (Ekmay et al., 2011). An increase
in skeletal protein deposition during egg production
would increase the daily ME requirement for maintenance
and decrease the amount of energy that would be
partitioned for egg production. Previous research has
also shown that high levels of dietary CP may negatively
affect fertility and hatchability. Pearson and Herron
(1982) reported that breeders consuming 27 g of
protein per d produced an increased number of dead
and deformed embryos and also reported a decrease
in hatchability of fertile eggs compared with breeders
consuming 23.1 g of protein/bird per d. Lopez and Leeson
(1995) showed a decrease in fertility in hens fed
high CP levels (16% vs. 10 to 14%). The objective of
the study reported here was to determine the digestible
amino acid requirement of each amino acid for product
(egg mass plus BW change/d) and feed conversion (g of
feed/ g product) for broiler breeder hens for the period
around peak egg production.