Apparent Crude Protein and Amino Acid Digestibility
Apparent ileal CP and AA digestibilities are shown
in Table 8. There were no differences in apparent ileal
CP digestibility among dietary treatments (P = 0.26).
Supplementing the NC diet with MP alone or in combination
with OA generally had no effect (P > 0.10) on
apparent ileal digestibilities of essential AA, except for
isoleucine (P = 0.0004) and histidine (P = 0.08), the
digestibilities of which were improved (Table 8). Of all
the dispensable AA, only the digestibility of aspartic
acid was increased (P = 0.02) due toMP+OA supplementation
compared with the C and NC diets. Nonetheless,
the current observation is in agreement with that of
Peter and Baker (2001) and Traylor et al. (2001) indicating
no improvement in AA utilization in growing pigs
fed soybean meal-based diets supplemented with MP.
Similarly, O’Quinn et al. (1997) and Valaja et al. (1998)
reported that MP supplementation had no effect on
apparent ileal and total-tract CP and AA digestibilities
in finishing pigs. However, others have found significant
improvements in AA utilization due to the addition
of MP to swine diets. For instance, Kemme et al. (1995)
and Kornegay et al. (1998) reported improvements (P
< 0.05) in AA digestibilities in growing pigs fed a corn–
soybean meal-based diet supplemented with MP.
The primary objective of supplementing swine diets
with MP is to facilitate the breakdown of the phytate
molecule so as to make the phytate-bound P available