in vitro DM digestibility of the corn straw. Untreated
corn straw cannot be included in high quantities
in lactating cow rations (Oji et al. 1977; Wilkinson,
1984). But, because in vitro DM digestibility of the
T-CS was similar to that of wheat hay (62.1 and 63.6%,
respectively), it motivated the use of T-CS as wheat
hay replacer in TMR fed to lactating cows. The control
TMR contained 3.7% more OM, 6.2% less NDF, 7.1%
less roughage NDF, and similar protein and fat content
to that of the T-CS TMR. In vitro DM digestibility was
3.2% higher in the control TMR than the T-CS TMR
(Table 1).