Differences between the three roughages and the two types of TMR fed to 21 pairs of lactating cows with respect to chemical composition (Tables 1 and 3), in vivo digestibility and rumen pH (Table 4), were tested for significance by F-test using JMP-5 software (SAS, 1996). Tukey–Kramer test (SAS, 1996) was used for comparison between means.