Therefore, the factors which effect the rumen microbial growth should change the nucleic acid base concentrations in rumen fluid.
In conclusion, there is insufficient information about the changes of bacteria nucleic acid bases in rumen fluid of different diets and lactation stages from previous studies.
The rumen nucleic acid bases were extracted from freeze-dried samples using perchloric acid, as described by Zinn and Owens .
A multiple regression was applied using the STEPWISE method of REG procedure of SAS to develop equations to predict microbial nucleic acid bases in the rumen.
The experimental data used for model development occurred over a wide range and the data of OBCFA contents were more variable than the nucleic acid bases value in rumen (Table 3).
The interaction of dietary F:C ratios and time of sampling significantly influenced the nucleic acid bases concentrations with the exception of guanine bases (Table 4).
The variations of nucleic acid bases in rumen with lactation stages and time of sampling are shown in Table 5.
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