Effects of Two Halophytic Plants (Kochia and Atriplex) on Digestibility, Fermentation and Protein Synthesis by Ruminal Microbes Maintained in Continuous Culture

Eight continuous culture fermenters were used in a completely randomized design to evaluate various nutritional values of Kochia (Kochia scoparia) compared with Atriplex (Atriplex dimorphostegia). Dried and pelleted samples (leaves and stems) provided substrate for metabolism by ruminal microbes maintained in a continuous culture fermentation system. Results indicated that there were no differences (p>0.05) in dry matter (DM) and crude protein (CP) digestibility between the two halophytic plants. Atriplex had higher (p<0.05) organic matter (OM) digestibility compared with Kochia. Neutral detergent fiber (aNDF) digestibility of Atriplex (411 g/kg) was higher (p<0.05) than that of Kochia (348 g/kg), however acid detergent fiber (ADF) digestibility was higher (p<0.05) in Kochia compared with Atriplex (406 vs. 234 g/kg). There were no differences (p>0.05) between the two halophytic plants in molar proportion of acetate and propionate, but the concentration of butyrate and valerate in Kochia were about two fold of Atriplex (p<0.05). When Kochia provided substrate to the microbes, protein synthesis was higher (p<0.05) compared with feeding Atriplex (5.96 vs. 4.85 g N/kg of OM truly digested). It was concluded that Kochia scoparia and Atriplex dimorphostegia had similar digestibility of DM and CP. It appears that these halophytic plants may not have enough digestible energy for high producing ruminants.