Abstract:
Objective Effect of Astragalus membranaceus straw on in vitro rumen digestion of cattle was investigated to determine the applicability of Astragalus membranaceus straw in ruminant feed.
Methods An experiment was divided into two groups of corn stalk meal (CON group) and Astragalus membranaceus straw meal (AM group) with three repeats per group. Gas production in the in vitro fermentation at 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 36, 40, 44, 48, 56, 64, and 72 h were monitored. At 72 h, the terminal pH and contents of ammonia nitrogen, volatile fatty acids, and dry matters digestibility were measured.
Results (1) In AM group, the amounts of gas production at all sampling points during the fermentation were significantly reduced but the gas production rate was increased (P<0.01). (2) In AM group, the acetic acid content and the acetic acid to propionic acid ratio were significantly higher (P<0.01), but the contents of ammonia nitrogen, total volatile fatty acid, propionic acid and butyric acid were lowered significantly (P<0.05). (3) No significant differences on pH and dry matter digestibility were observed between CON and AM (P>0.05).
Conclusion Astragalus membranaceus straw decreased the total rumen gas production, and had a certain regulatory effect on rumen acetic acid fermentation, which indicated Astragalus membranaceus straw had the potential to be used as feed and feed additive for ruminants.