Temporal microbial colonization on different forages is driven by the rumen environmental conditions

Area of Science:

• Rumen microbiology
• Animal nutrition
• Forage digestion

Background:

• The rumen hosts anaerobic microbes vital for feed digestion and volatile fatty acid (VFA) production.
• Rumen microenvironment significantly influences microbial community composition and function.

Purpose of the Study:

• To investigate how two distinct in vivo rumen conditions, alfalfa hay-rich (AHR) and corn stover-rich (CSR), impact fiber digestion and bacterial colonization.
• To compare the effects of AHR and CSR on alfalfa hay (AH) and corn stover (CS) forage degradation.

Main Methods:

• In situ incubation of AH and CS forages within AHR and CSR rumen environments for 48 hours.
• Analysis of rumen pH, VFA concentration, acetate-to-propionate ratio, and bacterial abundance.

Main Results:

• CSR conditions showed more stable pH, lower total VFA, and a higher acetate-to-propionate ratio compared to AHR.
• CSR significantly enhanced neutral detergent fiber and acid detergent fiber degradation for both AH and CS.
• CSR increased fibrolytic bacteria (e.g., Fibrobacter, Butyrivibrio) abundance on both forages, while AHR favored carbohydrate-degrading bacteria (e.g., Prevotella, Succinivibrio).

Conclusions:

• The rumen microenvironment critically affects microbial communities and forage breakdown efficiency.
• CSR conditions promote fibrolytic bacteria, enhancing forage degradation compared to AHR.
• Optimizing rumen pH and microbial composition can improve forage fermentation and animal performance.