Pellets Inoculated with Bacillus amyloliquefaciens H57 Modulates Diet Preference and Rumen Factors Associated with...

Area of Science:

• Ruminant nutrition
• Microbiology
• Animal science

Background:

• Probiotics can influence gut function and animal behavior.
• Understanding the pre- and post-ingestive effects of probiotics is crucial for optimizing their application in livestock.

Purpose of the Study:

• To investigate the impact of Bacillus amyloliquefaciens strain H57 (H57) on ruminal fermentation.
• To determine if H57 influences appetite control mechanisms through post-ingestive feedback.
• To differentiate between the pre- and post-ingestive effects of H57 on steer behavior and ruminal parameters.

Main Methods:

• A 4x4 Latin square design with four rumen-fistulated steers.
• Four feeding treatments were used to separate intra-ruminal (post-ingestive) and oral (pre-ingestive) administration of H57.
• Rumen fluid was sampled at intervals post-feeding, and steer preference for H57-inoculated pellets was assessed.

Main Results:

• Steers showed a significant preference for pellets inoculated with H57 over control pellets (p < 0.001).
• Feeding H57 pellets resulted in higher ruminal pH, increased molar proportions of iso-butyrate and iso-valerate (p < 0.05), and a trend towards greater ruminal ammonia concentrations (p < 0.1).
• The study found no significant difference in diet preference based on the treatment protocol used to separate pre- and post-ingestive effects.

Conclusions:

• Bacillus amyloliquefaciens strain H57 positively influences ruminal fermentation parameters and is preferred by steers.
• Both pre- and post-ingestive factors contribute to the effects of H57, with pre-ingestive preference being a strong driver.
• Further research may elucidate the specific mechanisms by which H57 modulates ruminal fermentation and appetite.