Humic acid supplementation modulates ruminal and fecal microbial communities in lamb

Area of Science:

• Animal Science
• Microbiology
• Gastroenterology

Background:

• The gastrointestinal microbiome plays a crucial role in animal health and productivity.
• Modifying the microbiome with feed additives is a promising strategy to enhance animal performance.
• Humic acids (HA) are potential candidates for modulating gut health.

Purpose of the Study:

• To investigate the effects of humic acids (HA) on the ruminal and fecal microbiomes of lambs.
• To assess the potential adherence of HA to the ruminal mucosa.
• To evaluate HA as a functional feed additive for ovine gut health.

Main Methods:

• Twenty weaned lambs were divided into control and HA-supplemented groups.
• Humic acids were administered orally at 500 mg/kg BW/day for 56 days.
• Ruminal and fecal samples were analyzed using 16S rRNA gene sequencing.
• Ruminal mucosal tissue was examined via histology and scanning electron microscopy (SEM).

Main Results:

• HA supplementation increased the relative abundance of Bifidobacterium in the ruminal microbiome.
• HA decreased Lachnospiraceae CAG-127 in the ruminal microbiome.
• In the fecal microbiome, HA increased Acutalibacteraceae UBA5905 and Lachnospiraceae VUNI01, while decreasing Campylobacterales and Acutalibacteraceae CAG-180.
• Histology and SEM confirmed no adherence of HA to the ruminal mucosa.

Conclusions:

• Humic acids effectively modulated the ruminal and fecal microbiomes in lambs.
• HA supplementation reduced the abundance of potentially harmful bacteria and increased beneficial ones.
• Humic acids show potential as a functional feed additive for improving ovine gut health and productivity.