Metagenomic sequencing revealed the impact of GOS feeding on the rumen of dairy calves

Galacto-oligosaccharides (GOS) are prebiotic oligosaccharides synthesized from lactose, known to modulate the gut microbiota and improve immune and lipid metabolism. This study aimed to investigate the effect of GOS on the colonization of rumen microbiota in neonatal calves and elucidate its probiotic mechanisms. A completely randomized design was employed, selecting 14 newborn Holstein calves with similar birth dates and initial weights. These calves were randomly assigned to two groups (n = 7 each): a control group (CON) fed milk and a GOS group fed milk supplemented with 5 g/day/head GOS. The trial lasted for 28 days, and rumen fluid samples were collected on day 29.