Table 1.

Factors influencing the rumen microbiota.

Factor	Host	Treatment	Results	References
Age	Goats	Days 0, 14, 28, 42, and 56	Prevotella, Treponema, Ruminococcus, and the unclassified family Prevotellaceae increase with the age of the kids.	[10]
	Lambs	Day 0, 3, 10, 20, 30, 45, 60, and 120	The rumen bacterial community and its functions were all affected by the age of the lambs.	[9]
Diet	Dairy calves	Milk-fed; milk plus starter concentrate fed	Feeding solid feed promoted a greater diversity of bacterial taxa known to degrade readily fermentable carbohydrates in the rumen. Milk-fed groups exhibit bacterial communities dominated by taxa that can utilize milk nutrients.	[22]
	Lambs	Adding alfalfa based on concentrate	The unclassified Lachnospiraceae, Treponema, and unclassified Ruminococcaceae were increased in starter supplemented with alfalfa groups during pre-weaning periods.	[48]
	Lambs	Linseed oil was added to the lambs’ diet	The relative abundance of Succinivibrionaceae and Veillonellaceae was higher in groups fed linseed oil before weaning, and the short-term addition of linseed oil to the diet of lambs in early life had a lasting effect on the community composition of rumen bacteria.	[5]
Genetic	Cattle bison	Transfer of rumen contents from bison to cattle	Inoculation with bison rumen contents alters the bison cattle rumen microbiome and metabolism.	[49]
	Beef cattle	A total of 709 beef cattle from three breeds were raised under the same feedlot conditions	Some rumen microbial features are heritable and may be influenced by host genetics.	[50]
Probiotics	Lambs	Saccharomyces cerevisiae CNCM I-1077 and their cultures	Live yeast supplements have induced the establishment of the eukaryotic families Trichostomatia, Neocallimastigaceae, and Fibrobacter succinogenes.	[51]
Rumen fluid transplantation	Lambs	Inoculation of lambs with adult sheep fresh rumen fluid	Fresh rumen fluid inoculation promoted the colonization of lamb by bacteria such as Succiniclasticum, Prevotella, and Proteobacteria S24-7.	[52]
Plant extract	Rumen-cannulated sheep	A total of 25 mg of resveratrol was added to a 300 mg high-concentrate or high-forage diet.	It reduces the abundance of Methanobrevibacter in the rumen fluid of lambs and increases the abundance of Prevotella and Desulfovibrio.	[53]