Freeze-dried rumen fluid from goats shows storage potential for transplants

Researchers at Inner Mongolia Agricultural University freeze-dried rumen fluid from goats fed either alfalfa hay or corn stover diets. After reconstitution, the powders retained microbial activity and fermented exogenous substrates differently depending on the donor diet, per the study published in Frontiers in Microbiology. This suggests lyophilisation could standardise rumen fluid transplantation, which currently relies on fresh, perishable fluid.

Bottom line — The alfalfa-hay derived fluid produced 104mL gas in 24 hours, nearly 14% more than the corn-stover fluid, per the study.

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• Lyophilisation yields were about 6.3% regardless of diet, and culturable carbohydrate-utilising bacteria counts were around 3.8–3.9×10⁷ CFU/g, the researchers reported.
• The alfalfa-based powder was richer in propionate and valerate, while the corn-stover based powder had higher acetate, isovalerate, and an acetate-to-propionate ratio of 4.88 versus 3.49.
• Bacterial, fungal, and methanogen community structures differed significantly between the two groups, with corn-stover samples showing higher bacterial and fungal diversity (Shannon index), per the analysis.
• After reconstitution, both inocula fermented an exogenous substrate, but the corn-stover group produced more total volatile fatty acids (46.3mmol/L vs 42.8mmol/L), whereas the alfalfa group generated more gas and butyrate.
• The study’s authors argue that lyophilised rumen fluid could serve as a storable, standardised inoculum for rumen fluid transplantation in livestock.
• No fresh rumen fluid control was included, so the degree of fermentation function retained after lyophilisation could not be quantified, the authors acknowledged.

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