Use of combinations of commercial extracts from quebracho, oak and grape tannins to modulate in vitro ruminal fermentation

Autor: Toral, Pablo G., Hervás, Gonzalo, Belenguer, Álvaro, Árturo-Schaan, M., Mendoza, Alejandro G., Andrieu, D., Dupuis, E., Frutos, Pilar
Přispěvatelé: Toral, Pablo G., Hervás, Gonzalo, Belenguer, Álvaro, Frutos, Pilar, Toral, Pablo G. [0000-0002-1913-7707], Hervás, Gonzalo [0000-0002-0013-7459], Belenguer, Álvaro [0000-0002-9186-3463], Frutos, Pilar [0000-0002-4919-5094]
Jazyk: angličtina
Rok vydání: 2019
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Trabajo presentado al: XIIIth International Symposium on Ruminant Physiology (ISRP), P 68. 3-6 de septiembre de 2019. Leipzig (Alemania).
Despite their bad reputation among some nutritionists, it is nowadays widely accepted that tannins can be used as additives to modulate rumen fermentation. However, there is a void of information about which of the many types of tannins and at which doses may be more useful for a particular purpose. Furthermore, little is known about potential synergistic effects of different combinations of tannins. An in vitro assay with batch cultures of rumen microorganisms, using cannulated ewes as donors of rumen inocula, was performed to try to move forward on this subject. Commercial extracts of quebracho, oak and grape tannins, at doses selected from a previous study were combined following a simplex centroid design (in total, 10 combinations plus 1 control without tannins) and added to the incubation substrate (a total mixed ration based on alfalfa hay and concentrates, with 27% of starch and a F:C ratio of 40:60). Results suggested that there might be a synergistic effect of the combinations. For instance, none of the tannin extracts alone altered methane production, while some mixtures (mentioned below) did it, and the reductions of NH3-N, which would support a protection of dietary protein against ruminal degradation, were higher when combinations were used. Considering all the results together, we selected the next 3 treatments as the most convenient (doses are reported as % of incubated DM; real amounts after considering the simplex centroid design). Combination 1: 1.7% oak + 0.85% grape. This treatment induced lower gas and methane productions, ammonia-N concentration and molar proportion of minor volatile fatty acids (VFA; namely isobutyrate, isovalerate, valerate and caproate). Combination 2: 1.13% quebracho + 1.13% oak + 0.57% grape. Although this treatment affected negatively the ruminal disappearance of NDF (-8%), which would challenge its selection, it reduced gas and methane productions, ammonia-N concentration and molar proportion of minor VFA, as well as the acetate/propionate (A/P) ratio, and also increased the molar proportion of propionate. Combination 3: 0.57% quebracho + 2.27% oak + 0.28% grape. It reduced gas and methane productions, ammonia-N concentration, molar proportion of minor VFA, and the A/P ratio. This was the treatment with the strongest effect on NH3-N concentration (-22%). It also increased molar proportions of propionate and acetate, and it did not exert non-desirable effects on the in vitro ruminal fermentation parameters that were investigated. In closing, an appropriate combination of tannins may improve ruminant diet utilization while reducing methane emissions.
Databáze: OpenAIRE
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