Évolution de la concentration en protozoaires et en ammoniaque de fermentations ruminales avec un substrat supplémenté en extraits de plantes à saponines

Yucca schidigera et Quillaja saponaria sont des plantes à saponines (PAS) utilisées en alimentation des ruminants pour optimiser la gestion de l’ammoniaque (NH3) dans le rumen, en particulier lorsque les rations sont riches en azote soluble (e.g. mise à l’herbe, manque d’énergie). Les données sur d’autres PAS sont rares bien que ces métabolites secondaires amphiphiles sont présentes dans beaucoup de végétaux. L’objectif de ce travail était de déterminer in vitro l’effet d’extraits de plantes à saponines sur l’évolution du nombre de protozoaires et sur la concentration en NH3 du fluide ruminal

Caractérisation d’extraits de plantes à saponines par analyse chimique (HPLC-MSn) et activité hémolytique

National audienc

Potential of extracts from Saponaria officinalis and Calendula officinalis to modulate in vitro rumen fermentation with respect to their content in saponins

Saponins have the potential to favorably modulate rumen fermentation, but there is generally a lack of the chemical structures associated with the described effects. The activity of extracts from Calendula officinalisand Saponaria officinalis in the rumen was evaluated in vitro. The S. officinalis root extract, reduced CH4production by 8.5% and increased total VFA concentration by 25.2%. C. officinalis and S. officinalis root extracts and the S. officinalis aerial part extract decreased the acetate to propionate ratio from 8.6 to 17.4%, according to the extract. An HPLC-ELSD analysis indicated that the saponin content ranged from 43.6 to 57.6 mg/g of dry matter (DM) in the C. officinalis extracts and from 224.0 to 693.8 mg/g of DM in the S. officinalis extracts, expressed as the hederacoside C equivalent. Identification of the saponin compounds present in the extracts by HPLC–MSn suggested that the saponin profile modulated the biological activities, showing the importance of determining the structure of saponins when evaluating extracts

Effects of in vitro and in vivo dietary supplementation with saponins on rumen fermentation with particular reference to volatile fatty acids, ammonia and methane

Résumé publié dans : Advance in Animal Biosciences, Janv. 2013; 4(2):577. doi:10.1017/S2040470013000125.International audienc

Activities of extracts from saponin-containing plants on sheep erythrocytes, Tetrahymena pyriformis and Rumen protozoa

As the effects of saponins in the rumen are due to their membrane-disrupting ability on protozoa, the activities of extracts from saponin containing plants were determined on erythrocytes, Tetrahymena pyriformis and rumen protozoa. Inhibition of Tetrahymena pyriformis were found to be correlated (R2=0.54) with 50% hemolysis. The extracts supplemented to a standard feed, showed null to remarkable in vitro activity on rumen protozoa. With -51% and -41% protozoa inhibition, Primula veris and Chenopodium quinoa might have the potential to improve ammonia utilization in ruminants, meaning less excreted nitrogen and less environmental impact

Effect of several saponin containing plant extracts on rumen fermentation in vitro, Tetrahymena pyriformis and sheep erythrocytes

Among the nutritional solutions developed since in-feed antibiotics were banned by the European Union in 2006, extracts from plants with high saponin content have shown the capacity to modulate rumen fermentation. Most previous studies have focused on the effects of Yucca schidigera and Quillaja saponaria. This study was designed to evaluate i) the effects of extracts obtained from 11 saponin-containing plants and monensin on rumen fermentation patterns in vitro at 417 and 2.0 mg/L, respectively, and ii) the capacity of hemolytic test and inhibition of Tetrahymena pyriformis to model the effect of saponin-containing plant extracts on rumen protozoa. Plants belonging to 8 different families were investigated to evaluate a high diversity of saponin compounds. Total gas and methane productions were numerically lower with extract of Saponaria officinalis compared to control (-3.0 and -9.0%, respectively). The effect was more pronounced with monensin (-25.5 and -31.7%, p<0.05, respectively). Ammonia (NH3) and protozoa patterns varied among the extracts during in vitro incubations, e.g. from -22.6% (p<0.05) for Y. schidigera extract to -50.7% (p<0.05) for Primula veris extract, with respect to the protozoa number. Extracts from Primula veris, Chenopodium quinoa and Gypsophila paniculata mitigated significantly NH3 production by more than 26% (p<0.05) which, in our experimental conditions, was better than the results obtained with monensin and extracts from Y. schidigera and Q. saponaria. Statistically significant positive correlations were found between hemolytic capacity and inhibition of T. pyriformis (Pearson coefficient = 0.55, p<0.05) and between protozoa number and NH3 concentration during in vitro rumen incubation (Pearson coefficient = 0.56, p<0.05). Neither hemolytic capacity, nor inhibition of T. pyriformis, nor the content in total saponins estimated by gravimetric method was correlated to the inhibition of rumen protozoa. These parameters did not model the effect of extracts from different saponin containing plants on rumen protozoa number. However, the results suggest that by-products containing saponins from food (C. quinoa) and horticultural (G. paniculata) industries could be investigated as feed additives to improve nitrogen utilization by ruminants