Influence of Yucca shidigera extract on ruminal ammonia concentrations and ruminal microorganisms

Abstract

An extract of the desert plant Yucca shidigera was assessed for its possible benefit in ruminal fermentation. The extract bound ammonia in aqueous solution when concentrations of ammonia were low (up to 0.4 mM) and when the extract was added at a high concentration to the sample (20%, vol/vol). The apparent ammoniabinding capability was retained after autoclaving and was decreased slightly following dialysis. Acidprecipitated extract was inactive. No evidence of substantial ammonia binding was found at higher ammonia concentrations (up to 30 mM). When Y. shidigera extract (1%, vol/vol) was added to strained rumen fluid in vitro, a small (6%) but significant (P < 0.05) decrease in ammonia concentration occurred, apparently because of decreased proteolysis. Inclusion of Y. shidigera extract (1%, vol/vol) in the growth medium of the rumen bacterium Streptococcus bovis ESI extended its lag phase, while growth of Butyrivibrio fibrisolvens SH13 was abolished. The growth of Prevotella (Bacteroides) ruminicola B14 was stimulated, and that of Selenomonas ruminantium Z108 was unaffected. Protozoal activity, as measured by the breakdown of 14C-leucine-labelled S. ruminantium in rumen fluid incubated in vitro, was abolished by the addition of 1% extract. The antimicrobial activities were unaffected by precipitating tannins with polyvinylpyrrolidone, but a butanol extract, containing the saponin fraction, retained its antibacterial and antiprotozoal effects. Saponins from other sources were less effective against protozoa than Y. shidigera saponins. Y. shidigera extract, therefore, appears unlikely to influence ammonia concentration in the rumen directly, but its saponins have antimicrobial properties, particularly in suppressing ciliate protozoa, which may prove beneficial to ruminal fermentation and may lead indirectly to lower ruminal ammonia concentrations.

Ferric citrate, nitrate, saponin and their combinations affect in vitro ruminal fermentation, production of sulphide and methane and abundance of select microbial populations

“…Furthermore, saponin may also inhibit the growth and activity of certain rumen microbial species that contribute to protein degradation (e.g. Streptococcus bovis, Butyrivibrio fibrisolvens and Prevotella bryantii) and, hence, lowering the extent of proteolysis and deamination (Wallace et al 1994). The anti-ammoniagenesis effect of ferric citrate was also noted in another set of in vitro ruminal cultures (Wu et al, unpubl.…”

“…The lower ammonia concentration in the three-way combination compared to the saponin-nitrate combination also suggests an additive effect of saponin and ferric citrate in counteracting ammoniagenesis caused by nitrate. The anti-ammoniagenesis effect of saponin is due to its inhibition to protozoa, which engulf bacteria and degrade microbial protein (Kurihara et al 1968), and binding to ammonia through its the sugar moiety (glycon) (Wallace et al 1994), thus decreasing the concentration of free ammonia in the cultures. Furthermore, saponin may also inhibit the growth and activity of certain rumen microbial species that contribute to protein degradation (e.g.…”

Effects of a selection of additives on in vitro ruminal methanogenesis and in situ and in vivo NDF digestibility

“…Nutritional strategies aimed at reducing CH4 production include the use of additives such as essential oils (Evans & Martin 2000), saponins (Santoso et al 2004), tannins (Carulla et al 2005;Grainger et al 2009), organic acids (McAllister & Newbold 2008) and probiotics such as live yeast (Lynch & Martin 2002;Newbold & Rode 2006). The inclusion of essential oils, tannins and saponins in ruminant diets has received wide interest, as these additives decrease rumen protozoal counts (Wallace et al 1994;Hart et al 2008) and methanogenesis (Hess et al 2003(Hess et al , 2004Santoso et al 2004). However, these beneficial effects could be offset by a decrease in total VFA production and feed digestibility (Busquet et al 2006;Martinez et al 2006).…”

Effect of steroidal saponin from Yucca schidigera extract on ruminal microbes

“…Consistently lower acetate to propionate ratios associated with YE supplementation both in vitro (Grobner et al 1982;Wang et al 1999a) and in vivo (Kil et al 1994;Hristov et al 1999) also imply that rumen microbial populations were affected by YE. Wallace et al (1994) reported species-dependent effects of YE on pure cultures of ruminal bacteria (Butyrivibrio ®brisolvens SH13, Selenomonas ruminantium Z108, Streptococcus bovis ES1 and Prevotella ruminicola) and suggested that YE may affect bacteria with Gram-positive ultrastructure more than it does Gramnegative organisms. In that study, however, the effects reported were those arising on initial exposure of the bacteria to YE.…”