Effect of Yucca schidigera on ruminal fermentation and nutrient digestion in heifers.

In a replicated 3 x 3 Latin square experiment, six heifers (443 +/- 6.1 kg) fed a 61% barley grain:39% alfalfa silage diet (DM basis) were given intraruminal doses of powdered Yucca schidigera (YS). Doses of 0 (control), 20, or 60 g/d were given at 0800 daily. Ruminal content was sampled 0, 2, 4, and 6 h after dosing. Acidity, concentrations of reducing sugars, free amino acids, and peptides in the rumen were not affected (P > .05) by YS. Relative to control, ruminal ammonia concentration was reduced (P < .05) 2 h after YS dosing. Ruminal propionate concentration was increased (P < .05) by YS. Protozoal numbers in the rumen were lower (P < .05) with YS than without. Yucca did not affect (P > .05) rate or extent of in situ DM degradability. Fibrolytic, amylolytic, and proteolytic activities in ruminal contents were similar among treatments (P > .05). Dry matter intake, apparent digestibilities of DM, NDF, and CP, nitrogen balance, and microbial protein synthesis in the rumen were not affected (P > .05) by treatment. The effect of YS on ruminal ammonia concentration likely resulted from a decreased concentration of protozoa and, presumably, from ammonia binding by YS. The effect on ruminal propionate was probably a result of a selective inhibitory effect of YS on rumen microbial species.

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title: Effect of dietary Yucca schidigera extract on rumen and blood profiles of steers fed concentrate- or roughage-based diets
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title: Influence of yucca extract on ruminal metabolism in cows.
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title: 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 ammonia-binding capability was retained after autoclaving and was decreased slightly following dialysis. Acid-precipitated 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 ES1 extended its lag phase, while growth of Butyrivibrio fibrisolvens SH13 was abolished. The growth of Prevotella (Bacteroides) ruminicola B(1)4 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.

title: The Rumen Protozoa
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title: Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition.
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title: Effect of formaldehyde-treated barley or escape protein on the ruminal environment and digestion in steers
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title: Automated simultaneous determination of ammonia and total amino acids in ruminal fluid and in vitro media.
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title: Effect of diet, digesta processing, freezing and extraction procedure on some polysaccharide-degrading activities of ruminal contents
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title: Investigation of chromium, cerium and cobalt as markers in digesta. Rate of passage studies.
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title: The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage
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title: Comparison of sweet white lupin seed, canola meal and soybean meal as protein supplements for lambs
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title: The effect of feed intake and body weight on purine derivative excretion and microbial protein supply in sheep.
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title: Synthesis of microbial protein in ruminally cannulated cows fed alfalfa silage, alfalfa hay, or corn silage.
abstract: Six ruminally cannulated cows were used in an experiment with a 3 x 3 Latin square design. Three all forage diets-alfalfa silage, alfalfa hay, or corn silage plus 2.2% urea (DM basis)-were fed for ad libitum intake four times daily. The microbial protein marker 15NH3 and the liquid marker Cr-EDTA were infused continuously into the rumen for 72 and 48 h, respectively; the solid marker, Yb-labeled forage, was dosed into the rumen twice daily for 60 h. Pool sizes of ruminal NAN were determined by emptying the rumen. Proportions of bacterial N formed from NH3 were 57, 46, and 82% for the alfalfa silage, alfalfa hay, and corn silage diets, respectively. For all diets, flows of microbial NAN with the liquid and solid phases were about equal. Although feed NAN in the liquid pool was only 12% of ruminal feed NAN, 30% of feed NAN that escaped the rumen flowed with the liquids. Flow of microbial NAN was highest for corn silage (243 g/d) and lowest for alfalfa hay (212 g/d); microbial NAN represented 50% (alfalfa silage and hay) and 76% (corn silage) of total NAN flow. Proportions of NAN intake that were degraded in the rumen were 61, 56, and 57% for alfalfa silage, alfalfa hay, and corn silage (without urea N), respectively; these values were lower than those reported by the NRC. Total flows of NAN from the rumen were 472, 424, and 321 g/d for the alfalfa silage, alfalfa hay, and corn silage diets, respectively. Use of liquid (Cr-EDTA) and solid (Yb) markers to compute the rate of passage of microbial protein proved to be less variable than regression of 15N enrichment of bacterial NAN over time.

title: Role of rumen protozoa in nitrogen digestion in sheep given two isonitrogenous diets.
abstract: 1. The effect of protozoa on digestion in the rumen was studied using either defaunated or faunated sheep. 2. Six wethers, each fitted with rumen and simple duodenal cannulas, were given two isonitrogenous diets containing either lucerne (Medicago sativa) hay (diet L) or sodium hydroxide-treated wheat straw (diet S). The diets were given in eight equal portions per day at 3-h intervals. The mean intake of dry matter, 53 g/kg body-weight0.75 per d, was similar for the two diets and each diet had a similar digestible organic matter content. Diet L promoted a large protozoal population and was rich in nitrogen sources of low rumen-degradability, while diet S supported a smaller protozoal population and was rich in rumen-degradable N. 3. Digesta flow at the duodenum was estimated by means of a dual-marker technique using chromium-mordanted lucerne hay and polyethylene glycol as markers. The microbial flow at the duodenum was estimated using diaminopimelic acid (DAPA), nucleic-acid purine bases (PB) and 35S incorporation simultaneously. The different microbial markers were compared in the defaunated sheep. Protozoal N contribution was estimated in faunated sheep. 4. Defaunated sheep had lower rumen ammonia concentrations and molar proportions of butyric acid than faunated sheep, but they had higher molar proportions of propionic acid. 5. Rumen organic matter digestion was reduced by defaunation, but this decrease was compensated for by increased intestinal digestion. 6. There was a net increase of N flow (approximately 10 g/d) between mouth and duodenum in defaunated sheep. This was explained by increases in both microbial and dietary N flows from the rumen compared with faunated sheep. 7. The influence of protozoa on solid- and liquid-phase retention times in the rumen is discussed, as well as the protozoal contribution to microbial N flow in the duodenum of faunated sheep.

title: Changes in saponin content and composition during the ensilage of alfalfa (Medicago sativa L.)
abstract: Two varieties of alfalfa ( Medicago sativa L.) were ensiled under laboratory conditions after being treated with formic acid or after wilting for different times. Intact saponins, using an HPLC method, were determined in the starting material and after ensiling. The presence of two saponins were detected and measured in the experiment using the variety Hodoninka and three saponins in the second experiment using the variety Palava. Soyasaponin I was present in both varieties, whilst the two other saponins, designated as saponin A and saponin B, had chromatographic properties consistent with glycosides, of medicagenic acid. Significant decreases in saponin concentrations were observed after ensiling varying from 12% to 100%. Soyasaponin I was found to be relatively stable, while saponin A was not detected after the first week of ensiling. Treatment with formic acid stabilised saponin B and soyasaponin I for the variety Palava in contrast to the other treatments.

title: Influence of foliage from African multipurpose trees on activity of rumen protozoa and bacteria.
abstract: Samples and extracts of foliage from African multipurpose trees were screened for their effects on rumen protozoa and bacteria with a view to predicting their safety as feed supplements and for identifying species with potential antiprotozoal activity. The species tested were Acacia aneura, Chamaecytisus palmensis, Brachychiton populneum, Flindersia maculosa, Sesbania sesban, Leucaena leucocephala and Vernonia amyedalina. Antimicrobial effects were mild except for S. sesban, which was highly toxic to rumen protozoa in vitro, and A. aneura, which was toxic to rumen bacteria. The antiprotozoal factor in S. sesban was apparently associated with the fraction of the plant containing saponins. When S. sesban was fed to sheep, protozoal numbers fell by 60% after 4 d, but the population recovered after a further 10 d. In vitro experiments demonstrated that washed protozoa from later times were no more resistant to S. sesban than on initial exposure, suggesting that other micro-organisms, probably the bacteria, adapted to detoxify the antiprotozoal agent. Thus S. sesban may be useful in suppressing protozoa and thereby improving protein flow from the rumen, but only if the bacterial metabolism of the antiprotozoal factor can be avoided.

title: Effects of Yucca Shidigera extract on feed utilization by equine weanlings
abstract: Reports in the literature suggest that dietary supplementation with water soluble extract of Yucca shidigera can reduce biological ammonia emissions from livestock in confinement. Because a reduction in environmental ammonia in equine housing facilities would benefit both human and animal health, the effects of Y. shidigera extract(YSE) on equine nitrogen metabolism were examined in this experiment. The addition of 100 ppm Y. shidigera extract to a 75% hay, 25% grain, lysine-deficient feed resulted in a significant increase in fecal nitrogen excretion by weanling Thoroughbreds and therefore a decrease in the apparent digestibility of dietary nitrogen. The proportion of fecal nitrogen that was water soluble increased (p A reduction in ambient ammonia in equine housing facilities may be desirable from several health perspectives. Environmental ammonia is noxious to both animals and man, and may provoke respiratory irritation and compromise. 6. , 29. Soluble compounds extracted from Yucca shidigera have recently been reported to reduce airborne ammonia concentrations in livestock production facilities when added directly to manure or incorporated into livestock feeds. 3. , 29. Althohgh free ammonia production may increase in the presence of a water soluble extract of Y. shidigera, ammonia in digesta and fecal materials apparently binds to the steroid saponins (sarsapogenin, smilagenin, hecogenin) found in the extract. 19 The most convenient method for introducing saponins into equine waste would be via the feed. Dietary saponins are apparently neither absorbed nor metabolized by ruminants or nonruminants, 7. , 10. , 27. although their ingestion may be associated with improved feed utilization and rates of growth. 18. , 27. However, it is not clear whether increased production efficiency resulted from metabolic effects attributable to saponins or from a reduction in animal stress accompanying a reduction in ambient ammonia concentrations. In the equine, growth efficiency is dependent on effective reutilization of a portion of the cecal and colonic ammonia derived from the hydrolysis of urea secreted into the intestine 11 Significant binding of ammonia to saponins within the cecum and colon could impair nitrogen economy and be detrimental to growing horses. On the other hand, increased urease hydrolysis of recycled urea could compensate for a saponin-induced reduction in the free ammonia content ofdigesta. Live yeast culture preparations may stimulate urease activity in young horses; 13. , 14. combined supplementation with both saponins and yeast culture might maintain efficient utilization of dietary nitrogen and tissue growth while reducing ammonia emissions. This experiment was undertaken to determine whether supplementation with Y. shidigera extract (YSE) affects the digestibility of dietary nutrients, the production of fecal ammonia, the efficiency of utilization of dietary nitrogen or growth in young horses. In order to ease the detection of any responses, particularly in the absence of any dose-response data, nitrogen-replete but lysine-deficient diets were used. The possibility that supplemental live yeast culture (YC) added with the saponins-emiched extract might beneficially interact with any effects of the saponins was also examined.