Six plant sources of hydrolyzable tannins (HT) or HT and condensed tannins (CT; designated as HT1, HT2, HT3, HT + CT1, HT + CT2, and HT + CT3) were evaluated to determine their effects in vitro on ...CH4 production and on ruminal archaeal and protozoa populations, and to assess potential differences in biological activities between sources containing HT only or HT and CT. Samples HT1, HT2, and HT3 contained only HT, whereas samples HT + CT1, HT + CT2, and HT + CT3 contained HT and CT. In experiment 1, in vitro incubations with samples containing HT or HT + CT resulted in a decrease in CH4 production of 0.6 and 5.5%, respectively, compared with that produced by incubations containing the added tannin binder polyethylene glycol-6000. Tannin also suppressed the population of methanogenic archaea in all incubations except those with HT2, with an average decrease of 11.6% in HT incubations (15.8, 7.09, and 12.0 in HT1, HT2, and HT3) and 28.6% in incubations containing HT + CT (35.0, 40.1, and 10.8 in HT + CT1, HT + CT2, and HT + CT3) when compared with incubations containing added polyethylene glycol-6000. The mean decrease in protozoal counts was 12.3% in HT and 36.2% in HT + CT incubations. Tannins increased in vitro pH, reduced total VFA concentrations, increased propionate concentrations, and decreased concentrations of iso-acids. In experiment 2, when a basal diet was incubated with graded levels of HT + CT1, HT + CT2, and HT + CT3, the total gas and CH4 production and archaeal and protozoal populations decreased as the concentration of tannins increased. Our results confirm that tannins suppress methanogenesis by reducing methanogenic populations in the rumen either directly or by reducing the protozoal population, thereby reducing methanogens symbiotically associated with the protozoal population. In addition, tannin sources containing both HT and CT were more potent in suppressing methanogenesis than those containing only HT.
Aims: To quantitatively analyse the faecal bacterial communities of Holstein calves and track their succession up to 12 weeks of age.
Methods and Results: Faecal samples obtained from four female ...Holstein calves were analysed by the RNA‐based, sequence‐specific rRNA cleavage method. Twelve scissor probes covering major rumen bacterial groups were used, detecting c. 60–90% of the total 16S rRNAs. At 1 week of age, 16S rRNAs from members of the Bacteroides‐Prevotella group (40·0% of the total 16S rRNAs), Faecalibacterium (21·7%), the Clostridium coccoides–Eubacterium rectale group (16·7%) and the Atopobium cluster (10·9%) were detected at high levels. Throughout the 12‐week period, rRNAs of the Bacteroides‐Prevotella and the Cl. coccoides‐Eu. rectale groups constituted the major fraction of microbiota (c. 50–70% of the total). The relative abundances of the Atopobium cluster, Faecalibacterium, and some probiotic bacteria (such as those of the genera Lactobacillus and Bifidobacterium) decreased as the animal aged. Instead, an uncultivated rumen bacterial group, as well as Ruminococcus flavefaciens and Fibrobacter emerged at the detectable levels (1–2%) in the faeces sampled at a postweaning age. In addition, certain bacterial groups that were not covered by the probe suite increased as the animals aged.
Conclusions: Young calves undergo dynamic changes in their intestinal bacterial community during the first 12 weeks of life. As young ruminants undergo metabolic and physiological development in their digestive tracts in the transition from a monogastric to a ruminant animal at an early age, the intestinal bacterial community may reflect such development.
Significance and Impact of the Study: The succession of the bacterial communities in the faeces of calves was quantitatively monitored in the present study for the first time. The approach used here was demonstrated to be a useful means for determining the populations of predominant faecal bacterial groups in a variety of calf experiments in response to diet, stress and disease.
An in vivo study was carried out to determine the effect of consuming probiotic lactobacilli-containing yogurt on the composition of microbiota in the human gut. Fifteen healthy adults ingested a ...daily serving of one of three commercial yogurts (two of the products contained a probiotic lactobacilli strain) for 20 days. Fecal samples at defined time points before, during, and after the period of yogurt ingestion were collected and analyzed. The fecal population of lactobacilli was determined by a culture-based method and subsequent colony PCR for the identification of species. Six predominant bacterial groups in the fecal samples were quantitatively determined based on a sequence-specific SSU rRNA cleavage method coupled with a suite of oligonucleotide probes, which was optimized for the target-specific detection of bacterial groups inhabiting human feces. In the ingestion period, one probiotic strain was detected in the feces of all five subjects who consumed the yogurt containing the strain, while the other strain was detected in three of another five subjects. The population levels of the two major groups (
Bacteroides and
Prevotella, and the
Clostridium coccoides–
Eubacterium rectale group) in the fecal samples tended to change in response to the ingestion but the change did not seem to be dependent on the product-specific property of each yogurt. These results suggest that the human fecal bacterial community could be altered by ingesting yogurt, although whether probiotic lactobacilli are present or absent in the yogurt does not seem to be a factor in this change.
Este estudio determinó el efecto de la administración in ovo y post-eclosión de extracto acuoso de hongo ostra (AEOM) sobre la respuesta inmune, la morfometría de tibias y minerales, y la histología ...de la médula ósea de pollos de engorde. Cuatrocientos huevos fértiles de la cepa de pollo de engorde Arbor acre fueron adquiridos, fumigados y pesados. Posteriormente, se colocaron 360 huevos en la incubadora. En el día 14 de incubación, los huevos fueron velados y un total de 273 huevos (75,83 % de fertilidad) que mostraban embriones viables se distribuyeron en tres grupos para la administración in ovo de AEOM que se llevó a cabo el día 18 de edad embrionaria. A cada grupo se le asignaron 91 huevos. Un total de ciento noventa y un (191) polluelos de un día de edad eclosionaron después de la incubación; 83 pollitos nacieron del control (91,20% de incubabilidad), 58 pollitos del grupo 2 (63,74%) y 50 nacieron del grupo 3 (incubabilidad del 54,95%). Los polluelos de grupos que habían recibido AEOM por vía in ovo se les administró oralmente AEOM inmediatamente después de la eclosión. Por lo tanto, resultando en tres tratamientos; T1 (control), T2 (0,1 ml in ovo + 0,1 ml post-hatch AEOM) y T3 (0,2ml in ovo + 0,2 ml post-hatch AEOM). Las aves fueron asignadas en 5 réplicas de 10 aves por réplica y criadas durante 8 semanas. Los datos fueron sometidos a un análisis unidirectorio de la varianza en un diseño completamente aleatorizado. Las aves en T2 registraron significativamente (P
The present study was undertaken to explore the methane reduction potential of phyto-sources from the foothills of
Himalayan
region. The qualitative screening of phyto-sources confirmed the presence ...of tannins in ~ 80% of the samples. Similarly, most of the phyto-samples were also possesses flavanoids (66%) and terpenoids (94%); however, none of the samples consist saponins or phlobatannins. The highest tannins concentration was reported in
Terminalia chebula
(245 g/kg DM),
Zanthoxylum alatum
(219 g/kg DM) and
Punica granatum
(207 g/kg DM). Phyto-sources such as
Pittosporum eriocarpum
,
Prunusdomestica
and
Berberis lycium
contain condensed and hydrolysable tannins in nearly equal proportions and comparatively produce lesser methane than non-tanniniferous phyto-sources sources or phyto-sources which possess either condensed or hydrolysable tannins. The study established that entodinomorphs were most vulnerable protozoa to tanniniferous phyto-sources. The attenuation of tannins impact through polyethylene glycol (PEG-6000) addition revealed a substantial increase in total volatile fatty acids (up to 23%) and ammonia nitrogen (up to 50%). It can be inferred from the study that
Prunus domestica, Berberis lycium
and
Terminalia chebula
due to their methane mitigation potential can be incorporated in animal feed for reducing methane emission. The present study unequivocally demonstrated that tannins-containing phyto-sources could be of great interest in the development of novel anti-methanogenic feed additives. However, the optimization of level of inclusion for the selected phyto-sources in animals diet should be studied.
Kale, a cultivar of Brassica oleracea, has attracted a great deal of attention because of its health-promoting effects, which are thought to be exerted through modulation of the intestinal ...microbiota. The present study was performed to investigate the effects of kale ingestion on the gastrointestinal microbial ecology of mice. 21 male C57BL/6J mice were divided into three groups and housed in a specific pathogen-free facility. The animals were fed either a control diet or experimental diets supplemented with different commercial kale products for 12 weeks. Contents of the caecum and colon of the mice were processed for the determination of active bacterial populations by a bacterial rRNA-based quantification method and short-chain fatty acids by HPLC. rRNAs of Bacteroides-Prevotella, the Clostridium coccoides-Eubacterium rectale group, and Clostridium leptum subgroup constituted the major fraction of microbiota regardless of the composition of the diet. The ratio of Firmicutes to Bacteroidetes was higher in the colon samples of one of the kale diet groups than in the control. The colonic butyrate level was also higher with the kale-supplemented diet. Overall, the ingestion of kale tended to either increase or decrease the activity of specific bacterial groups in the mouse gastrointestinal tract, however, the effect might vary depending on the nutritional composition.
To develop a suite of group-specific, rRNA-targeted oligonucleotide scissor probes for the quantitative detection of the predominant bacterial groups within the ruminal microbial community with the ...rRNA cleavage reaction-mediated microbial quantification method. Oligonucleotides that complement the conserved sites of the 16S rRNA of phylogenetically defined groups of bacteria that significantly contribute to the anaerobic fermentation of carbohydrates in ruminal ecosystems were selected from among published probes or were newly designed. For each probe, target-specific rRNA cleavage was achieved by optimizing the formamide concentration in the reaction mixture. The set of scissor probes was then used to analyse the bacterial community in the rumen fluids of four healthy dairy cows. In the rumen fluid samples, the genera Bacteroides/Prevotella and Fibrobacter and the Clostridium coccoides-Eubacterium rectale group were detected in abundance, accounting for 44-48%, 2·9-10%, and 9·1-10% of the total 16S rRNA, respectively. The coverage with the probe set was 71-78% of the total bacterial 16S rRNA. The probe set coupled with the sequence-specific small-subunit rRNA cleavage method can be used to analyse the structure of a ruminal bacterial community. The probe set developed in this study provides a tool for comprehensive rRNA-based monitoring of the community members that dominate ruminal ecosystems. As the ruminal microbial community can be perturbed, it is important to track its dynamics by analysing microbiological profiles under specific conditions. The method described here will provide a convenient approach for such tracking.
We developed a rapid and simple method for rRNA-based quantitative detection of a specific group of microorganisms in complex ecosystems. The method relies on the sequence-specific scission of 16S ...rRNA with ribonuclease H (RNase H) and oligonucleotides that specifically hybridize with targeted rRNA molecules. RNAs from a complex community were first mixed with an oligonucleotide and were subsequently digested with RNase H to achieve sequence-dependent rRNA cleavage at the hybridization site. For the quantitative detection of targeted rRNAs, the resulting RNA fragment patterns were analyzed by gel-electrophoresis, which separated and quantified cleaved and intact rRNA fragments. This method enabled the quantitative detection of microbes in a complex microbial community by a relatively simple and fast experimental procedure. We then applied the cleavage method to actual anaerobic microbial communities such as digested sewage sludge and UASB sludges. The results demonstrated that the present method was fully applicable to anaerobic digestor ecosystems containing complex anaerobic microorganisms.
•Changes in reticular pH during the close-up period in dairy cows were monitored.•SARA cows in the period had typical pH profiles compared to non-SARA cows.•The effects of yeast supplementation on ...reducing the risk of SARA were also evaluated.•Yeast supplementation did not prevent the postpartum decrease in reticular pH.
To determine changes in reticular pH during the pre- and postpartum periods, when subacute ruminal acidosis (SARA) frequently occurs, we monitored pH in dairy cows up to 12 weeks postpartum using a radio transmission pH sensing system. We designated seven pregnant multiparous Holstein cows for continuous pH monitoring (pH monitoring test), resulting in successful data acquisition for reticular pH. We subsequently evaluated the cows to determine whether active dry yeast supplementation of their feed was effective for SARA prevention (yeast supplementation test). Twenty- nine pregnant cows were allocated to two groups (control CON, n=15 and yeast- supplemented YEA, n=14) and fed a mixed ration optimized for dry prepartum cows and a mixed ration that consisted mainly of timothy hay and a commercial concentrate. The feed of the YEA group was supplemented with 10g/day of commercial active yeast product for three weeks prepartum and twelve weeks postpartum. In the latter test, six cows in each group were selected for reticular pH recording using the pH monitoring system. The pH profiles in the pH monitoring test were relatively high compared to those in the yeast supplementation test throughout the testing period, probably due to differences in starch and fiber levels between experiments despite their identical formula design. Notably, regardless of yeast supplementation, 11 of 12 cows in the latter test exhibited similar trends of pH maintenance (6.5<pH<6.8) or gradual decrease during the dry period, whereas average daily reticular pH decreased dramatically after calving. Supplementing the diet of dairy cows with yeast during the transition period provided no significant change in the health and performance measurements of the animals. We demonstrated the application of a radio transmission pH sensing system for assessment and monitoring of the ruminal pH of cows in the transition period. Furthermore, our results imply that SARA incidence in the transition and early- to mid-lactation periods may be attributable to a reticuloruminal pH decrease during the dry period, which is difficult to overcome by means of yeast supplementation during the transition period.
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