This experiment was designed to investigate the effects of different concentrations (0, 0.33, 0.66, 0.99, and 1.32 g/L) of a twin-strain of Saccharomyces cerevisiae live cells on in vitro mixed ruminal microorganism fermentation of corn starch, soluble potato starch, and sudangrass hay (60.5%, DM basis) plus concentrate mixture (39.5%, DM basis). Ruminal fluid was collected from two dairy cows, mixed with phosphate buffer (1:2), and incubated (30 mL) anaerobically at 38 degrees C for 6 and 24 h with or without yeast supplement, using 200 mg (DM basis) of each substrate. Medium pH, ammonia-N, and numbers of protozoa were unaffected (P = 0.38) by yeast cells in all substrates. Molar proportion of acetate was unchanged (P = 0.56) with cornstarch and soluble potato starch, but increased quadratically (P = 0.02) with hay plus concentrate by treatment. Addition of yeast cells caused a linear increase of total VFA (P = 0.008) in all substrates. Excluding the soluble potato starch, supplementation of S. cerevisiae resulted in a quadratic increase of propionate (P = 0.01), with a quadratic decrease (P = 0.04) of acetate:propionate. When soluble potato starch was used as a substrate, a linear increase (P = 0.006) of the molar proportion of propionate and a quadratic decrease (P = 0.007) in acetate:propionate was observed by treatment. Molar proportion of butyrate was unchanged (P = 0.35) with cornstarch and soluble potato starch, whereas it decreased linearly (P = 0.007) with hay plus concentrate by yeast cell supplementation. When cornstarch and soluble potato starch were used as a substrate, minor VFA were decreased (P = 0.05) by treatment. Accumulation of lactate was linearly decreased by treatment (P = 0.007) in all substrates. During incubation with hay plus concentrate, IVDMD was linearly increased (P = 0.006), whereas production of methane (linear; P = 0.02) and accumulation of hydrogen was decreased (quadratic; P = 0.005) by treatment after 24 h. These results showed that a twin strain of S. cerevisiae live cells stimulated in vitro mixed ruminal microorganism fermentation with decreased lactate, and a small decrease of methane and hydrogen with hay plus concentrate.

Four Holstein steers fed with Sorghum silage were used to examine the effect of fumaric acid supplementation (20g/kg. diet dry matter (DM)) on methane production, rumen fermentation, blood metabolism and feed digestibility.The protozoal population in the rumen was unaffected by fumaric acid supplementation.The postprandial ruminal concentration of ammonia-N decreased, and that of total volatile fatty acids tended to be higher with fumaric acid supplementation.The proportion of ruminal acetic acid was unaffected, but that of propionic acid increased and that of butyric acid decreased by fumaric acid. The postprandial blood plasma concentration of glucose was increased, whereas that of urea-N was decreased by fumaric acid. The plasma concentration of most of free amino acids was unaffected. Daily methane production decreased by 23.0% and carbon dioxide production decreased by 20.5% with fumaric acid supplementation. Apparent digestibility of dry matter and of neutral detergent fiber were not influenced by fumaric acid. These results indicated that fumaric acid was converted to propionic acid by rumen microorganisms, and that methane production from the rumen was reduced without lowering the ability to digest dietary fiber. However, some dietary conditions that alter the effectiveness of fumaric acid and the long term effect remain to be examined.

LAMLR with the hanging technique can be completed safely. The procedure can be performed by open liver surgeons; and thus may be widely performed in the future.

The effects of alpha-cyclodextrin-horseradish oil complex (CD-HR) on methane production and ruminal fermentation were studied in vitro and in steers. In the in vitro study, diluted ruminal fluid (30 mL) was incubated anaerobically at 38 degrees C for 6 h with or without CD-HR, using cornstarch as substrate. The CD-HR was added at various concentrations (0, 0.17, 0.85 and 1.7 g/L). Treatment affected neither the pH of the medium nor the number of protozoa. Total VFA increased in a linear manner (P = 0.02), and NH3-N decreased quadratically (P = 0.04) as the concentration of CD-HR increased from 0.17 g/L to 1.7 g/L. Molar proportions of acetate decreased in a linear manner (P = 0.03), and propionate increased linearly (P = 0.008) with increasing concentrations of CD-HR. Production of methane was inhibited up to 90%, whereas accumulation of dihydrogen was increased 36-fold by 1.7 g/L of CD-HR supplementation relative to controls. The effect of CD-HR on methane production, ruminal fermentation and microbes, and digestibility was further investigated in vivo using four Holstein steers in a crossover design. The CD-HR supplement was mixed into the concentrate portion of a (1.5:1) Sudangrass hay plus concentrate mixture that was fed twice daily to the steers. Ruminal samples were collected 0, 2, and 5 h after the morning feeding. No effects of CD-HR supplementation on ruminal pH (P = 0.63) or protozoal numbers (P = 0.44) were observed. Molar proportion of acetate was decreased (P = 0.04) and propionate was increased (P = 0.005) by CD-HR treatment. Molar proportion of butyrate was increased (P = 0.05) in CD-HR-supplemented steers. Ruminal NH3-N was decreased (P = 0.05) by treatment. Blood plasma glucose concentration was increased (P = 0.02) and urea-N was decreased (P = 0.04) with CD-HR supplementation. Daily DMI was decreased (P = 0.04), and apparent digestibility of DM (P = 0.13), NDF (P = 0.14), and CP tended (P = 0.14) to be increased by treatment. Methane production was decreased (P = 0.03) by 19%, and the number of methanogens was also decreased (P = 0.03). Although N retention (P = 0.11), total viable bacteria (P = 0.15), and sulfate-reducing bacteria (P = 0.17) were not significantly altered by treatment, tendencies for increases were noted with CD-HR supplementation. The number of cellulolytic (P = 0.38) and acetogenic bacteria (P = 0.32) remained unchanged by treatment. These results indicate that CD-HR supplementation can be used to decrease methane production in steers.

This experiment was designed to investigate the effects of different concentrations (0, 1.2, 1.8, 2.4, and 3.2 g/L) of sarsaponin on ruminal microbial methane production using the substrates soluble potato starch, cornstarch, or hay plus concentrate (1.5:1). Ruminal fluid was collected from a dairy cow, mixed with phosphate buffer (1:2) and incubated (30 ml) anaerobically at 38 degrees C for 6 and 24 h with or without sarsaponin. Excluding the lower level of sarsaponin, pH of the medium was slightly decreased. Ammonia-N concentration and numbers of protozoa were decreased in a dose-dependent manner. Total volatile fatty acids and total gas production were increased. Molar proportion of acetate was decreased and propionate was increased with a corresponding decrease in acetate:propionate ratio. Hydrogen production was decreased. As the concentration of sarsaponin increased from 1.2 to 3.2 g/L, fermentation of soluble potato starch, cornstarch, or hay plus concentrate decreased methane production from 20 to 60% (6 h) and 17 to 50% (24 h), 21 to 58% (6 h) and 18 to 52% (24 h), and 23 to 53% (6 h) and 15 to 44% (24 h), respectively. Excluding the lower dose concentration (1.2 g/L) of sarsaponin, in vitro disappearance of dry matter of hay plus concentrate was decreased after 24 h. In conclusion, these results show that sarsaponin stimulated the mixed ruminal microorganism fermentation as well as to inhibit methane production in vitro.

No abstract

Small luminescent molecular probes based on the iridium(III) complex BTP, (btp)2Ir(acac) (btp = benzothienylpyridine, acac = acetylacetone) have been developed for sensing intracellular and in vivo O2. These compounds are BTPSA (containing an anionic carboxyl group), BTPNH2 (containing a cationic amino group), and BTPDM1 (containing a cationic dimethylamino group); all substituents are incorporated into the ancillary acetylacetonato ligand of BTP. Introduction of the cationic dimethylamino group resulted in an almost 20-fold increase in cellular uptake efficiency of BTPDM1 by HeLa cells compared with BTP. The phosphorescence intensity of BTPDM1 internalized in living cells provided a visual representation of the O2 gradient produced by placing a coverslip over cultured monolayer cells. The intracellular O2 levels (pO2) inside and outside the edge of the coverslip could be evaluated by measuring the phosphorescence lifetime of BTPDM1. Furthermore, intravenous administration of 25 nmol BTPDM1 to tumor-bearing mice allowed the tumor region to be visualized by BTPDM1 phosphorescence. The lifetime of BTPDM1 phosphorescence from tumor regions was much longer than that from extratumor regions, thereby demonstrating tumor hypoxia (pO2 = 6.1 mmHg for tumor and 50 mmHg for extratumor epidermal tissue). Tissue distribution studies showed that 2 h after injection of BTPDM1 into a mouse, the highest distribution was in liver and kidney, while after 24 h, BTPDM1 was excreted in the feces. These results demonstrate that BTPDM1 can be used as a small molecular probe for measuring intracellular O2 levels in both cultured cells and specific tissues and organs.

The effect of the presence of protozoa on the composition of rumen bacteria was investigated in cattle. Seven castrated Holstein cattle were divided into two groups: four faunated and three unfaunated, and 16S ribosomal RNA gene (rDNA) clonal libraries were constructed. A total of 312 clones were sequenced across 1,500 bp. The 151 sequences of the faunated cattle were classified into 98 operational taxonomic units (OTUs) having at least 97% similarity. The sequences derived from the faunated cattle were classified into Firmicutes (59.7%), Bacteroidetes (34.4%), Spirochaetes (2.6%), Actinobacteria (2.0%), and Proteobacteria (1.3%). Bacteroides and Prevotella (34.4%) were the major groups in the faunated cattle. The 161 sequences in the unfaunated cattle were classified into 72 OTUs. The sequences derived from the unfaunated libraries were classified into Firmicutes (65.7%), Bacteroidetes (31.1%), Proteobacteria (1.9%), and Spirochaetes (1.2%). The Clostridium botulinum group and its relatives (36.0%) were the major groups in the unfaunated cattle. An analysis by the computer program LIBSHUFF clarified that the presence of ruminal protozoa markedly affected the composition of rumen bacteria.