Please cite this article in press as: Ishlak, A., et al., The effects of cinnamaldehyde, monensin and quebracho condensed tannin on rumen fermentation, biohydrogenation and bacteria in continuous culture system. Anim. Feed Sci. Tech. (2015) b s t r a c tThe objective of this experiment was to evaluate the effects of different feed additives (cinnamaldehyde, monensin, and quebracho condensed tannin extract) on fermentation, trans fatty acids (FA) formation and selected strains of rumen bacteria. Four continuous culture systems were used in 4 × 4 Latin square designs with 4 periods of 10 days each. Treatment diets were: control diet (44:56 forage to concentrate; CON), control plus cinnamaldehyde (CIN) at 400 mg/L, control plus monensin (MON) at 12 mg/L, and control with quebracho condensed tannin extract (QTAN) at 100 g/kg of diet (DM basis). Fermenters were fed treatment diets three times daily at 120 g/day and overflow (effluent) samples were collected from each fermenter on days 8, 9 and 10 of each period to estimate nutrients digestibility and FA composition. On day 10 of each period, three samples were collected from each fermenter at 3 and 6 h post morning feeding for volatile fatty acids (VFA), ammonia-N and bacterial analyses. Compared with the CON diet, feed additives had no effects (P > 0.05) on apparent dry matter (DM), neutral detergent fiber (NDF) and organic matter (OM) digestibility but apparent protein digestibility decreased (P < 0.01) with the QTAN and CIN diets. Compared with the CON diet, the concentration of acetate decreased (P < 0.05) with the MON and CIN diets. The concentration of propionate increased (P < 0.05) with the MON and QTAN diets and was greatest with the MON diet. Ammonia-N concentration decreased (P < 0.01) with all feed additives and was least with the QTAN diet. The concentration of C18:0 decreased (P < 0.01) with the three feed additives and was least with the MON diet. Concentration of trans C18:1 and vaccenic acid (VA) increased (P < 0.05) with the MON and CIN diets and was greatest with the MON diet. Compared with the CON diet, the concentration of c9t11CLA increased (P < 0.05) only with the QTAN diet. The DNA abundance of Butyrivibrio proteoclasticum decreased (P < 0.05) with the MON and CIN diets while the DNA abundance for Butyrivibrio VA increased (P < 0.05) with all feed additives compared with the CON diet. Feed additives had no effects (P > 0.05) on the DNA abundance of Anaerovibrio lipolytica and Butyrivibrio SA.In conclusion, results demonstrate that the feed additives used in this study affected the fermentation and biohydrogenation process.

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ABSTRACT:The effects of adding essential oils (EO) at different levels (125, 250, 500 mg/l) on rumen fermentation and biohydrogenation were examined in a rumen batch culture study. Treatments were: control without EO (CON), control with anise oil (ANO), cedar wood oil (CWO), cinnamon oil (CNO), eucalyptus oil (EUO), and tea tree oil (TEO). Essential oils, each dissolved in 1 ml of ethanol, were added to the culture flask containing 40 ml of buffer solution, 2 ml of reduction solution, 10 ml of rumen fluid, 25 mg of soybean oil, and 0.5 g of the diet. After 24 h of incubation in a water batch at 39°C, three samples were collected from each flask and analyzed for ammonia-N, volatile fatty acids (VFA), and fatty acids (FA). Expect for CNO, the proportions of acetate, propionate, and acetate to propionate ratios were not affected (P > 0.05) by EO addition. Addition of CWO, CNO, and TEO reduced total VFA concentrations (P < 0.05) regardless of dose level. The ammonia-N concentration was greater in cultures incubated with EO regardless of dose level. Compared with the CON, the concentrations of C18:0 and trans C18:1 were reduced (P < 0.05) with EO addition regardless of dose level. Compared with the CON, the concentration of linoleic acid was greater (P < 0.05) when EO were added at 500 mg/l. EO tested in this study had no effects on VFA profile but significantly reduced the formation of biohydrogenation products (C18:0 and trans C18:1).

Conjugated linoleic acids (CLA) have recently attracted significant attention because of their health benefits in a variety of models of metabolic and chronic inflammatory diseases. Among the many CLA isomers, c9t11 CLA has received the most attention because of its recognized health benefits as a cancer chemopreventive (Kennedy et al., 2010;Crumb 2011). The c9t11CLA is synthesized either in the rumen as an intermediate during the biohydrogenation of linoleic and linolenic acids (Harfoot and Hazlewood, 1987;Lee and Jenkins, 2011) AbstrAct: The effects of six essential oils (EO) on rumen fermentation and biohydrogenation were evaluated under in vitro conditions. Three doses (125, 250, and 500 mg/l) of EO were evaluated using in vitro 24 h batch culture of rumen fluid with a 55 : 45 forage : concentrate diet. Treatments were control (CON), control with Siberian fir needle oil (FNO), citronella oil (CTO), rosemary oil (RMO), sage oil (SAO), white thyme oil (WTO), and clove oil (CLO). Treatments were incubated in triplicate in 125 ml flasks containing 500 mg of finely ground total mixed ration (TMR), 25 mg of soybean oil, 10 ml of the strained ruminal fluid, 40 ml of media, and 2 ml of reducing solution. After 24 h, the pH was determined and samples were collected to analyze ammonia N, volatile fatty acids (VFA), and fatty acids (FA). Cultures pH was not affected by EO averaging 6.6 ± 0.2. In general, high EO doses reduced the total VFA concentration except for SAO and RMO. Relative to CON, all EO decreased (P < 0.05) ammonia N concentrations except for the highest dose of WTO. Except for SAO, EO did not modify acetate to propionate ratio. Relative to CON, the addition of CTO and FNO increased (P < 0.05) the proportions of isobutyrate and decreased (P < 0.05) the proportions of valerate and isovalerate. The concentrations (mg/culture) of C18:0 and C18:1 trans FA decreased (P < 0.05) with CTO, FNO, RMO, and SAO relative to CON. Most tested EO in this study had little to no effects on conjugated linoleic acids (CLA), and linoleic and linolenic acids concentrations. In conclusion, results from this study showed that except for effects on ammonia N, EO tested in this study had moderate effects on rumen fermentation. The reduction in the formation of trans FA and C18:0 with some EO may indicate shifts in the biohydrogenation pathways toward the formation of other unidentified intermediate FA. Keywords: plant extracts; volantile fatty acids; trans fatty acids; in vitroAbbreviations: CLA = conjugated linoleic acids; CLO = clove oil; CON = control; CTO = citronella oil; EO = essential oils; FA = fatty acids; FNO = Siberian fir needle oil; RMO = rosemary oil; SAO = sage oil; TMR = total mixed ration; VFA = volatile fatty acids; WTO = white thyme oil

The objective of this study was to evaluate the effects of forage level and oil supplement on selected strains of rumen bacteria believed to be involved in biohydrogenation (BH). A continuous culture system consisting of four fermenters was used in a 4×4 Latin square design with a factorial arrangement of treatments, with four 10 d consecutive periods. Treatment diets were: i) high forage diet (70:30 forage to concentrate (dry matter basis); HFC), ii) high forage plus oil supplement (HFO), iii) low forage diet (30:70 forage to concentrate; LFC), and iv) low forage plus oil supplement (LFO). The oil supplement was a blend of fish oil and soybean oil added at 1 and 2 g/100 g dry matter, respectively. Treatment diets were fed for 10 days and samples were collected from each fermenter on the last day of each period 3 h post morning feeding. The concentrations of vaccenic acid (t11C18:1; VA) and c9t11 conjugated linoleic acid (CLA) were greater with the high forage diet while the concentrations of t10 C18:1 and t10c12 CLA were greater with the low forage diet and addition of oil supplement increased their concentrations at both forage levels. The DNA abundance of Anaerovibrio lipolytica, and Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) were lower with the low forage diets but not affected by oil supplement. The DNA abundance of Butyrivibrio fibrisolvens stearic acid producer subgroup (Butyrivibrio SA) was not affected by forage level or oil supplement. In conclusion, oil supplement had no effects on the tested rumen bacteria and forage level affected Anaerovibrio lipolytica and Butyrivibrio VA.