Effects of Cinnamaldehyde and Garlic Oil on Rumen Microbial Fermentation in a Dual Flow Continuous Culture

Abstract

Eight continuous culture fermentors inoculated with ruminal liquor from heifers fed a 50:50 alfalfa hay:concentrate diet (17.6% crude protein, 28.0% neutral detergent fiber) were used in 3 replicated periods to study the effects of cinnamaldehyde (CIN) and garlic oil (GAR) on rumen microbial fermentation. Treatments were no additive (negative control); 1.25 mg/L (MON) and 12.5 mg/L (MON10) of the ionophore antibiotic monensin (positive control); 31.2 mg/L CIN (CIN) and 312 mg/L (CIN10) of CIN; and 31.2 mg/L GAR (GAR) and 312 mg/L (GAR10) of GAR (Allium sativa). The MON10 caused expected changes in microbial fermentation patterns (a decrease in fiber digestion, ammonia N concentration, and proportions of acetate and butyrate; an increase in the proportion of propionate; and a trend to increase small peptide plus AA N concentration). The CIN decreased the proportion of acetate and branch-chained volatile fatty acids (VFA) and increased the proportion of propionate; CIN10 decreased the proportion of acetate and increased the proportion of butyrate compared with the control. The GAR10 increased the proportion of propionate and butyrate and decreased the proportion of acetate and branch-chained VFA compared with the control. The GAR10 also increased the small peptide plus amino acid N concentration, although no effects were observed on large peptides or ammonia N concentrations. The CIN and GAR10 resulted in similar effects as monensin, with the exception of the effects on the molar proportion of butyrate, which suggests that they might have a different mode of action in affecting in vitro microbial fermentation.

Effects of essential oils on proteolytic, deaminative and methanogenic activities of mixed ruminal bacteria

“…Similar to our results, Busquet et al (2005) also observed that monensin did not reduce CH 4 production to the same extent as garlic oil. In fact, Busquet et al (2005) speculated that garlic oil does not exert its effect on CH 4 production through the same mode of action as monensin (which specifically inhibits gram-positive bacteria), but rather through a direct inhibition of Archea microorganisms in the rumen. Collectively, these results suggest that the effects of EO and their components on CH 4 production are dosedependent and may vary with the type of EO and EOC used.…”

“…Monensin is known for its effects on VFA pattern in that it increases the proportion of propionate and decreases the proportion of acetate, although other studies (Fuller and Johnson 1981;Busquet et al 2005) also found no effects of monensin on acetate and propionate molar proportions. In fact, the effect of monensin on VFA pattern may be dose-dependent, as illustrated by Busquet et al (2005), who observed that at 12.5 mg L…”

Diet supplementation with cinnamon oil, cinnamaldehyde, or monensin does not reduce enteric methane production of dairy cows

“…Cardozo et al (2004) reported no changes in total VFA concentration and VFA molar proportions when CIN was supplied at 0.22 mg/l in continuous culture systems. At high doses, CDH (31.2 and 312 mg/l) reduced acetate proportion and increased the proportions of propionate and butyrate (Busquet et al, 2005). Lourenço et al (2008) reported that the addition of CDH at 500 mg/l in continuous culture systems dramatically decreased total VFA concentration, reduced propionate proportion and increased the proportions of acetate and butyrate.…”

“…In this regard, cinnamon oil (CIN) and its main component cinnamaldehyde (CDH) are of special interest because they have been shown to inhibit CH 4 production in vitro. For instance, Busquet et al (2005) observed in vitro that CDH decreased acetate proportion and increased propionate proportion, which should result in a reduction of CH 4 production given the inverse relationship between propionogenesis and methanogenesis in the rumen. In another in vitro study, Macheboeuf et al (2008) confirmed the antimethanogenic properties of CIN and CDH.…”

Design, implementation and interpretation of in vitro batch culture experiments to assess enteric methane mitigation in ruminants—a review

“…Such experimental approaches have allowed the mode of action of a range of chemicals (Busquet et al, 2005;Bodas et al, 2008;García-González et al, 2008;Durmic et al, 2010) and dietary substrates (Patra and Yu, 2013;Hatew et al, 2015) to be investigated. Use of IVFT offers the opportunity to evaluate a broad spectrum of chemical agents alone or in a number of combinations over a wide range of concentrations (e.g., Busquet et al, 2005;García-González et al, 2008). However, this technique does not generate reliable information for agents that are only effective for decreasing CH 4 emissions over an extended period (Castro-Montoya et al, 2015).…”