Effects of a selection of additives on in vitro ruminal methanogenesis and in situ and in vivo NDF digestibility

Abstract

The effects of 18 essential oils, yeast, Quebracho tannin and Quillaja saponin on ruminal methane and gas production (GP) were studied in vitro. A lactating cow diet was incubated with rumen inoculum. Doses of the additives (mg/L) were: essential oils = 500; tannin = 67; yeast = 8.35 and 16.7; and saponin = 300. Lemongrass, estragole, eugenol, geraniol, limonen, thyme oil and thymol produced less gas (overall mean 33.8 mL/200 mg dry matter (DM)) than control (43.6 mL/200 mg DM; P < 0.001). Methane produced (mL/200 mg DM) by guaiacol (10.7), lemongrass (9.6), limonene (11.4), thyme oil (10.9) and thymol (2.1) was lower than control (12.5) (P < 0.001). Methane percentage on total GP was lower (P < 0.001) for cinnamic alcohol (25.4), guaiacol (24.5), thymol (19.7) and vanillin (26.3) than control (28.8). In a second experiment, thymol, guaiacol and yeast were added to the diet of dry fistulated cows to determine in situ neutral detergent fiber digestibility (NDFD) of six forages and in vivo dietary NDFD. Thymol and yeast decreased in situ NDFD after 24 h (33.9% and 33.5% vs. 38.1%; P = 0.008). Thymol decreased in vivo total tract NDFD (40.8% vs. 51.4%; P = 0.02). Differences in GP and methane levels were registered within classes of additives. A careful selection of additives may allow for the manipulation of ruminal fermentation.

<i>In vitro</i> ruminal dry matter and neutral detergent fibre digestibility of common feedstuffs as affected by the addition of essential oils and their active compounds

“…This appears to be consistent with the results of the present work showing a detrimental effect of THY-C on NDFD24 of TMR. Similar results were obtained by Pirondini et al (2015) who reported a reduced in situ and total tract NDFD of dry cows supplemented with 5 g • d −1 of THY-C. A decrease in acetate percentage was examined in vitro for THY-C on high fibre diet by Chaudhary et al (2016) and this could indicate a reduction in fibre digestibility. In summary, the negative effects on the NDFD24 were exerted mainly by phenylpropanoid-rich EO and EOC added to tested concentrate feeds and TMR, and by THY-C added to TMR.…”

“…Using the in situ method, Pirondini et al (2015) reported reduced NDFD in dry cows fed thymol and Nanon et al (2014) reported no effects of garlic and ginger oil mixture supplementation in cows. Similarly, in in vivo study on cows supplemented a mixture of natural and nature-identical EO components that included thymol, eugenol, vanillin, and limonene, there was reported no effect on total tract NDFD (Benchaar et al, 2006).…”

A Meta-analysis Describing the Effects of the Essential oils Blend Agolin Ruminant on Performance, Rumen Fermentation and Methane Emissions in Dairy Cows

“…Eugenol is a phenolic present in clove bud (Eugenia caryophyllus or Syzygium aromaticum) [27]. In vitro batch culture studies have shown positive rumen modulatory effects of coriander oil, eugenol [33], geraniol [7] and their blend Agolin on the rumen fermentation [6,7], suggesting a theoretical increase in the efficiency of energy and protein metabolism in the rumen [34]. This hypothesis is based on the negative effects of EO on the rumen hyperammonia-producing bacteria and the positive effect on the propionate-producing bacteria [35].…”

“…The main active compounds of this product are food grade and chemically-defined plant extracts including coriander (Coriandrum sativum) seed oil (up to 10%), eugenol (up to 7%), geranyl acetate (up to 7%) and geraniol (up to 6%) along with some preservatives such as fumaric acid. Various authors have recently studied the effect of Agolin Ruminant on rumen fermentation in vitro [6][7][8] and in vivo [8][9][10][11][12][13][14][15][16] showing positive but variable results. As the product is in the market, numerous on-farm studies with dairy cows have been conducted in different countries over recent years, although the results have not been generally published in peer reviewed journals.…”

Evaluation of the Effect of Four Essential Oils as Potential Alternatives for Monensin on Rumen Fermentation Characteristics and Nutrient Degradability

“…For instance, citral, the main active ingredient detected in C. citratus herein, significantly reduces GP in the rumen with notable antimicrobial action (Lin et al, 2013). Additionally, geraniol, a major component of C. nardus, exerts antimicrobial action against both Gram-negative and Gram-positive bacteria (Dorman and Deans, 2000) and reduces total GP when tested at 500 mg l -1 (Pirondini et al, 2015).…”