Effects of a commercial blend of essential oils and monensin in a high-grain diet containing wheat distillers’ grains on in vitro fermentation

Abstract

Li, Y. L., Li, C., Beauchemin, K. A. and Yang, W. Z. 2013. Effects of a commercial blend of essential oils and monensin in a high-grain diet containing wheat distillers’ grains on in vitro fermentation. Can. J. Anim. Sci. 93: 387–398. Our objective was to evaluate in vitro effects of a commercial blend of essential oils (BEO) versus monensin (MON) on fermentation of a high-grain diet containing wheat distillers’ dried grains with solubles (DDGS). Two experiments were conducted. The first experiment was designed as a short-term batch culture to determine the optimum dose of BEO (0, 45, 90 or 180 mg kg−1 DM) on fermentation variables. The second experiment was a completely randomized block design with a 2×2 factorial arrangement of treatments using the rumen simulation technique. A high-grain dietary substrate containing wheat DDGS was supplemented with 0 or 28 mg MON kg−1 DM combined with 0 and 90 mg BEO kg−1 DM. Monensin did not affect the total volatile fatty acid (VFA) concentration or the molar proportions of individual VFA, but reduced CH4 production (mL L−1 gas; P=0.01) and disappearance of DM (P=0.04). Supplementation of BEO did not affect VFA concentration, but decreased (P=0.01) the molar proportion of acetate and reduced (P=0.02) the acetate to propionate concentration ratio and CH4 production (mL g−1 digested organic matter). The BEO increased (P=0.01) disappearance of neutral detergent fiber without affecting disappearance of other nutrients. These results indicate that supplementation of high-grain dietary substrate containing wheat DDGS with BEO improved fermentation pattern by increasing propionate concentration, reducing CH4 production, and increasing fiber digestibility. This commercial BEO could be a potential substitute for MON for beef cattle fed high-grain diets containing DDGS.

Screening of live yeast and yeast derivatives for their impact of strain and dose on in vitro ruminal fermentation and microbial profiles with varying media pH levels in high‐forage beef cattle diet

“…In comparison with yeast products, the lower DMD with supplementary Mon at either pH 5.8 or pH 6.5 in the present study could partly be a result of the lower amount of fibrolytic bacteria (F. succinogenes). In agreement with the present study, Li et al 41 found a negative effect of Mon on copy number of F. succinogenes in a high-grain diet on in vitro fermentation. Moreover, although the propionate proportion was lower and the A:P ratio was greater with LY or YD than Mon at either pH 5.8 or pH 6.5, its greater DMD along with a higher total VFA concentration is of interest, particularly with a high-forage diet or a low rumen pH.…”

“…In comparison with yeast products, the lower DMD with supplementary Mon at either pH 5.8 or pH 6.5 in the present study could partly be a result of the lower amount of fibrolytic bacteria ( F. succinogenes ). In agreement with the present study, Li et al . found a negative effect of Mon on copy number of F. succinogenes in a high‐grain diet on in vitro fermentation.…”

Effects of essential oils from African basil on fermentation ofAndropogon gayanusgrass in the Artificial Rumen (RUSITEC)

“…A portion of the (NH 4 ) 2 SO 4 in McDougall's buffer solution was replaced with 15 Nenriched (NH 4 ) 2 SO 4 (Sigma Chemical Co., minimum 15 N enrichment 1 g L (1 ) from day 8 until the end of the experiment as described by Li et al (2013). The background 15 N was determined from a volume of 250 mL of effluent (preserved in a solution of azide) sampled from each collection flask and the removed 48-h feedbags on day 8, before the addition of 15 N-enriched (NH 4 ) 2 SO 4 to the McDougall's buffer solution.…”

“…RUSITEC systems were operated in a manner similar to that previously described by Li et al (2013). Fermenters were inoculated with 180 mL of artificial saliva (McDougall's 1948) …”

“…Prior to gas measurement on days 8Á16, a 10-mL sample of gas was obtained from the septum of collection bags using a 26-gauge needle (Becton Dickinson, Franklin Lakes, NJ) and transferred to evacuated 6.8-mL exetainers (Labco Ltd., Wycombe, Bucks, UK) for later analysis of daily methane concentration (Chaves et al 2006;Fraser et al 2007). The 48-h feedbags removed from each fermenter were processed to determine apparent DM disappearance (DMD) from day 8 to the end of the experiment as described by Li et al (2013). Dried residues from feedbags removed on the last 4 d were ground through a 1-mm screen and analyzed for neutral detergent fiber (NDF) according to Van Soest et al (1991) to determine NDF disappearance (NDFD) with heat-stable a-amylase and sodium sulphite being used in the NDF procedure and expressed inclusive of residual ash.…”