Effect of Essential Oil Active Compounds on Rumen Microbial
Fermentation and Nutrient Flow in In Vitro Systems
L. Castillejos, S. Calsamiglia,1 and A. Ferret
Grup de Recerca en Nutricio´ , Maneig i Benestar Animal, Departament de Cie`ncia Animal i dels Aliments,
Universitat Auto`noma de Barcelona, 08193 Bellaterra, Spain
pdf ABSTRACT: Two experiments were conducted to determine the effects of several essential oil active compounds on rumen microbial fermentation. In the first experiment, 4 doses (5, 50, 500, and 5,000 mg/L) of 5 essential oil compounds were evaluated using in vitro 24-h batch culture of rumen fluid with a 60:40 forage:concentrate diet (18% crude protein; 30% neutral detergent fiber). Treatments were control (CON), eugenol (EUG), guaiacol, limonene, thymol (THY), and vanillin. After 24 h, the pH was determined, and samples were collected to analyze ammonia N and volatile fatty acids (VFA). The highest dose of all compounds decreased total VFA concentration and increased the final pH. Eugenol at 5 mg/L tended to reduce the proportion of acetate and the acetate to propionate ratio, at 50 and 500 mg/L tended to reduce ammonia N concentration, and at 500 mg/L reduced the proportion of propionate and branchedchain VFA concentration, without affecting total VFA concentration. All other treatments had minor effects or changes occurred only after total VFA concentration decreased. In the second experiment, 8 dual-flow continuous culture fermenters (1,320 mL) were used in 3 replicated periods (6 d of adaptation and 3 d of sampling) to study the effects of THY and EUG on rumen microbial fermentation. Fermenters were fed 95 g/d of DM of a 60:40 forage:concentrate diet (18% crude protein; 30% neutral detergent fiber). Treatments were CON, 10 mg/L of monensin (positive control), and 5, 50, or 500 mg/L of THY and EUG, and were randomly assigned to fermenters within periods. During the last 3 d of each period, samples were taken at 0, 2, 4, and 6 h after the morning feeding and analyzed for peptides, amino acids, and ammonia N concentrations, and total and individual VFA concentrations. Monensin changed the VFA profile as expected, but inhibited nutrient digestion. Eugenol and THY decreased total VFA concentration and changed the VFA profile, and only 5 mg/L of THY tended to reduce the proportion of acetate, increased the proportion of butyrate, and increased the large peptidesNconcentration without decreasing total VFA concentration. Most of these essential oil compounds demonstrated their antimicrobial activity by decreasing total VFA concentration at high doses. However, EUG in batch fermentation and 5 mg/L of THY in continuous culture modified the VFA profile without decreasing total VFA concentration, and EUG in batch fermentation decreased ammonia N concentration.
Key words: essential oil, thymol, eugenol, rumen fermentation
Effects of alfalfa extract, anise, capsicum, and a mixture of cinnamaldehyde
and eugenol on ruminal fermentation and protein degradation
in beef heifers fed a high-concentrate diet1
P. W. Cardozo,* S. Calsamiglia,*2 A. Ferret,* and C. Kamel†
*Animal Nutrition, Management, and Welfare Research Group, Departament de Cie`ncia
Animal i dels Aliments, Universitat Auto`noma de Barcelona, 08193, Bellaterra, Spain;
†Pancosma SA, 01200-Bellegarde-sur-Valserine, Cedex, France
pdf ABSTRACT: Four Holstein heifers (360 ± 22 and 450 ± 28 kg of BW in Exp. 1 and 2, respectively) fitted with ruminal trocars were used in 4 × 4 Latin square designs to evaluate the effects on ruminal microbial fermentation of the following: Exp. 1, no additive, alfalfa extract (30 g/d, AEX), a mixture of cinnamaldehyde (0.18 g/d) and eugenol (0.09 g/d; CIE1), and AEX and CIE1 in combination; and Exp. 2, no additive, anise oil (2 g/d), capsicum oil (1 g/d), and a mixture of cinnamaldehyde (0.6 g/d) and eugenol (0.3 g/d). Heifers were fed a 90:10 concentrate:barley straw diet (16% CP; 25% NDF) for ad libitum intake. Each period consisted of 15 d for adaptation and 6 d for sampling. On d 16 to 18, DM and water intakes were measured. On d 19 to 21 ruminal contents were sampled at 0, 3, 6, 9, and 12 h after feeding to determine ruminal pH and the concentrations of VFA, L-lactate, large peptides, small peptides plus AA (SPep+AA), and ammonia N. On d 20 and 21, samples of ruminal fluid were collected at 0 and 3 h after feeding to determine protozoal counts. In Exp. 1, CIE1 and AEX decreased (P< 0.05) total DMI, concentrate DMI, and water intake. The increase (P < 0.05) in SPep+AA and the decrease (P < 0.05) in ammonia N when supplementing CIE1 suggest that deamination was inhibited. Treatment AEX increased (P < 0.05) the acetate to propionate ratio, which is less efficient for beef production. Treatment CIE1 increased (P< 0.05) counts of holotrichs. Effects of AEX and CIE1 were not additive for many of the measured metabolites. In Exp. 2, treatments had no effect on ruminal pH, total VFA concentration, and butyrate proportion. The capsicum oil treatment increased (P < 0.05) DMI, water intake, and SPep+AA N concentration and decreased (P < 0.05) acetate proportion, branched-chain VFA concentration, and large peptide N concentration. The cinnamaldehyde (0.6 g/d) and eugenol (0.3 g/d) treatment decreased (P < 0.05) water intake, acetate proportion, branchedchain VFA, L-lactate, and ammonia N concentrations
and increased (P < 0.05) propionate proportion and SPep+AA N concentration. The anise oil treatment decreased (P < 0.05) acetate to propionate ratio, branchedchain VFA and ammonia N concentrations, and protozoal counts. The results indicate that at the doses used a mixture of cinnamaldehyde and eugenol, anise oil, and capsicum oil may be useful as modifiers of rumen fermentation in beef production systems.
Key words: plant extract, rumen fermentation
Effects of carvacrol and cinnamaldehyde on intake, rumen fermentation, growth performance, and carcass characteristics of growing lambs
A.V. Chaves a,b, K. Stanford c, L.L. Gibson d, T.A. McAllister b, C. Benchaar a,
a Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Centre,
P.O. Box 90 – STN Lennoxville, Sherbrooke, Quebec, Canada J1M 1Z3
b Agriculture and Agri-Food Canada, Research Centre, P.O. Box 3000, Lethbridge, Alberta, Canada T1J 4B1 c Alberta Agriculture and Food, 5401-1st Ave. S. Lethbridge, Alberta, Canada T1J 4V6 d Agriculture and Agri-Food Canada, Research Centre, 6000 C&E Trail, Lacombe, Alberta, Canada T4L 1W1
pdf Abstract: Effects of essential oil compounds (EOC) on feed intake, ruminal fermentation, growth performance, and carcass characteristics were determined using 60 lambs (24.6±0.77 kg initial live weight, LW) fed either a barley- or corn grain-based diet without supplementation (control), or supplemented with 0.2 g/kg (DM basis) of carvacrol (CAR) or cinnamaldehyde (CIN). The experimental diets were arranged as a 2×3 factorial with 11-week periods and fed to lambs ad libitum. Ruminal pH tended (P=0.06) to be lower and total volatile fatty acid (VFA) concentration was higher (P<0.01) for barley- versus corn-based diets. Addition of EOC reduced (P=0.02) ruminal pH and increased (P=0.03) total VFA concentration versus the control. Acetate and propionate molar proportions and ammonia concentration did not differ among treatments. Inclusion of EOC in barley- or corn-based diets did not alter dry matter intake or average daily gain of lambs. Lambs fed the control diets tended (P=0.10) to have lighter livers than those fed diets containing EOC. Neither type of grain nor inclusion of EOC substantially affected sensory attributes of lamb sirloins.
Keywords: Carvacrol; Cinnamaldehyde; Ruminal fermentation; Growth performance; Carcass quality