Rumen fermentation and production effects of Origanum vulgare L. leaves in lactating dairy cows

Abstract

A lactating cow trial was conducted to study the effects of dietary addition of oregano leaf material (Origanum vulgare L.; OV; 0, control vs. 500 g/d) on ruminal fermentation, methane production, total tract digestibility, manure gas emissions, N metabolism, organoleptic characteristics of milk, and dairy cow performance. Eight primiparous and multiparous Holstein cows (6 of which were ruminally cannulated) were used in a crossover design trial with two 21-d periods. Cows were fed once daily. The OV material was top-dressed and mixed with a portion of the total mixed ration. Cows averaged 80 ± 12.5 d in milk at the beginning of the trial. Rumen pH, concentration of total and individual volatile fatty acids, microbial protein outflow, and microbial profiles were not affected by treatment. Ruminal ammonia-N concentration was increased by OV compared with the control (5.3 vs. 4.3mM). Rumen methane production, which was measured only within 8h after feeding, was decreased by OV. Intake of dry matter (average of 26.6 ± 0.83 kg/d) and apparent total tract digestibly of nutrients did not differ between treatments. Average milk yield, milk protein, lactose, and milk urea nitrogen concentrations were unaffected by treatment. Milk fat content was increased and 3.5% fat-corrected milk yield tended to be increased by OV, compared with the control (3.29 vs. 3.12% and 42.4 vs. 41.0 kg/d, respectively). Fat-corrected (3.5%) milk feed efficiency and milk net energy for lactation (NE(L)) efficiency (milk NE(L) ÷ NE(L) intake) were increased by OV compared with the control (1.64 vs. 1.54 kg/kg and 68.0 vs. 64.4%, respectively). Milk sensory parameters were not affected by treatment. Urinary and fecal N losses, and manure ammonia and methane emissions were unaffected by treatment. Under the current experimental conditions, supplementation of dairy cow diets with 500 g/d of OV increased milk fat concentration, feed and milk NE(L) efficiencies, and tended to increase 3.5% fat-corrected milk yield. The sizable decrease in rumen methane production with the OV supplementation occurred within 8h after feeding and has to be interpreted with caution due to the large within- and between-animal variability in methane emission estimates. The OV was introduced into the rumen as a pulse dose at the time of feeding, thus most likely having larger effect on methane production during the period when methane data were collected. It is unlikely that methane production will be affected to the same extent throughout the entire feeding cycle.

Evaluation of the Effects of Mitigation on Methane and Ammonia Production by Using Origanum vulgare L. and Rosmarinus officinalis L. Essential Oils on in Vitro Rumen Fermentation Systems

“…Hristov et al [31] demonstrated a CH4 production reduction (−16.5, −11.7 and −13.6 g of methane per kg of DM intake) by three different doses of dietary oregano leaves (respectively 250, 500 and 750 g/animal per day) in dairy cows. Tekippe et al [32] found similar results in dairy cows fed by oregano leaves at a 500 g/d rate (40% reduction in methane production).…”

“…Lin et al [36] observed a NH3 inhibition with a mixture of EOs composed of clove, oregano, cinnamon and lemon in sheep (1 g/day). Contrasting results on in vivo NH3 production were found by Hristov et al [31] and Tekippe et al [32] by feeding dairy cows with a supplementation of oregano leaves. However, as confirmed by the present study, the positive effects of EOs on CH4 and NH3 production are frequently associated to negative effects on feed digestibility, especially at the highest doses [28,37,38].…”

Nutrient Composition, Forage Parameters, and Antioxidant Capacity of Alfalfa (Medicago sativa, L.) in Response to Saline Irrigation Water

“…of antioxidant-rich diets have been proposed. Dairy cows supplemented daily with 500 g of oregano (2082 μmoles·TE·g −1 DM) increased their milk fat concentration, feed and milk NEL efficiencies, and fat-corrected milk yield by 3.5% [67]. Although oregano has an ORAC value 8-9 fold higher than our oven-dried alfalfa shoots (225 to 256 μmoles·TE·g , which is 10-fold higher than the 500 g·day −1 oregano supplement from the above-mentioned study.…”

Nonequilibrium clumped isotope signals in microbial methane

“…The bovine rumen gas samples obtained for this study were collected from cannulated, lactating Holstein dairy cows at The Pennsylvania State University using methods described previously (59). The samples were stored at room temperature in glass serum vials stoppered with blue butyl septa.…”